Epi-Ready - NEHA CERT Online Education
Transcription
Epi-Ready - NEHA CERT Online Education
Table of Contents Acknowledgements Epi-Ready Team Training Module 1: Passive Surveillance Task List Module 1 PowerPoint Presentation Table 1: Foodborne, waterborne, enteric illnesses log Module 2: Outbreak Determination Task List PowerPoint Presentation Interviewing Group Exercise: A Potential Outbreak? Interviewing Group Exercise: Interview Evaluation Module 3: Environmental Assessment Task List PowerPoint Presentation Module 4: Epidemiologic Investigation Task List PowerPoint Presentation Case Definition and Hypothesis Exercise Group Exercise: Joe’s Thanksgiving Dinner IAFP Form A IAFP Form C1 and C2 Module 5: Laboratory Guidance Task List PowerPoint Presentation Kit Contents for Collecting Samples During Investigation of Foodborne Outbreak Sources, Materials for Foodborne Disease Investigation Kits Module 6: Outbreak Concluding Actions Task List PowerPoint Presentation Example Report Template Example Final Report - Maple Rapids Church Youth Group Program Campylobacter jejuni Outbreak Final Exercise: A Case Study – Multistate Outbreak of E. coli 0157:H7 Appendices: Appendix 1: Foodborne Illness Glossary Appendix 2: Communications 1. Preparation 2. Outbreak Response 3. Termination Appendix 3: Interviewing Skills 1. Task List 2. Task List Related Information Appendix 4: Forms 1. Food Preparation Review 2. CDC Form 52.13/Spoon and Fork/EFORS 3. IAFP Form A 4. IAFP Form C1 5. IAFP Form C2 Appendix 5: Web-based Resources to Explore Appendix 6: Answer Sheets 1. Graduation Party Blues Exercise 2. Joe’s Thanksgiving Dinner Group Exercise ACKNOWLEDGEMENTS Epi-Ready Team Training reflects the efforts of many dedicated individuals, and foremost the Michigan Foodborne Illness Response Strategy (F.I.R.ST.) Workgroup who designed and successfully implemented this course in Michigan, and encouraged NEHA to utilize their course as the framework for Epi-Ready Team Training. Individuals on the F.I. R.S.T. Workgroup include Jennifer Beggs, Sally Bidol, Tom Buss, Joann Clinchoc, Janet Dorer, Sonja Hrabowy, Siobhan Kent, Whitney Mauer, Cindy Overkamp, Doug Park, Susan Shiflett, and John Tilden. NEHA’ s Epi-Ready Team Training course is made possible through a cooperative agreement with the Centers for Disease Control and Prevention, National Center for Infectious Diseases (CDC/NCID)-Food Safety Office. Special thanks go to Dr. Arthur P. Liang, Dr. Donald J. Sharp, and Richard Skibicki. Epi-Ready Team Training Advisory committee and contributing individuals: Art Bloom Rob Blake Elaine Brainerd Vickie Church Holly Coleman Cheryl Connelly Alicia Fry Nancy Gathany David Goldman Bob Harrington Ernest Julian Jimmy Lui George Nakamura Charles Otto J. Douglas Park Kenneth Pearson Lawrence Pong Fred Ramsey Cindy Roberts Michele Samarya-Timm Mark Schmidt Rebecca Shapack Susan Shiflett Julia Smith Past NEHA President; Portland, Oregon DeKalb County Board of Health; Atlanta, Georgia American Nurses Foundation; Washington, D.C San Diego Department of Environmental Health; San Diego, CA Chatham County Health Department; Apex, NC National Association of County and City Health Officials Centers for Disease Control and Prevention; Atlanta, GA Centers for Disease Control and Prevention; Atlanta, GA United States Department of Agriculture; Washington, D.C. Casper/Natrona County Health Department; Casper, WY State of Rhode Island Department of Health; Providence, RI Food Safety Web Specialists; Washington, D.C Contra Costa Health Services; Concord, CA Centers for Disease Control and Prevention; Atlanta, GA Food and Drug Administration; College Park, MD Knox County Health Department; Knoxville, TN San Francisco Environmental Health; San Francisco, CA United States Department of Agriculture; Albany, NY Food Safety Web Specialists; Washington, D.C. Franklin Township Health Department; Somerset, NJ Michigan Department of Community Health; Lansing, MI National Association of County and City Health Officials Michigan Department of Community Health; Lansing, MI Centers for Disease Control and Prevention; Atlanta, GA For additional information on this course, please contact: National Environmental Health Association 720 S. Colorado Blvd. Suite 1000-N Denver, CO 80246 Phone: (303) 756-9090 FAX: (303) 691-9490 www.neha.org © National Environmental Health Association August 2003 This educational material is the sole and exclusive property of the National Environmental Health Association. Any use, copying or reproduction of this material without written permission from NEHA is forbidden Epi-Ready Team Training Foodborne Illness Response Strategies Purpose The goal of this training is for public health professionals and other involved personnel to rapidly identify and investigate a foodborne disease outbreak to allow for implementation of control measures to reduce the incidence of foodborne illness. Overall Objectives At the end of this training, the participant will be able to: 1. Describe the process of gathering data through passive surveillance. 2. List criteria for beginning an outbreak investigation. 3. Describe the purpose of an environmental assessment. 4. Use epidemiological study data to identify outbreak cause(s). 5. List four steps for submitting samples to a laboratory for testing. 6. Document and report the results of an outbreak investigation. 7. Evaluate the similarities between incidental and intentional foodborne illness. (e.g. Bioterrorism link) Epi-Ready Foodborne Illness Response Strategies Special thanks to CDC’s Food Safety Office, particularly Dr. Art Liang, Dr. Don Sharp, and Richard Skibicki, as well as the Epi-Ready Advisory Committee and others who collaboratively gave unselfishly of their time and advice. © National Environmental Health Association 2005 Epi-Ready Foodborne Illness Response Strategies 2 ACKNOWLEDGEMENTS Individuals who served on the F.I.R.ST. workgroup: Sally Bidol Tom Buss Joann Clinchoc Sonja Hrabowy Whitney Mauer Cindy Overkamp Doug Park Susan Shiflett John Tilden Michigan Department of Community Health Grand Traverse County Health Department City of Detroit Health Department Michigan Department of Community Health Kent County Health Department Kalamazoo County Human Services Dept. Michigan Department of Agriculture Michigan Department of Community Health Michigan Department of Agriculture Epi-Ready Foodborne Illness Response Strategies 3 INTRODUCTION 1 Identify roles, responsibilities, and legal requirements Promote teamwork and consistency Answer commonly asked questions through Workbook Presentations Question and answer sessions Epi-Ready Foodborne Illness Response Strategies 4 Surveillance Prevention Measures Epidemiologic Investigation Applied Research Source: Centers for Disease Control and Prevention Epi-Ready Foodborne Illness Response Strategies 5 76 million illnesses 323,000 hospitalizations 5,000 deaths First comprehensive estimates by CDC since 1987 Used for new cost estimates, risk-assessment, model for other disease estimates Source: Centers for Disease Control and Prevention Epi-Ready Foodborne Illness Response Strategies 6 INTRODUCTION 2 Bacterial Bacillus Brucella Campylobacter Clostridium Escherichia enterohemorrhagic enterotoxigenic Listeria Salmonella Shigella Staphylococcus Streptococcus Vibrio Parasitic Cryptosporidium Cyclospora Giardia Toxoplasma Trichinella Viral Norovirus Rotavirus Astrovirus Hepatitis A Chemical Scombrotoxin Ciguatoxin Mushroom poisoning Heavy metals Source: Centers for Disease Control and Prevention Epi-Ready Foodborne Illness Response Strategies 7 Perceived Etiology of Foodborne Illness among Public Health Personnel The Tennessee Survey Epi-Ready Foodborne Illness Response Strategies 8 Tennessee Survey Percentage of respondents listing it among top 3 causes Est. % of foodborne illness in USA caused by pathogen Pathogen Campylobacter Clostridium perfringens Escherichia coli Giardia lamblia Hepatitis A virus Listeria Norwalk-like virus Salmonella Shigella Staphylococcus Streptococcus Viruses Source: Jones, T.F., Gerber, D.E. Dispatches “Perceived Etiology of Foodborne Illness among Public Health Personnel” http://www.cdc.gov/ncidod/eid/vol7no5/pdf/jones.pdf Epi-Ready Foodborne Illness Response Strategies 9 INTRODUCTION 3 Agent • Recently recognized pathogens • New foodborne modes of transmission Host Environment • Increasing elderly, immunocompromised • New eating habits • Increasing immigration, international travel • Globalization of food supply • Centralization of food processing, large producers Number of Patients Epi-Ready Foodborne Illness Response Strategies 12 11 10 9 8 7 6 5 4 3 2 1 0 Fatal Non-fatal Recall Usual listerosis incubation period Source: Centers for Disease Control and Prevention Plant Construction 6/27 8/2 10 9/6 10/11 11/15 Date 12/20 1/24 2/27 Epi-Ready Foodborne Illness Response Strategies 4/3 11 Source: International Association for Food Protection Epi-Ready Foodborne Illness Response Strategies 12 INTRODUCTION 4 Decide to Investigate? Passive Surveillance YES Outbreak Determination Confirm if Outbreak Occurred? NO YES Outbreak Investigation Laboratory Guidance NO Concluding Actions Epi-Ready Foodborne Illness Response Strategies 13 Epi-Ready Foodborne Illness Response Strategies 14 L y or at r o ab em id Ep io gy lo v En nm iro t en Epi-Ready Foodborne Illness Response Strategies 15 INTRODUCTION 5 Module 1: Passive Surveillance At the end of this module, the participant will be able to: 1. Define “active” and “passive” surveillance systems. 2. Identify potential sources of surveillance data. 3. Name components of a successful surveillance system. 4. Identify reports used to document foodborne illness. 5. Refer complaints to appropriate individual and/or agency. 6. Describe the elements included on an ongoing log of foodborne illness complaints. 7. Define outbreak. 8. List important items of passive surveillance data to review. 9. List reasons whether or not to investigate complaints further. Notification of Illness Obvious outbreaks (go to Module 2 or 3) Refer complaint to responsible person Log complaint Review log and other data for related cases NO Prepare Investigation (go to Module 2 ,3, or 4) YES Decide whether to investigate further *Both laboratory confirmed cases and unconfirmed reports (illness complaints) Illness Have surveillance system in place Module 1: Passive Surveillance* Module 1: Passive Surveillance Task List Illness Review symptomology and onset times for common foodborne illnesses. Utilize recognized information resources for supplemental information. o Control of Communicable Diseases Manual o IAFP documents o www.cdc.gov Health Topics A to Z o FDA Bad Bug Book o MMWR Notification of Illness Use approved forms to document initial reports and gather appropriate information. Each section on the form has a purpose. For obvious outbreaks, record key information on line list and go to Module 2 or 3. Encourage symptomatic clients to submit appropriate clinical specimens. Notify state agencies and other local jurisdictions. Obvious Outbreaks Document all outbreak reports in a foodborne illness complaint log (or equivalent electronic data storage system). Promptly initiate appropriate steps outlined in Modules 2, 3 and/or 4. Identify the information that will need to be gathered during the investigation. Consult with state agencies as needed. Refer To Responsible Person(s) or Agency Refer complaints to the agency with regulatory authority over that facility for collaboration and follow up. Follow-up complaints involving facilities under your jurisdiction. Notify communicable disease staff of outbreaks and reported incidents involving laboratory-confirmed infections. Clearly document referred incidents and what follow up actions were taken. Log Complaint Assign a unique sequential number to each complaint or case investigation. Instruct staff on how to systematically enter data into log. Transfer key information from input forms to log. Establish a retention schedule for surveillance records. Review Log and Other Data for Related Cases Establish a written procedure for reviewing surveillance data. Check baseline data to determine expected levels of health events. Decide Whether to Investigate Further Review the foodborne outbreak definitions. (There needs to be a clear message here.) Review surveillance information to identify what is known and what pieces of information are missing. Review published literature about pathogen (known or suspected) involved. Epi-Ready Passive Surveillance Passive Surveillance Decide to Investigate? NO YES Outbreak Determination Confirm if Outbreak Occurred? YES Outbreak & Epidemiologic Investigation Laboratory Guidance NO Concluding Actions Passive Surveillance 2 Module Learning Objectives Define “active” and “passive” surveillance systems. Identify potential sources of surveillance data. Name components of a successful surveillance system. Identify forms used to document foodborne illness. Refer complaints to appropriate individual and/or agency. Passive Surveillance 3 MODULE 1: PASSIVE SURVEILLANCE 1 Module Learning Objectives (cont.) Describe the elements included on an ongoing log of foodborne illness complaints. Define outbreak. List important items of passive surveillance data to review. List reasons whether or not to investigate complaints further. Passive Surveillance 4 PASSIVE SURVEILLANCE * No Have surveillance system in place Illness Notification of Illness Refer complaint to responsible person Log complaint Review log and other data for related cases Obvious outbreaks Decide whether to investigate further Yes Prepare Investigation * Both laboratory confirmed cases and unconfirmed reports (illness complaints) Passive Surveillance 5 Two Types of Surveillance Active surveillance Passive surveillance Passive Surveillance 6 MODULE 1: PASSIVE SURVEILLANCE 2 Active Surveillance Regular periodic collection of case reports from health care providers or facilities Advantage: data is more accurate than in other types of surveillance Disadvantage: expensive and time consuming Passive Surveillance 7 Passive Surveillance Information provided to the health agency without an initiating action by the agency Required routine reporting by physicians and laboratories Reports from concerned citizens Advantage: less expensive and troublesome to operate Disadvantage: likely to underestimate the presence of disease Passive Surveillance 8 The Surveillance Pyramid Reported to health dept state CDC Culture-confirmed case Lab tests for organism Specimen obtained Person seeks care Person becomes ill Population exposures Source: Centers for Disease Control and Prevention Passive Surveillance 9 MODULE 1: PASSIVE SURVEILLANCE 3 Sources of Foodborne Disease Data Foodborne Outbreak Surveillance System Epidemic Investigations Laboratorybased Surveillance Complaint Investigations Passive Surveillance 10 Infectious Disease Surveillance State public health codes require physicians and laboratories to report certain infectious diseases to public health authorities States report nationally-notifiable diseases to CDC • MMWR Recommendations & Reports, 1997; 46(RR-10) Passive Surveillance 11 Foodborne Classifications of calls to EH at local level Family Alerts Foodborne Outbreaks Isolated Consumer Complaints Different streams of data – local to federal Passive Surveillance 12 MODULE 1: PASSIVE SURVEILLANCE 4 Foodborne Diseases Active Surveillance Network (FoodNet) [15.2% of the U.S. population] Year Pop’n* 1996 14.3 1997 16.1 1998 20.7 1999 25.9 2000 30.5 2001 34.9 2002 38.0 2003 41.5 2004 43.3 2005 44.1 2006 44.9 * in millions Passive Surveillance 13 Incidence* of Selected Foodborne Diseases, United States Healthy People Objectives FoodNet Data Pathogen 1996 1998 2000 2002 2004 2006 2010 Campylobacter 23.5 21.7 15.4 13.3 12.9 12.7 12.3 Salmonella 14.5 12.4 14.2 16.2 14.7 14.8 6.8 E. Coli O157:H7 2.4 2.8 2.0 1.7 0.9 1.3 1.0 Listeria 0.5 0.6 0.34 0.26 0.27 0.31 0.25 * per 100,000 population/year ** estimated, baseline for 2000 objectives Source: Centers for Disease Control and Prevention Passive Surveillance 14 Passive Surveillance 15 MODULE 1: PASSIVE SURVEILLANCE 5 Pathogens Subtyped by PulseNet, United States 1998 1999 2000 2002 E. coli O157:H7 1996 1997 X X X X X X Salmonella X X X X X X Listeria X X X Shigella X X X X Campylobacter Source: Centers for Disease Control and Prevention Passive Surveillance 16 Listeriosis Outbreaks in the United States 1979-2000 PulseNet Year 2000 2000 1999 1999 1998 1994 1989 1985 1983 1979 Vehicle Deli meat Cheese Pate Imported cheese Hot dogs Milk Shrimp Cheese Milk Produce State (10) NC (3) (4) (22) IL CT CA MA MA Source: Centers for Disease Control and Prevention Passive Surveillance 17 Number/100,000 pop. Salmonella Enteritidis Incidence by Region, United States, 1970-99 12 10 8 6 4 2 0 1970 72 74 76 78 80 82 84 86 88 90 92 94 96 98 Year Total New England Mid Atlantic Pacific Other Mountain Source: Centers for Disease Control and Prevention Passive Surveillance 18 MODULE 1: PASSIVE SURVEILLANCE 6 Surveillance System in Place External partners Teams • • • • • • • Epi • Environmental health • Communicable disease nursing • Lab • Health educator Hospitals Clinics Physicians Fire Police Industry Passive Surveillance 19 Networking Share information with other local health departments in region Provide up-to-date list of key contacts in local area Maintain an information flow Passive Surveillance 20 Local Health Dept. Preparation Define roles and responsibilities Have needed supplies on hand Procedures for sharing information (internally and externally) Training plan Periodic meetings Passive Surveillance 21 MODULE 1: PASSIVE SURVEILLANCE 7 Obvious Outbreaks Document all illness reports in a foodborne illness complaint log Initiate appropriate steps during outbreak investigation Identify information needs Notify and consult with appropriate departments (i.e. up the chain of command and horizontally to everyone that may need to know) Passive Surveillance 22 Notification of Illness Symptomatic clients submit clinical specimens Obvious outbreaks record on the line list Use approved forms to document initial reports Passive Surveillance 23 IAFP Forms A, C1 and C2 Passive Surveillance 24 MODULE 1: PASSIVE SURVEILLANCE 8 Refer to Responsible Person or Agency Refer complaints to agency with regulatory authority for collaboration Follow-up complaints under your jurisdiction Notify communicable disease staff of confirmed infections Clearly document referred incidents Passive Surveillance 25 Log Complaint Assign unique sequential number to each complaint Systematically enter data into log Transfer key information from input forms to log Establish retention schedule for surveillance records Passive Surveillance 26 Review Log and Other Data for Related Cases Who’s in charge? Establish written procedure for reviewing surveillance data Check expected levels of health events Passive Surveillance 27 MODULE 1: PASSIVE SURVEILLANCE 9 Outbreak ?? Expected? Norm? Comparisons? Passive Surveillance 28 Outbreak ?? Actionable events are defined locally. Each jurisdiction has to determine whether or not to investigate. CDC and other Federal Agencies have listed the following general definitions as guidance. Passive Surveillance 29 Foodborne Illness Outbreak Definition CDC and IAFP Definition An outbreak is an incident in which two or more persons have the same disease, have similar clinical features, or have the same pathogen thus meeting the case definition - and there is a time, place or person association among these persons. A foodborne outbreak is one that is traceable to ingestion of a contaminated food. Passive Surveillance 30 MODULE 1: PASSIVE SURVEILLANCE 10 Food Emergency Definition (exception to the Outbreak Definition) A single case of suspected botulism, mushroom poisoning, ciguatera or paralytic shellfish poisoning or other rare disease, or a case of a disease that can be definitely related to ingestion of a food, can be considered an incident of foodborne illness and warrants further investigation. Passive Surveillance 31 Determine Whether to Investigate Further Increase in the number of reports over expected Possible epi association (person, place, and time) Possible laboratory linkage Passive Surveillance 32 How to Investigate Further Review surveillance information Review foodborne outbreak definitions Review published literature about pathogen (known or suspected) involved Passive Surveillance 33 MODULE 1: PASSIVE SURVEILLANCE 11 Summary YES Passive Surveillance Decide to Investigate? N O YES Outbreak Determination Confirm if Outbreak Occurred? Outbreak & Epidemiologic Investigation Laboratory Guidance N O Role Passive Surveillance Epi. Receives data from established passive surveillance systems, reviews data, determines the need to investigate further. Lab. Contributes final reports of testing to established passive surveillance systems. Environ. Concluding Actions Receives data from established passive surveillance systems, reviews data, helps determine the need to investigate further. Passive Surveillance 34 Log Book Group Exercise Which of these logged reports would you use your limited resources to investigate further? Why? Passive Surveillance 35 MODULE 1: PASSIVE SURVEILLANCE 12 Module 2: Outbreak Determination At the end of this module, the participant will be able to: 1. List steps needed to prepare for an investigation. 2. Describe actions needed to verify the diagnosis. 3. Identify means for searching for additional cases. 4. List three phases of interviewing. 5. List steps for obtaining a case history. 6. Describe methods for overcoming barriers to interviewing. 7. Describe methods to ensure consistency of interview data. 8. Identify epidemiologic associations. 9. Determine if an outbreak has occurred. Prepare Investigtion Take steps to verify diagnosis Get case history Obtain clinical specimens Collect food samples Develop initial case definition Module 2: Outbreak Determination Make epidemiologic (time, place, person) associations Outbreak Investigation (go to Module 3, 4, 5) YES Determine whether an outbreak occurred NO Generate termination report Module 2 Outbreak Determination Task List Prepare Investigation Share surveillance information with team members and other designated staff. Get appropriate approval from supervisors for planned activities. Gather supplies, equipment, and resources needed to carry out case finding (e.g., forms, equipment, personnel, media spokesperson). Review scientific information regarding known or suspected agents. Notify state agencies and local health departments that may be impacted. Take Steps to Verify Diagnosis Review preliminary information to verify accuracy. Identify what further laboratory analysis or information gathering is needed. Refer to appropriate health care provider or agency with jurisdictional authority. Get Case Histories Establish rapport with the individuals being interviewed. Determine if food samples or clinical specimens are available for testing. Identify if samples will be collected, tested, and who will collect the samples. Fully complete all forms. Ask if individuals have unanswered questions or additional information to share. Thank them for their cooperation. Ensure completed questionnaires, environmental surveys, and other investigation data are turned in to designated person(s). Review for completeness and data quality. Take actions, as needed, to gather missing or incomplete data. Collect Food Samples Take steps to ensure samples are not lost or destroyed. Collect samples using aseptic technique. Hold samples under conditions that maximize usefulness. Determine which tests to request through consultation with laboratory staff. Complete chain of custody, laboratory analysis request and related forms. Obtain Clinical Specimens Ask if the individual is experiencing symptoms or has submitted a stool specimen. Collect specimens following guidance provided by appropriate laboratory. Determine which tests to request. Complete the required paperwork for each specimen. Contact laboratory staff to arrange for testing before sending samples. Search for Additional Cases Activate surveillance network. Inquire about other confirmed or unconfirmed illnesses during patient interview. Make Epidemiologic Associations (Person, Place, Time) Organize key information from cases using a line list or similar document. Summarize data by person, place and time. Systematically review all information and develop initial hypothesis. Determine Whether an Outbreak Occurred Review definitions of a foodborne illness outbreak. Review EH and CD logs for potentially associated cases. Designated LHD staff should determine if an outbreak has occurred. If an outbreak has not occurred, document your conclusions -“Termination report”. Document why a final report was not written. If a foodborne illness outbreak has occurred: Assemble foodborne outbreak team with representatives with known roles and responsibilities in the following areas: • • • • • • Overall team leader Administration Environmental Communicable Disease / Epidemiology Laboratory Media and Public Communications Establish schedule for team meetings. Review all known information with team members. Take immediate actions needed to prevent additional cases. Monitor to determine effectiveness of actions. Proceed to Module 3, 4 and 5 for outbreak investigation. Epi-Ready Outbreak Determination Passive Surveillance Decide to Investigate? YES Outbreak Determination NO Confirm if Outbreak Occurred? YES Outbreak & Epidemiologic Investigation Laboratory Guidance NO Concluding Actions Outbreak Determination 2 Module Learning Objectives List steps needed to prepare for an investigation Describe actions needed to verify the diagnosis Identify means for searching for additional cases List three phases of interviewing List steps for obtaining a case history Outbreak Determination 3 MODULE 2: OUTBREAK DETERMINATION 1 Module Learning Objectives (cont.) Describe methods for overcoming barriers to interviewing Describe methods to ensure consistency of interview data Identify epidemiologic associations Determine if an outbreak has occurred Outbreak Determination 4 Outbreak Determination Flow Diagram Generate termination report Collect food samples Prepare Investigation Take steps to verify diagnosis Obtain clinical specimens Develop initial case definition Make epidemiologic (time, place, person) associations Determine whether an outbreak occurred Get case history Outbreak Investigation Outbreak Determination 5 Prepare Investigation Identify outbreak investigation team Share surveillance information Get appropriate supervisor’s approval Gather supplies and equipment Review scientific information Notify state and local departments • e.g. local state federal Photo courtesy of King County, WA Outbreak Determination 6 MODULE 2: OUTBREAK DETERMINATION 2 When To Activate The Team? Risks and benefits of involving others early on • “The sky is falling!” syndrome • The stealth investigator Begin with the end in mind - what information needs to be gathered? Outbreak Determination 7 Prepare Investigation Goal: each one doing the job they know to do Prior planning • Cannot address every situation • Reduces the number of issues needing to be discussed during the crisis Outbreak Determination 8 Next Steps Verify diagnosis Search for additional cases Determine if cases are associated Outbreak Determination 9 MODULE 2: OUTBREAK DETERMINATION 3 Actions to Verify Diagnosis Review preliminary information Get case history Collect food samples Obtain clinical specimens Appropriate referral to medical care facilities Outbreak Determination 10 Search for Additional Cases Photo courtesy of CDC Activate surveillance network(s) • Health Care Facilities • Laboratories • Exposure Location, if known Inquire during interview • confirmed • unconfirmed Outbreak Determination 11 Get Case History Identify relationship(s) with other cases Ask if still sick Get at least a 72 hour meal history and list of environmental exposures Don’t use forms designed for isolated cases to investigate potential outbreaks Outbreak Determination Photo courtesy of King County, WA 12 MODULE 2: OUTBREAK DETERMINATION 4 Obtaining Demographic, Exposure, and Disease Information All types of investigations require accurate and complete data! Demographic information (age, gender, address, other identifying data) Exposure history (food consumption & environmental exposures) Disease information (symptoms/signs) A good interview is a MUST!!! Outbreak Determination 13 Two Ways to Obtain Information 1.) Written questionnaires 2.) Interviews - in-person - telephone Outbreak Determination 14 Written Questionnaires Can be an alternative to in-person or telephone interviews Limitations • Can have poor response rates • Respondent can misinterpret or fail to understand questions Advantage • Can substantially reduce resources devoted to gathering information, esp. with large outbreaks Outbreak Determination 15 MODULE 2: OUTBREAK DETERMINATION 5 Outbreak Investigation Interviewing Skills Outbreak Determination 16 Interviewing Goals Be consistent in interviews Do your homework to minimize repeat contacts Target questions to greatest degree possible Outbreak Determination 17 Three Phases of Interviewing Before During After Outbreak Determination 18 MODULE 2: OUTBREAK DETERMINATION 6 Before Interviewing Identify objectives • To determine source of illnesses and means of transmission • Minimize repeat interviews Outbreak Determination 19 Before Interviewing (cont.) Identify and prepare interviewers • Assign interviewers; training for all • Arrange work schedules (24/7 work) Assess workload • Number of interviews needed • Types of individuals to interview Select forms to use Outbreak Determination 20 Interviewing Forms Agree on format and content Review new forms with all interviewers Pilot test new forms whenever possible Outbreak Determination 21 MODULE 2: OUTBREAK DETERMINATION 7 Know What You Are After Two purposes: 1.) Generate hypothesis 2.) Test hypothesis Outbreak Determination 22 Generic Interviewing Forms Used for small outbreaks or early in investigation Use same forms - consistency Outbreak Determination 23 Open Ended Questions Data gathering Hypothesis generating Typically used for initial interview Drawback - difficult to analyze statistically Time consuming Outbreak Determination 24 MODULE 2: OUTBREAK DETERMINATION 8 Customized Interviewing Forms Gather specific info after have basic initial info Questions unbiased Order and format of questions can affect answers Outbreak Determination 25 Closed Ended Questions Gather specific information Can be restrictive and leading Can target specific topics Yes______ No_______ Unknown______ Outbreak Determination 26 Closed Ended Questions (cont.) No biased questions No “double barrel” questions Example: “Did you cook and then promptly cool the ground beef”? Outbreak Determination 27 MODULE 2: OUTBREAK DETERMINATION 9 Three Phases of Interviewing Before During After Outbreak Determination 28 During Interviews Establish rapport Identify self, organization, and reason for investigation • Need cooperation to identify source and prevent others from getting sick • Be empathetic Start with easy questions • “Your name/ address/ occupation?” Outbreak Determination 29 During Interviews (cont.) Share at the beginning that during the course of the investigation • Multiple contacts may be needed • Focus of questions may change Outbreak Determination 30 MODULE 2: OUTBREAK DETERMINATION 10 During Interviews (cont.) When they cannot remember meals: ? Ask about food preferences Can rule in / out some foods Identify key days and dates to jog memory (use calendar) Review receipts and/or checkbook Outbreak Determination 31 During Interviews (cont.) Buffets - food items generally not labeled • Need to clearly describe each food People remember better what they ordered from a menu Outbreak Determination 32 During Interviews (cont.) Always provide respondents with an “Other Food” option • Identify “new” previously unidentified food • Double check master food list Other Food ________________ Outbreak Determination 33 MODULE 2: OUTBREAK DETERMINATION 11 During Interviews (cont.) Ask questions as written on form Review form before ending interview Ask if individuals have • Unanswered questions • Additional information Thank them Outbreak Determination 34 Identifying and Overcoming Communication Barriers Cultural diversity Communication styles • Identify communication style of interviewee • Adjust your style to match Last meal bias • Take multi-day food history Outbreak Determination 35 Identifying and Overcoming Communication Barriers (cont.) Irate consumer • Be sensitive, adjust communication style Information often missed • Identify facility locations, extent of exposure, timeline and specific signs and symptoms • Check for food or clinical samples • Consider non-foodborne transmission Commercial food products • Obtain specific dates, locations and product descriptions Outbreak Determination 36 MODULE 2: OUTBREAK DETERMINATION 12 Consider Human Dynamics Anticipate communication barriers • Demographic or cultural factors • Defensiveness Identify appropriate sites and times for interviews • Privacy • Free from distractions Outbreak Determination 37 Diversity Outbreak Determination 38 Assess Communication Styles Action - bottom line / “Just the facts” Feeling - empathetic Creative - need to see the big picture Thinking - want all the details Outbreak Determination 39 MODULE 2: OUTBREAK DETERMINATION 13 The Last Meal Bias Outbreak Determination 40 The Irate Consumer Outbreak Determination 41 Information Often Missed Location of facility (be specific) Example: • “Chain X store in Anytown, USA” • “Chain X store on corner of Main and Fourth in Anytown, USA” Anytown Outbreak Determination X 245 Main St Fourth • “Chain X store located at 245 Main Street in Anytown, USA” Main 42 MODULE 2: OUTBREAK DETERMINATION 14 Information Often Missed (cont.) Extent of exposure (who else ate the food) • Names and contact information of other persons at event • How much did they eat? Outbreak Determination 43 Information Often Missed (cont.) Timeline information • Purchase date/time • Consumption date/time • Symptom onset date/time (for incubation period) Specific signs and symptoms • Especially important if no laboratory confirmation Outbreak Determination 44 Information Often Missed (cont.) Check if food or clinical samples still available Information needed to assess potential for non-foodborne routes of transmission Outbreak Determination 45 MODULE 2: OUTBREAK DETERMINATION 15 Non-Foodborne Routes of Disease Transmission Outbreak Determination 46 The Real Cause of Waterborne E. coli Outbreaks Outbreak Determination 47 Outbreaks Involving Commercial Food Products Purchase dates and locations Product descriptions (labels, lot codes) Outbreak Determination 48 MODULE 2: OUTBREAK DETERMINATION 16 Read the Label: All “Hamburger” Was Not Created Equal Outbreak Determination 49 Restaurants Be as specific as possible How many “combination chicken platters” can there be? Outbreak Determination 50 Three Phases of Interviewing Before During After Outbreak Determination 51 MODULE 2: OUTBREAK DETERMINATION 17 After the Interview Give questionnaires to one key person • Epidemiologist, nurse, clerk, sanitarian • Goal: early identification of inconsistencies Enter information into database ASAP Keep track of • Who has been interviewed • Who is interviewing Outbreak Determination 52 Steps to Ensuring Consistent Data Before the interview During the interview After the interview Outbreak Determination 53 Identify Epidemiologic Associations Summarize Initial Data Descriptive Epidemiology – describes patterns of disease • Person • Place • Time Used to generate hypothesis for further study Outbreak Determination 54 MODULE 2: OUTBREAK DETERMINATION 18 Person: Frequency Tables Distribution of age among all respondents AGE | Freq Percent Cum. -------+-------------------------------0-9 | 4 10.5% 10.5% 10-19 | 5 13.2% 23.7% 20-39 | 12 31.6% 55.3% 40-59 | 10 26.3% 81.6% 60+ | 7 18.4% 100.0% -------+-------------------------------Total 38 100% Outbreak Determination 55 Place: Spot Maps • 10 people who died lived closer to another pump • 5 people who died always sent to pump in Broad Street • 3 people who died were children attending school near the Broad Street pump Dr. John Snow, September 1854 Outbreak Determination 56 Time: Epidemic Curve Outbreak Determination 57 MODULE 2: OUTBREAK DETERMINATION 19 Develop an Initial Case Definition Use descriptive information to develop an initial case definition Outbreak Determination 58 Data to Consider in Developing the Initial Case Definition Person, place and time Laboratory data Environmental data Outbreak Determination 59 Outbreak Determination 60 MODULE 2: OUTBREAK DETERMINATION 20 Summary YES Passive Surveillance Decide to Investigate? YES Outbreak Determination N O Role Outbreak & Epidemiologic Investigation Confirm if Outbreak Occurred? Laboratory Guidance N O Concluding Actions Outbreak Determination Epi. Verifies diagnosis and determines whether cases are associated; searches for additional cases and conducts interviews; determines whether an outbreak has occurred. Lab. Helps verify diagnosis and determine whether cases are associated. Environ. Helps verify diagnosis and determine whether cases are associated; helps search for additional cases; conducts facility interviews and collects samples; can conduct case interviews Outbreak Determination 61 Interview Exercise College Student Interview Outbreak Determination 62 MODULE 2: OUTBREAK DETERMINATION 21 Module 2 Interviewing Group Exercise: A Potential Sorority/ Fraternity Outbreak? Background for the INTERVIEWER: It is Monday morning. You receive a message that a student who attends the local University in your jurisdiction had called with a foodborne complaint. She/he reports that she/he attended a local pizzeria with her/his sorority/fraternity sisters/ brothers Saturday night. Several hours later they developed nausea, vomiting, and diarrhea that lasted throughout the night. Call the student back to collect a case history. You are free to use any tools or interviewing aides that you normally would use to interview this person. Copies of forms are in student handouts. Module 2 Interviewing Group Exercise: A Potential Sorority/ Fraternity Outbreak? Background for the INTERVIEWEE: It is Monday morning. You call and leave a message with the local health department that you, a student who attends the local University, developed diarrhea, nausea and vomiting late Saturday night. You attended a local pizzeria for dinner with your sorority sisters (or fraternity brothers) one of which is also your roommate. You are absolutely positive that the pizza eaten at the pizzeria is what made you sick. After dinner at the pizzeria, you and your sisters/ brothers went to the local bar and consumed numerous alcoholic beverages. Both you and your roommate developed nausea, vomiting (which is rather common for you) and diarrhea sometime between 2 and 4 am early Sunday morning. You also developed fever and chills. You are still feeling sick, which is different than your typical weekend nausea and vomiting. A total of seven sisters/ brothers went to the pizzeria (including you). There is a total of four people ill including you and your roommate. Two more sisters/ brothers became ill last night. You have not gone and will not go to the doctor, especially to provide a stool specimen – that’s gross. Your roommate did go to the University clinic. Another sorority sister/ brother is sick and is thinking of going to the clinic. You can be talked into submitting a stool specimen. You do not want to provide your sisters’/ brothers’ names to the health department. You would be willing to contact your sister/ brothers and have them contact the LHD. All of the sisters/ brothers live on-campus in three different dorms. You have heard that some other people who live in your dorm are sick with the same symptoms. You do not want to provide a 3-day meal history because this is extraneous information and you aren’t really motivated initially to try and remember. You feel that identifying the pizzeria (which also provided bad service) is all that the LHD needs to know. If the interviewer is convincing (cut them some slack) you can be convinced to share that you don’t eat breakfasts (who gets up in time to eat breakfast?), both you and your roommate like to eat lunch at the on-campus cafeteria (usually at the one campus cafeteria deli bar and that dinners that week were at various bars around town. You feel that the LHD nurse is incompetent and you are too busy to answer questions that are unimportant because you already identified what made you ill. Elaborate on this scenario as needed to keep the interview flowing. Feel free to be difficult so that the interviewer can be challenged. Module 2 Interviewing Group Exercise: Interview Evaluation Were these objectives met? Establish Rapport Did the interviewer identify themselves and explain why they were calling? Did they explain why the questions they were asking were important? Did the interviewer address last meal bias and explain that pathogens may take days to cause illness? Purposeful Directed Information Gathering Was the interview structured and “flowing”? Did the interviewer use a data collection form? Did the interviewer explain that they may need to re-contact the case and did they ask when a good time to call back is? Verify Diagnosis Did the interviewer verify the diagnosis by collecting data about symptoms, onset time, medical care etc.? Did the interviewer refer the student for collection of stool specimens? Did the interviewer ask if leftovers were available? Did the interviewer collect a 3-day meal history? Search for Additional Cases Did the interviewer ask about additional cases? Did the interviewer ask about other people who attended the events who were not ill? Look for Person-Place-Time Associations Were person, place, and time association linkages looked for? What else would you want to ask? Module 3: Environmental Assessment At the end of this module, the participant will be able to: 1. Describe/distinguish the difference between environmental assessment (which would include interview and verification), plan review / HACCP inspection, and routine inspection. 2. Describe methods for overcoming barriers to on-site data gathering. 3. List the contributing factors typically associated with foodborne illness. 4. Describe the necessary steps to be covered in the environmental assessment (including steps in pre-visit planning and on-site data gathering). 5. Identify the importance of Contamination, Survival, and Proliferation (CSP). 6. Describe the importance of maintaining key information for the final report. Module 3: Environmental Assessment Task List Planning Before Visiting the Site Determine scope and objective(s) of the site visit. Review available outbreak information (epidemiologic and laboratory findings). Review available facility information Review applicable sections of IAFP manual. Review principles of effective interviewing Gather needed resources On-site Data Gathering Meet with the facility manager(s) and consult with facility staff. Observe applicable food operations Review available records Collect environmental and/or food samples Draw/revise initial flow chart and diagram Implement actions (as needed) to stop the outbreak and/or prevent future reoccurrence. Hazard Analysis Identify the on-site factors that contributed to the outbreak in the following areas: • Contamination • Survival • Proliferation Implement actions (as needed) to stop the outbreak and/or prevent future reoccurrence. Document your findings and immediately share with investigation team members and facility managers (as appropriate). Assemble Team Initial Plan Initial Case Definition Outbreak Investigation Flow Diagram Yes STEP 1: Confirm Outbreak Determine if Outbreak Occurred Make Notifications Initial Hypothesis Refine Hypothesis Outbreak Concluding Actions (Go to Mod. 4) Analyze Data & Interpret Results Outbreak Investigation Flow Diagram Epidemiologic Investigation Refine Case Definition STEP 2: Hypothesis Testing and Analytic Investigation Assign Tasks Laboratory Sample Collection Environmental Assessment Repeat as Necessary Epi-Ready Environmental Assessment YES Decide to Investigate? Passive Surveillance YES Confirm if Outbreak Occurred? Outbreak Determination NO Outbreak Investigation/ Environmental Assessment Laboratory Guidance NO Concluding Actions 2 Outbreak Investigation Flow Diagram STEP 1: Confirm Outbreak Determine if Outbreak Occurred Yes Assemble Team Initial Plan Initial Case Definition Make Notifications Initial Hypothesis 3 MODULE 3: ENVIRONMENTAL ASSESSMENT 1 Outbreak Investigation Flow Diagram STEP 2: Hypothesis Testing and Analytic Investigation Epidemiologic Investigation Assign Tasks Laboratory Sample Collection Refine Case Definition Refine Hypothesis Analyze Data & Interpret Results Outbreak Concluding Actions Environmental Assessment Repeat as Necessary 4 Module Learning Objectives Identify food establishments as dynamic systems Describe the difference between plan review, risk-based inspection, and environmental assessments Identify the contributing factor categories typically associated with foodborne illness • • • Contamination Survival Proliferation 5 Module Learning Objectives (cont.) Describe methods for overcoming barriers to on-site data gathering Describe basic steps of environmental assessments Describe the importance of a well documented final report 6 MODULE 3: ENVIRONMENTAL ASSESSMENT 2 Sources of Foodborne Illness Outbreaks are Varied Restaurants Grocery store delis Church potluck suppers Summer camps Food processors Farms Trucks 7 Dynamic Nature of Food Facilities Food Operations are NOT static Time of Day will be Significant Focus on Processes and Food Flows Production Schedules vs. Prepare to Order Assessing Risk Factors Requires Patience 8 Food Establishments Are Systems Input: Energy or raw material that enters the system Processes: The way input is transformed Output: The product or service that results from the process Feedback: Information that can be used to evaluate and monitor the system SOURCE: EHS-Net 9 MODULE 3: ENVIRONMENTAL ASSESSMENT 3 Food Service Establishment as a System Hold Assemble Reheat Serve Customer Health Internal System Elements People Final Food Item Equipment Cool Customer Satisfaction Profit Process Foods External Feedback to System Economics Ingredients Cook Receive Organisms Chemicals Prep Store & = Inputs & = Processes & = Outputs & = Feedback SOURCE: EHS-Net 10 Partial List of Known Causes of Foodborne Illness Bacterial Bacillus Brucella Campylobacter Clostridium Escherichia enterohemorrhagic enterotoxigenic Listeria Salmonella Shigella Staphylococcus Streptococcus Vibrio Parasitic Cryptosporidium Cyclospora Giardia Toxoplasma Trichinella Viral Norovirus Rotavirus Astrovirus Hepatitis A Chemical Scombrotoxin Ciguatoxin Mushroom poisoning Heavy metals Source: Centers for Disease Control and Prevention 11 Contributing Factors Associated with Foodborne Illness Outbreaks Improper holding temperatures Inadequate cooking Contaminated equipment Unsafe source Poor personal hygiene Cross contamination Photos courtesy of Larry Pong 12 MODULE 3: ENVIRONMENTAL ASSESSMENT 4 Food Safety Management Systems: The Prerequisites Employee Health Personal Hygiene Program Time Temperature Management Cleaning and Sanitizing of Food Contact Surfaces Cross Contamination Prevention Date Marking 13 Every technical food safety issue will ultimately become a human resource issue 14 Process 1: Food Preparation with No Cook Step Receiving Example: Store Prepare Hold Serve Sandwiches w/ RTE Fillings Canned Tuna Canned Chicken Lunch Meat etc. 15 MODULE 3: ENVIRONMENTAL ASSESSMENT 5 Priorities Associated with Process #1 No Cook Step Cold Holding or Time Alone as a Control Food Source (Shellfish; Sashimi) Receiving Temperatures (Tuna; Species of Finfish) Freezing to Destroy Parasites (Fish for Sushi) 16 Process 2: Preparation for Same Day Service Receive Store Prepare Cook Hold Serve Example: Hamburgers 17 Priorities Associated with Process #2 Same Day Service Cooking Hot Holding Time Alone as a Microbial Growth Barrier 18 MODULE 3: ENVIRONMENTAL ASSESSMENT 6 Process 3: Complex Food Preparation Receive Reheat Store Prepare Hot Hold Cook Cool Serve Example: Hot Catered Meal 19 Priorities Associated with Process #3 Complex Food Prep Cooking Hot Holding Time Alone as a Microbial Growth Barrier Cooling Reheating 20 Danger Zone Diagram 21 MODULE 3: ENVIRONMENTAL ASSESSMENT 7 Types of Environmental Activities Plan Review / HACCP • Focuses on FUTURE operations Routine Regulatory Inspection • Focuses on PRESENT operations Environmental Assessment / Food Prep Review • Focuses on PAST operation/event 22 Plan Review & HACCP Evaluate plans and procedures Identify potential problems before they lead to foodborne illness Identify control points to prevent foodborne illness 23 Routine Inspection Emphasis has evolved Old days - legal compliance checklist mentality Currently recommend risk-based inspections to identify cause of foodborne illness 24 MODULE 3: ENVIRONMENTAL ASSESSMENT 8 Conducting Risk-based Inspections I. II. Inspection focus Identify food process categories present III. Establish priorities IV. Determine risk factors in process flows V. Assess active managerial control of risk factors in process flows 25 Environmental Assessment (Food Preparation Review) Definition: A systematic evaluation of food establishments suspected of causing a foodborne illness outbreak. • A cluster of consumer complaints of illness • Lab and/or epidemiological information associated and causative agent identified. Initial agent and vehicle information may be limited. 26 Environmental Assessment / Food Prep Review Objectives Identify foods and beverages offered Reconstruct past events - when food(s) were produced Contributing factors – what happened? • Contamination • Survival • Proliferation Identify environmental antecedents – why did this happen? Implement effective control actions 27 MODULE 3: ENVIRONMENTAL ASSESSMENT 9 Reconstructing Past Events Food Preparation Outbreak Investigation 12 9 6 Service 2 26 27 28 June 29 30 1 2 3 July 4 5 Health Department Notified 28 Example of Systems-Based Investigation Results What happened? • Cutting board and knife used to cut raw chicken were then used to slice carrots for the salad. Why did it happen? • Employee was unaware of the dangers of crosscontamination. What can be done now? • Improve food safety education for employees SOURCE: EHS-Net 29 “When you have a foodborne outbreak, more than one thing went wrong.” Dr. Frank Bryan Centers for Disease Control and Prevention 30 MODULE 3: ENVIRONMENTAL ASSESSMENT 10 C. S. P. Identify Contributing Factors • Contamination • Survival • Proliferation 31 Contamination Photos courtesy of Larry Pong 32 Contamination Receiving, storage, preparation,transport, service Worker hands, ill workers Equipment, utensils Cross-contamination Use of leftovers, returned food 33 MODULE 3: ENVIRONMENTAL ASSESSMENT 11 Survival Ingredients that inhibit growth: acids, salts, preservative Time/temperature abuse Survival on contaminated surfaces, ingredients • Bacteria: spores, toxins • Viruses and parasites Will the agent survive the process? 34 Proliferation Nutrients Availability of oxygen Temperature pH Water activity (aw) Presence of inhibitory substances Microbial interactions Previous stress Time 35 Environmental Assessment Steps Planning Site visit • Interviews • Assessment of food preparation (CSP) Sampling Control strategies 36 MODULE 3: ENVIRONMENTAL ASSESSMENT 12 Planning / Preparation: Review Outbreak Information Review available Epi information: • • • • Dates of onset Incubation period Likely exposure dates/meals For commercial food products – exact product description and purchase dates • Anecdotal information Review food facility information • Existing regulatory records • Menus, recipes, product formulations Review causative agent information • Reservoir • Mode of transmission 37 Knowing the Agent Helps Target Investigation and Control Measures HAZARD Spore-Formers Preformed Toxins (i.e. Clost perf, B cereus, Staph) Related Contributing Factors to Investigate During Field Visit Cooling, Re-Heating, Hot Holding, Bare Hand Contact, Room Temp Storage, Cold Holding Viral Infections (i.e. norovirus) Ill Food Worker, Bare Hand Contact, Handwashing, Contaminated Raw Product Bacterial Infections Ill Food Worker, Bare Hand Contact, Handwashing, Contaminated Raw Product, Cross Contamination, Cooking Parasitic Infections Contaminated Raw Product, Contaminated Source *See IAFP manual for details on specific diseases 38 Differences in Investigation Approaches NO IMPLICATED FOOD: • Cannot focus on a single item in food prep review in the early stages of investigation if no food association established. • Conduct general risk-based assessment using most up to date information available • Determine which samples epi and lab investigators are most interested in (food, clinical, environmental, water/ice) IMPLICATED FOOD: • Food Preparation Review is Key!! 39 MODULE 3: ENVIRONMENTAL ASSESSMENT 13 Other Planning / Preparation Actions Develop initial plan and timetable Assemble materials/personnel • Pre-meetings w/Lab and Epi Be sure your equipment kit is stocked List documents you want to ask for Alert laboratory Alert other agencies 40 Site Visit Manager Interview Facility walk through • Assessment of food preparation Observe operations Sampling Worker interviews Collect records 41 Manager Interviews Explain reason for the investigation Outline investigation objectives Create cooperative relationship 42 MODULE 3: ENVIRONMENTAL ASSESSMENT 14 Manager Interviews (cont.) Food safety knowledge Attitude Credibility of information being provided Photo courtesy of King County, WA 43 Manager Interviews (cont.) Food Worker Health Review health, hygiene and education practices Identify who worked with the implicated food(s) Worker ill during time period of interest? Reconcile with supervisor and coworker recollections Document findings 44 Facility Walk Through Initial facility walk through Measure critical operations before modified Collect samples while available Verify who worked with implicated foods 45 MODULE 3: ENVIRONMENTAL ASSESSMENT 15 Observe Operations- General What process do the foods fit into? • Process 1 – No Cook Step • Process 2 – Same Day Service • Process 3 – Complex Foods What controls are essential for the foods in this process? 46 Observe Operations - Specific How the same items are prepared today Attempt to reconstruct how they were prepared during the time period of interest Take measurements (Time, Temperature Product Dimensions, Locations) Recommend using Food Prep Review Worksheet to systematically gather information 47 Laboratory Testing Samples Food • Disease causing agents • Food characteristics (Ex. pH, water activity) Environmental • Document conditions 48 MODULE 3: ENVIRONMENTAL ASSESSMENT 16 Sampling Issues Plan your approach in advance as much as possible (in consultation with lab) • Type (clinical, food, water, environmental) • Size • Number After reviewing product flow, adjust sampling plan as needed Consider need for sampling to pinpoint contamination source 49 Environmental Sampling Strategies In-line Bracketing Environmental Finished product Consult with lab and federal agencies for proper sampling procedures 50 Environmental Sampling Strategies (cont.) Take environmental samples early in the investigation Have equipment disassembled for environmental swabs Focus on hard-to-clean areas Chain of custody 51 MODULE 3: ENVIRONMENTAL ASSESSMENT 17 Food Worker Interviews Interview without manager present Recommend asking questions in chronological sequence Reconstruct timeline Let them tell their story 52 Food Worker Interviews (cont.) Ask about any unusual circumstances that may have occurred that day--equipment that wasn’t working, short-staffing, someone ill Reword questions when needed, if information isn’t provided or inconsistencies are identified Inconsistent information may indicate sensitive areas. Consider addressing at end of interview 53 When Food Workers Cannot Remember Details Ask about typical work practices and routines Then ask about any unusual events or changes during time period? Remember that outbreaks frequently occur the system was “stressed” 54 MODULE 3: ENVIRONMENTAL ASSESSMENT 18 Concluding the Interviews Ask if individuals have unanswered questions or additional comments • May have information not previously considered • May reveal other useful information Leave your business card for future contact 55 Records & Other Information Sources What SOPs or food safety systems are in place? • • • • • • • HACCP Buyer Specifications/Approved Sources Personal Hygiene Cleaning & Sanitizing Time/Temperature Procedures Recipe Instructions Menu 56 Compile Information Compare information gathered from different sources (env, lab, epi) Level of confidence in information gathered? What is known and what remains unknown? Organize information needed for final report 57 MODULE 3: ENVIRONMENTAL ASSESSMENT 19 Analyze findings - CSP Identify CSP at each step Determine what happened and what did not Interpret: • • • • Laboratory findings Time/temperature curves Food flow diagrams Food preparation reviews/diagrams 58 Diagram the Process - Food Flow Receive Storage Service Preparation Cooking Cold Holding Cooling 59 Tracking Food Flow Through The Facility 60 MODULE 3: ENVIRONMENTAL ASSESSMENT 20 Plot time/temperature curves 61 Precautionary Controls Needed? Take action to prevent additional cases ! 62 Control Actions Immediately stop the outbreak: • • • • • Hold Seize Cease/Desist License Menu Limitation • • • • Embargo Closure Exclusions/ Restrictions Recalls Long term strategies to prevent recurrence: • • • • HACCP Risk Control Plans [“Mini-HACCP”] Training Menu/Supplier/Recipe Modifications 63 MODULE 3: ENVIRONMENTAL ASSESSMENT 21 Write your report Work with other disciplines to complete report and CDC report form, 52.13 Brief narrative Use visual information summaries Contributing factors (“What happened”) – CSP Environmental antecedents – “Why it happened”. 64 Key Resources EHS-Net – see www.cdc.gov Procedures for Investigating Foodborne Illnesses Manual - IAFP 65 Summary YES Passive Surveillance Decide to Investigate? N O Role Outbreak Determination Confirm if Outbreak Occurred? YES Outbreak Investigation/ Environmental Assessment N O Laboratory Guidance Concluding Actions Environmental Assessment Epi. Helps identify suspect facilities, agents and food vehicles; serves as link to medical community, ill people and controls. Lab. Provides guidance on sampling techniques; performs analysis on clinical, environmental and food samples. Environ. Performs environmental assessment; helps implement control measures; serves as link to the food facility. 66 MODULE 3: ENVIRONMENTAL ASSESSMENT 22 EXERCISE Graduation Party Blues Food Preparation Review On Tuesday, July 2, the Health Department was notified that a number of people who attended a catered graduation party on June 29 had developed symptoms compatible with foodborne illness. One hundred and twenty people attended the party; a total of 87 were interviewed, of which 30% were ill. A food specific attack table was constructed and symptoms were listed; see table I and II attached. The duration of illness range from 8 to 72 hours. The incubation period ranged from 8 to 72 hours with the median being 36 hours. Stool samples were negative for Salmonella, Shigella and Campylobacter, however, the Laboratory could not test for E. coli. The following events transpired prior to the graduation party. Mrs. Sanborne was planning a graduation party for her daughter Chaste. She was a little apprehensive about preparing food after all her husband always said she couldn't even make a good cup of coffee. Maybe her neighbor Mrs. Olson could help. Mrs. Olson recommended Kowalski Caterers. She knew Stella Kowalski, the owner. Mrs. Olson and Stella had gone to school together. The graduation party was set for Sunday, June 29. Stella discussed the menu with Mrs. Sanborne and they decided that it would include a chef salad, potato salad, rigatoni with spaghetti sauce, meatballs and sauce and pea salad. Mrs. Olson had agreed to prepare dessert cake and fruit salad. Thursday, June 26 Stella felt better today than she did on Tuesday. She had been running a fever and her head felt like a ton of bricks was resting on it. ''That was one of the bad things about being in business for yourself; you couldn't take a vacation and still get paid. '' She was on her way to Coward's to pick up the frozen meatballs she would be using for the graduation party on Sunday. ''I'll put them in the freezer until tomorrow, then I can start thawing them in the refrigerator. They should be okay.'' Friday, June 27 Stella was feeling her old self again. She picked up the vegetables for the chef salad she was going to make Sunday and she also bought some grapes, watermelon, honey dew, cantaloupes, strawberries, nectarines and apples for her friend Tilly Olson. Tilly was going to prepare fruit salad for the graduation party on Sunday. Frank's market had boxed up all the vegetables and fruits separately for her. Jerry, the owner, selected the fruit for her. He knew what she liked and he was always reliable. Saturday, June 28 It was 7:30 A.M. when Stella arrived at the Kitchen. She liked starting early so she could double-check the list of things to do. Her Kitchen workers, Rita, Lucy and Mary, arrived at 8 A.M. They started to peel the potatoes for potato salad. While they were doing that, Stella started boiling the eggs. When she was finished, she drained the water off and put the unshelled eggs into the refrigerator to cool. All of the peeled potatoes were put into a pot to boil. Next, Rita and Lucy began cutting up all of the vegetables that would go into a salad. When the potatoes were finished boiling, they were taken off the stove and the water was drained to allow them to cool down. It was 10 A.M. The hard- boiled eggs were taken out of the refrigerator. Rita and Lucy shelled the eggs and chopped them up on the cutting board used for the vegetables. The chopped eggs were put into a shallow pan and removed to the refrigerator. Mary removed the pot of boiled potatoes and set it on the bottom shelf of the reach-in to cool down. Mary took out a stainless steel stockpot and put tomato sauce and puree into it. She set it on the stove to cook. As it was cooking, she added some oregano, basil, garlic and onion powder. Next, she removed the meatballs from the refrigerator. They had completely thawed since being put there Thursday. She plated the meatballs into flat bake pans and put them into the oven to bake for about 45 minutes. The sauce was left to cook on the stove. It was around 1 P.M. Rita and Lucy took the potatoes out of the reach-in and chopped them up on the vegetable cutting board. Lucy and Rita had cleaned off all the boards just before lunch with soapy water and then they sprayed them down with the bleach solution Stella made up for them to use. Stella was fussy about keeping things clean. 1 Rita brought out some large stainless mixing bowls while Lucy took the mayonnaise, chopped celery, onions, green peppers and the eggs out the refrigerator. Rita dumped the potatoes in equal portions into each mixing bowl. Lucy added eggs, mayonnaise, celery, onions, green peppers, and vinegar sugar. They mixed the ingredients in both bowls using a large spoon. The mixing bowl contents were transferred with the same spoon into 2-inch deep hotel pans, which were covered with tin foil and put into the reach-in refrigerator. It was 3 P.M. when Mary transferred the cooked meatballs from the preparation table where they had cooled right after she had removed them from the oven. She covered the meatballs loosely with some tin foil. Next, she removed the spaghetti sauce from the stove and left it to cool in the stockpot. Rita chopped up some celery and green onions and then cubed some cheese. She mixed these ingredients in a large bowl, added canned peas, some pimentos, mayonnaise, and ranch dressing. She mixed the ingredients by hand. She emptied the contents of the bowl into 4-inch deep plastic pans, covered them and put them into the reach- in refrigerator. It was 4 P.M. when Mary put the stockpot of spaghetti sauce into the refrigerator to cool. All three left for home. Tilly Olson felt sick all day but she had to prepare fruit salad for Sunday's graduation party. She had her son lift the watermelon out of the refrigerator and onto the counter. She cut the watermelon in half and then cut the fruit out. She then picked out the seeds by hand and diced the fruit. She did the same with the honeydew melons and cantaloupes. She took a break and went to the bathroom, came back and rinsed her hands in the sink. She cored the apples and diced them. She pitted and diced some nectarines. She placed these fruits into the watermelon halves and added strawberries and red and green grapes. Her son helped her lift the finished watermelon boats into the refrigerator. Sunday, June 29 Stella took the van to pick up the fried chickens at Sam and Ella's House of Chicken. She placed several pans of fried chicken into her van. The chicken was placed into insulated hot boxes she had plugged into outlets provided in the van. It was 3:00 P.M. Mary was busy re-heating the spaghetti sauce on the stove that she added all the meatballs to. Lucy was cooking the rigatoni. Mary let the sauce and meatballs cook while she washed the lettuce, which she then placed in clear plastic bags. Stella arrived and began helping them pan out the meatballs, spaghetti sauce and rigatoni into 4-inch hotel pans, which were covered with tin foil and loaded into insulated hot boxes. The covered plastic pans of pea and potato salad were pulled out of the refrigerator and loaded last. It was 5 P.M. and time to deliver all the food. Service was scheduled for 6 P.M. ''All the food looks great thought Mrs. Sanborne. I'm glad that Tilly recommended the caterer and it was nice of her to make up the fruit salad.'' Questions 1-2 1. Using the information provided, complete a food preparation flow diagram for one of the following foods: meatballs, spaghetti sauce, rigatoni, chef salad, fried chicken, potato salad, pea salad and fruit salad. 2. Complete the food preparation review for one of the food items with the attached form. 2 Table I FOOD-SPECFIC ATTACK RATES Food Item ATE THIS FOOD ILL WELL A.R. Potato Salad Chef Salad Pea Salad Fried Chicken Rigatoni Meat Balls French Bread Cake Fruit Salad Wine Punch Peach Schnapps Beer Other 20 20 10 23 24 20 26 22 26 9 4 11 13 32 29 27 45 43 48 40 40 33 14 20 18 36 38.46 40.82 27.03 33.82 35.82 29.41 39.39 35.38 44.07 39.13 16.67 37.93 26.53 DID NOT EAT THIS FOOD ILL WELL A.R. 10 10 20 7 6 10 4 8 4 21 26 19 17 25 28 30 12 14 9 17 17 24 43 37 39 21 CHI2= chi-square test 28.57 26.32 40.00 36.84 30.00 52.63 19.05 32.00 14.29 32.81 41.27 32.76 44.74 CHI2 P= 0.52 0.4705 1.40 0.2364 1.06 0.3028 0.00 1.000 0.05 0.831 2.59 0.107 2.09 0.148 0.00 1.000 6.19 0.012 0.08 0.771 3.63 0.056 0.06 0.810 2.39 0.122 P= Percent Probability Table II SYMPTOMS OF CASES Symptom Number Nausea Weakness Anorexia Headache Diarrhea Abd.Cramps Chills Vomiting Muscle Aches Perspiration Fever Dehydration Other 28 27 27 24 22 22 22 21 18 16 10 2 2 3 Percent 93.33 90.00 90.00 80.00 73.33 73.33 73.33 70.00 60.00 53.33 33.33 6.67 6.67 NOTES 4 FOOD PREPARATION REVIEW Complaint Number: Establishment Name _________________ Address Phone Number ________________ / : AM PM (circle) Date & Time of Suspect Meal mo day yr. Date & Time Food Preparation Started / : AM PM (circle) mo day yr. Person Interviewed Name Position Held: Review Conducted: _______________________ Other (specify) ______________________________________ Suspect Food ___________________________ DATE PROCESS OBSERVATION AMOUNT OF FOOD TIME OF DAY TEMP OF FOOD EQUIPMENT USED 5 DEPTH OF CONTAINER OR FOOD THICKNESS HAND CONTACT WITH FOOD WORKER’S NAME WORKER HEALTH PRIOR TO FOOD PREP Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well SANITATION UNUSUAL EVENTS OTHER INFORMATION 1 Module 4: Epidemiologic Investigation At the end of this module, the participant will be able to: 1. Develop a case definition. 2. Draw an epidemic curve. 3. Develop an initial hypothesis. 4. List three types of study design and a method of statistical analysis. 5. Calculate measures of association. 6. Interpret significance of data. 7. Determine if hypotheses are confirmed or rejected. Yes Notify State Agency Assemble Team Laboratory Sample Collection Repeat as necessary Environmental Assessment * initiate control actions as appropriate Assign Tasks Epidemiologic Investigation Step 2: Hypothesis Testing and Analytic Investigation* Determine whether an outbreak occured Step 1: Confirm Outbreak Refine Case Definition Initial Plan Refine Hypothesis Initial Case Definition Module 4: Epidemiologic Investigation Outbreak Concluding Actions (go to Module 6) Analyze Data and Interpret Results Initial Hypothesis Module 4: Epidemiologic Investigation Task List Develop an Initial Case Definition and Hypothesis Develop initial case definitions to be used to determine if an individual is an outbreak-associated case. Classify cases in categories based on the certainty of diagnosis. (Definite/Confirmed, Probable/Presumptive, Possible/Suspect) Revise and make definitions more specific as new information is received. Plot cases on an epidemic curve. Develop/revise hypotheses. Analyze Data and Test Hypotheses Determine study design and method of statistical analysis. • Cohort • Case-control Interview identified cases and controls. Determine if analysis will be done by hand or using computer. If computer is used, initiate measures to ensure accurate and timely data entry. Describe extent of outbreak by person, place and time (descriptive analysis). • Epidemic curves • Frequency tables • Spot maps Calculate measures of association. • Cohort study – Relative Risk based on attack rates • Case-control - Odds Ratio based on odds Interpret results. Determine if hypotheses are confirmed or rejected. • If no association found, develop new hypotheses and identify information needed to test new hypotheses. • Reanalyze data or gather additional information needed to test new hypotheses. Organize analyses in preparation for final report and CDC 52.13 form. Epi-Ready Epidemiologic Investigation YES Passive Surveillance Decide to Investigate? YES Outbreak Determination NO Confirm if Outbreak Occurred? Outbreak & Epidemiologic Investigation Laboratory Guidance NO Concluding Actions Epidemiologic Investigation 2 Module Learning Objectives Develop a case definition Draw an epidemic curve Develop an initial hypothesis List three types of study design and a method of statistical analysis Epidemiologic Investigation 3 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 1 Module Learning Objectives (cont.) Calculate measures of association Interpret significance of data Determine if hypotheses are confirmed or rejected Epidemiologic Investigation 4 Develop an Initial Case Definition: Counting Apples and Oranges Set of criteria for deciding whether an individual should be classified as “ill” Objective criteria Outbreak-associated vs. normal background • Value of routine surveillance data • Primary vs. secondary cases Epidemiologic Investigation 5 Case Definitions Begin general - become increasingly specific as information is gathered • Person, place and time association • Clinical criteria • Classify cases based on certainty Definite/Confirmed Probable/Presumptive Possible/Suspect Epidemiologic Investigation 6 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 2 Revise Case Definitions Ongoing throughout investigation Precise definitions reduce potential for misclassification • Estimated 36% of enteric infections are foodborne • Incomplete case history can haunt you • Incorrectly classifying individuals can bias results • Make it harder to detect true associations Epidemiologic Investigation 7 Make Epidemiologic Associations Person, Place, Time Systematically organize key information Develop initial hypothesis Epidemiologic Investigation 8 Person: Frequency Tables Distribution of age among all respondents AGE | Freq Percent Cum. ------+----------------------21 | 1 2.9% 2.9% 22 | 2 5.7% 8.6% 23 | 4 11.4% 20.0% 24 | 3 8.6% 28.6% 25 | 3 8.6% 37.1% 26 | 2 5.7% 42.9% 27 | 3 8.6% 51.4% 28 | 2 5.7% 57.1% 29 | 1 2.9% 60.0% 30 | 1 2.9% 62.9% 33 | 1 2.9% 65.7% 34 | 3 8.6% 74.3% 35 | 5 14.3% 88.6% 36 | 1 2.9% 91.4% 37 | 2 5.7% 97.1% 39 | 1 2.9% 100.0% ------+----------------------Total| 35 100.0% Epidemiologic Investigation 9 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 3 Place: Spot Maps • 10 people who died lived closer to another pump • 5 people who died always sent to pump in Broad Street • 3 people who died were children attending school near the Broad Street pump Dr. John Snow, September 1854 Epidemiologic Investigation 10 Place: Common Exposure Location Examples • • • • Case 1 – rest. A, B, C, D Case 2 – rest. B, E, F Case 3 – rest. A, B, G, H, I Case 4 – rest. B, D, J, K Epidemiologic Investigation 11 Place: Common Exposure Location (cont.) Same restaurant Multiple restaurants, same chain or owner Multiple chains, common distributor Epidemiologic Investigation 12 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 4 Time: Frequency Table Incubation time (in hours) among those who were ill Current selection: TIMESYMPTO>0 INCUBATION | Freq Percent Cum. -----------+----------------------------------------10.0 | 1 7.1% 7.1% 11.0 | 1 7.1% 14.3% 24.0 | 7 50.0% 64.3% 25.0 | 2 14.3% 78.6% 26.0 | 2 14.3% 92.9% 34.0 | 1 7.1% 100.0% -----------+-----------------------------------------Total | 14 100.0% Epidemiologic Investigation 13 Symptoms: Frequency Table Frequency of vomiting among those who were ill Current selection: ILL="Y" VOMITING | Freq Percent Cum. ---------+-----------------------------------+ | 3 21.4% 21.4% | 11 78.6% 100.0% ---------+-----------------------------------Total | 14 100.0% Epidemiologic Investigation 14 Number of Patients An Epidemic Curve 12 11 10 9 8 7 6 5 4 3 2 1 0 Fatal Non-fatal 6/27 8/2 9/6 10/11 11/15 Date 12/20 1/24 2/27 4/3 Source: Centers for Disease Control and Prevention Epidemiologic Investigation 15 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 5 Number of Cases Point-Source Exposure 12 11 10 9 8 7 6 5 4 3 2 1 0 1 3 5 7 9 11 13 15 Days Epidemiologic Investigation 16 Number of Cases Ongoing Exposure 12 11 10 9 8 7 6 5 4 3 2 1 0 1 3 5 7 9 11 13 15 Days Epidemiologic Investigation 17 Number of Cases Secondary Exposures 12 11 10 9 8 7 6 5 4 3 2 1 0 1 3 5 7 9 11 13 15 Days Epidemiologic Investigation 18 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 6 Hypothesis “An unproved theory ...tentatively accepted to explain certain facts or to provide a basis for further investigation” Source: Webster’s New World Dictionary, 3rd Edition Photo courtesy of CDC Epidemiologic Investigation 19 Example of Hypothesis Potato salad consumed at the Smith wedding reception caused illnesses Data needed to test information • Who ate potato salad? • How much did each eat? • Illness onset (date and time)? Epidemiologic Investigation 20 Develop Initial Hypothesis Multiple hypotheses may be compatible with data initially Helps clarify • What is known • What is missing • Actions needed to gather missing information Epidemiologic Investigation 21 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 7 When the Causative Agent is Unknown Review what is known about cases • Symptoms, severity of disease • Events attended or anything unusual • Foods consumed and methods of food preparation Identify most likely agent(s) • Review references • Consultation Epidemiologic Investigation 22 Known Causative Agent Review what is known about the agent • Typical signs and symptoms • Modes of transmission • Foods in past outbreaks Is this situation similar to other reported incidents? © Dennis Kunkel Microscopy, Inc. Epidemiologic Investigation 23 New Routes of Transmission are Being Identified E. coli O157:H7 in apple cider Epidemiologic Investigation 24 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 8 Case Definition vs. Hypothesis Hypothesis Case Definition • • • • Person Place Time Symptoms • Theory Describes exposure to test analytically Classifies cases vs. controls Do NOT include hypothesis in case definition!!! Epidemiologic Investigation 25 Group Exercise Case Definition and Hypothesis Are “cases” associated? Epidemiologic Investigation 26 Epidemiologic Investigation Determine study design • Case Series • Cohort • Case- Control Epidemiologic Investigation 27 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 9 Case Series Appropriate to use if: • Small number of cases (< 5) • Controls are unavailable (e.g.,everyone ill) Provide person, place, and time associations Epidemiologic Investigation 28 Cohort Studies Groups of exposed and unexposed individuals can be easily identified Compare risk of illness by what was/was not eaten Example: church supper Epidemiologic Investigation 29 Case-Control Studies Typically used in foodborne investigations when: • Exposed group is very large or • Exposed group is not easily identified Compare ill with non-ill individuals to determine likelihood of having eaten specific foods Examples: very large wedding reception or sporadic E. coli cases Epidemiologic Investigation 30 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 10 Measures of Association Between Exposure (Food Item) and Disease Selection of measure depends on type of study • “Relative risk” cohort studies Risk of developing disease given the exposure • “Odds ratio” case-control studies Odds of having the exposure given the disease Computer programs greatly speed the calculations Epidemiologic Investigation 31 Attack Rate: Measure of Occurrence Attack Rate (AR) • Expresses occurrence of a disease among a particular at-risk population for a limited period of time, often due to a very specific exposure. • Can be event-specific or food-specific AR = Number ill people who consumed item Total number people consuming item Epidemiologic Investigation 32 Estimating Risks Associated with “Exposure” Compare attack rates among exposed and unexposed Relative Risk = Attack Rate (exposed) / Attack Rate (unexposed) Epidemiologic Investigation 33 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 11 Using the 2 by 2 Table to Calculate Relative Risk Estimates magnitude of association between exposure and disease in exposed relative to group unexposed group Disease Yes ( + ) Yes ( + ) No ( - ) total a b a+b Exposure No ( - ) c d c+d total a+c b+d a+b+c+d RR = 1 RR < 1 RR > 1 a / (a + b) RR= c / (c + d) No Association Negative Association Positive Association Epidemiologic Investigation 34 Epidemiologic Investigation 35 Church Supper Cohort Study – Relative Risk Vanilla ice cream • AR (exposed) ÷ AR (unexposed) 79.6 ÷ 14.3 = 5.6 • Persons consuming vanilla ice cream 5.6 times more likely to become ill than those who did not eat vanilla ice cream Epidemiologic Investigation 36 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 12 Church Supper Cohort Study – Relative Risk Chocolate ice cream • AR (exposed) ÷ AR (unexposed) 53.2 ÷ 74.1 = 0.7 • Persons consuming chocolate ice cream were 0.7 times as likely to become ill than those who did not eat chocolate ice cream Epidemiologic Investigation 37 Using the 2 by 2 Table to Calculate Odds Ratio Estimates magnitude of association between exposure and disease in diseased relative to non-diseased group (cases) group (control) Disease Yes ( + ) Yes ( + ) No ( - ) total a b a+b Exposure No ( - ) c d c+d total a+c b+d a+b+c+d OR = 1 OR < 1 OR > 1 = ad OR = ab /c /d bc No Association Negative Association Positive Association Epidemiologic Investigation 38 Odds Ratio from Case-Control Studies Measurement of the odds of having an exposure (specific food consumption) given the disease Estimates the Relative Risk derived from cohort studies Odds Ratio Odds of exposure among cases = Odds of exposure among controls = (OR) Epidemiologic Investigation a/c b/d = ad bc 39 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 13 How Valid are Your Findings? Is the observed association between exposure and disease due to alternative explanations? Bias: systematic error (selection, information {recall, interviewer, misclassification}) Chance: sampling variability and sampling size Epidemiologic Investigation 40 Examples of Bias Random misclassification of cases vs. controls or exposed vs. unexposed • categories of persons less “clean” • biases OR or RR toward “1” Recall bias • cases better remember exposures than do controls • problem with retrospective studies • may result in inflated OR Epidemiologic Investigation 41 Evaluating the Role of Chance P value • Probability a given association could have occurred by chance alone • “Statistically significant” defined as p ≤ 0.05 • Consider all available evidence when interpreting P values 95% Confidence Interval • Range within which the true association lies, based on 95% assurance Epidemiologic Investigation 42 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 14 P Values and Confidence Intervals, Example 1 Table 16 Analysis of Food Item 2 ILL ITEM2 | + - | Total -----------+---------------+-----+ | 5 10 | 15 - | 9 11 | 20 -----------+---------------+-----Total | 14 21 | 35 5 / (5 + 10) RR= 9 / (9 + 11) = .3333 .45 RR= 0.74 95% confidence limits for RR 0.43 < RR < 2.79 Uncorrected P-value = 0.486 Epidemiologic Investigation 43 P Values and Confidence Intervals, Example 2 Table 15 Analysis of Food Item 1 ILL ITEM1 | + - | Total -----------+---------------+-----+ | 11 4 | 15 - | 3 17 | 20 -----------+---------------+-----Total | 14 21 | 35 11 / (11 + 4) RR= 3 / (3 + 17) = .7333 .15 RR= 4.89 95% confidence limits for RR 1.65 < RR < 14.50 Uncorrected P-value = 0.000490 Epidemiologic Investigation 44 P Values and Confidence Intervals, Example 2 (cont.) Relative Risk (Outcome:ILL=+; Exposure:ITEM1=+) 4.89 95% confidence limits for RR 1.65 < RR < 14.50 Indicates that best estimate of increased risk of illness associated with consumption of food item 1 is 4.89 times; however, we are 95% confident that the true risk ratio is no less than 1.65 and no greater than 14.5 times the risk of those not consuming this item. (Lack of inclusion of 1.0 in this interval demonstrates a significantly positive association) Epidemiologic Investigation 45 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 15 P Value: Effect of Sample Size Disease Exposure + - Total + 4 1 5 - 1 2 3 5 3 8 Fisher’s Exact P value = .46 OR = 8/1 = 8 Epidemiologic Investigation 46 P Value: Effect of Sample Size (cont.) Disease Exposure + - Total + 8 2 10 - 2 4 6 10 6 16 Fisher’s Exact P value = .12 OR = 32/4 = 8 Epidemiologic Investigation 47 P Value: Effect of Sample Size (cont.) Disease Exposure + - Total + 12 3 15 - 3 6 9 15 9 24 Fisher’s Exact P value = .04 OR = 72/9 = 8 Epidemiologic Investigation 48 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 16 Statistical Summary • RR is calculated in cohort studies. • RR compares rate of illness in exposed group to rate of illness in unexposed group. • OR is calculated in case-control studies. • OR = odds in favor of exposure among cases compared to the odds in favor of exposure among the controls. • RR and OR are both measures of association. • “Not Significant” ≠ “No Association” No significance may reflect lack of association, but may also reflect a study size too small to detect true association. Epidemiologic Investigation 49 Take Home Message If RR or OR = 1, or if the 95 % CI includes 1 then the result is not considered statistically significant (i.e. there is no statistical difference between the groups). If RR or OR is less than 1 may mean food item is “protective”. The lower the p-value the more unlikely the results are due to chance alone. Epidemiologic Investigation 50 True Story 4 friends meet for dinner • 3 eat chicken fried rice • 1 chop suey 3 ill with vomiting & diarrhea 12-18 hrs. after meal; all 3 ate fried rice No samples available for testing Time temperature abuse of fried rice documented P value = 0.25 Is this a foodborne outbreak? Epidemiologic Investigation 51 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 17 Interpret Results Hypotheses confirmed or rejected? • If rejected, develop new hypotheses • Test new hypotheses by: More analysis with existing data Gather and analyze new data Final conclusions • Was it foodborne? Epidemiologic Investigation 52 Summary YES Passive Surveillance Decide to Investigate? Outbreak Determination N O Role Confirm if YES Outbreak Occurred? Outbreak & Epidemiologic Investigation N O Laboratory Guidance Concluding Actions Epidemiologic Investigation Epi. Develops case definition and hypotheses; performs descriptive and analytic analyses of outbreak Lab. Helps identify agent and establish case definition; contributes to epidemiologic associations Environ. Helps identify agent and establish case definition; contributes to epidemiologic associations Epidemiologic Investigation 53 Statistics Exercise Joe’s Thanksgiving Dinner Epidemiologic Investigation 54 MODULE 4: EPIDEMIOLOGIC INVESTIGATION 18 Module 4 Case Definition and Hypothesis Exercise Instructions: Practice developing case definitions and hypothesis by answering the questions after reading the scenarios. It is Monday morning. You have two messages on your answering machine concerning potential foodborne illnesses. The first involves a husband, wife, and the second an unrelated female. All reported that they became “ill” within the last 24 hours. The couple both experienced vomiting and diarrhea beginning around 2:00 a.m. Monday morning and claim that the dinner served to them at a Sunday afternoon church function caused them to be ill. The unrelated female experienced severe diarrhea and nausea beginning around 10:30 p.m. Sunday night and claims that the dinner she ate on Sunday night at Kermit’s Kafe caused her to be ill. 1. Is it time to activate the foodborne illness team? If not, what information needs to be gathered before doing so? You call the three cases back and collect a three-day meal history. You find out that all three cases ate breakfast Friday morning at Becker’s Breakfast Bar. At the bar, they had four foods in common: scrambled eggs, bacon, fruit salad, and white toast. Throughout the day on Monday, you receive calls from four more people with foodborne-related complaints. All of the cases ate at Becker’s Breakfast Bar on the previous Friday. You find that all seven cases ate scrambled eggs and bacon. While all seven of the cases had experienced diarrhea, some also had additional symptoms. Four had experienced vomiting, four had nausea, and three had abdominal cramps. Fortunately for you, three of the cases are still having diarrhea and have agreed to provide a stool specimen. In addition, two cases have leftover bacon & eggs in their refrigerator, which you will arrange to have tested at your regional laboratory. By this time, you have alerted your supervisor to the situation and he/she has activated the outbreak team. 2. Develop a case definition for this outbreak. How many people fit the case definition? Environmental health completes their investigation of the food facility on Monday afternoon. They discovered that the carton of eggs used last Friday had been left out at room temperature, uncracked, on a counter Thursday night before being used Friday morning. The other foods appeared to be properly handled and stored. EH collected the food from the case’s homes and sent it to the lab to be analyzed. They also discovered that several employees had been sick with mild diarrhea throughout last week. Two sick employees agreed to submit samples for lab analysis. All ill employees are restricted from work until they are symptom free. So far, no new reports have come in from additional cases. Your outbreak team meets briefly to discuss the new information. 3. What alternative hypotheses do you have about the cause of this outbreak? Meanwhile, the personal health unit received a call from another person (a friend of one of the other cases) who heard that something was going on and wanted to report that he was also sick after eating at Becker’s. However, his illness wasn’t that bad and he only had nausea and abdominal cramps. His food history revealed that he had a bagel, although he did have a bite of his friend’s eggs. The outbreak team meets again at the end of the day to discuss the new information. 4. Does this person meet the current case definition? 5. Any changes in case definition or hypotheses? On Wednesday morning, the lab results have come back on all of the collected food and stool specimens. All food samples tested negative for bacterial pathogens while the stool samples (three customers and two food workers) tested positive for norovirus (norwalk-like virus). No new reports of foodborne illness have come to the health department. 6. Develop a final case definition for this outbreak (definite, probable, possible cases)? 7. How many people are in each category? Module 4 Group Exercise: Joe’s Thanksgiving Dinner OUTBREAK EXERCISE THE SETTING The day is the Monday after Thanksgiving. You have just returned from a weekend with your family, when your friend Joe calls you. He is upset, and hopes that your public health experience can help him. He tells you that he had a Thanksgiving dinner on Thursday for many of the students still in town. During the weekend, over half of the people who attended the party got ill, experiencing fever, diarrhea, and vomiting. While it may have just been the flu, Joe suspects their illness may be a result of something he served at the dinner. He asks you to find out what happened. First, you ask him about the dinner itself. Joe tells you that preparation for the dinner started Wednesday night, when he made several pumpkin pies. The pies included both milk and eggs in the filling. (This filling would be considered a type of custard.) After baking them, he left them on the counter to cool. They stayed on the counter until dinner on Thursday, although the recipe said to put the pies in the refrigerator after they had cooled. On Wednesday night, Joe also took the turkey out of the freezer and left it on his counter to defrost. Because of the late night of baking, Joe overslept Thursday morning. He expected guests to start coming at 1:00, and realized that if he baked the turkey at the temperature suggested, it could not get done on time. He decided to turn up the temperature on the oven assuming that the additional temperature would make up for less baking time. While the turkey was baking he went out to buy milk. When he returned he set down the bag with the milk in it to speak to a friend calling on the telephone to ask what he could bring to dinner. Joe forgot to put the milk in the refrigerator until he noticed it several hours later as he was passing by the table. He pulled the turkey out of the oven at 12:30. It looked brown, and felt hot throughout. He made gravy from the turkey drippings, and served it over potatoes. He then warmed up some beans that had been homecanned for him by his mother. The dinner started at 1:00 when the guests ate. Along with the turkey, potatoes, gravy, milk, and beans, Joe also served a gelatin salad and biscuits. People helped themselves to the pies on the counter all afternoon. Having learned the characteristics of the dinner, you then wanted to learn more about the people attending the dinner. You ask Joe for the names of the people who came to the party. You give these people a call on the phone, and ask them a list of questions including their experiences of illness since the party (symptoms, time of onset), what they ate at the party, when they ate, and whether they saw a doctor about their illness. Some of the data collected is attached to this exercise. Your objective is to use this data to characterize the outbreak. You can approach this exercise as a foodborne disease outbreak. Module 4 Group Exercise: Joe’s Thanksgiving Dinner OUTBREAK EXERCISE Subject Sex Ill 1 F Y 2 F Y 3 F Y 4 M Y 5 M Y 6 F Y 7 M Y 8 F Y 9 10 11 12 13 14 15 TOTAL M M M F M M F Y N N N N N N Onset Sx Time Friday 2am Friday 10am Friday 5pm Friday 5pm Friday 2pm Friday 3pm Friday 3pm Friday 11pm Friday 7pm Beans Gravy Milk Turkey Pie Vomiting Diarrhea Fever N N N Y N Y Y N Y Y N Y Y Y Y N Y N N Y N Y Y Y Y Y Y Y N Y Y Y Y Y Y Y Y Y Y Y Y Y N Y Y Y Y N N N N Y N N Y Y Y Y Y Y N Y Y Y Y N Y Y Y Y Y 12 Y N Y Y N Y Y 10 N N Y N Y N Y 6 N N N N Y N Y 10 Y Y N Y Y N Y 8 N N N N N N N 7 N N N N N N N 8 Y N N N N N N 6 Module 4 Group Exercise: Joe’s Thanksgiving Dinner OUTBREAK EXERCISE Purpose: You are to determine which food served at Joe’s Thanksgiving dinner caused the foodborne outbreak. Use the mathematical concepts taught in Module 3 to determine if there is a statistical association between a given exposure and onset of illness. Instructions: Read the information regarding the background setting of the outbreak. Then combine into groups to go through the exercise. Please answer the following questions in order after reading the notes section. Notes: A 2x2 table is frequently used to summarize data to show the relationship between a specific food exposure and subsequent onset of disease. Each case or control is categorized into one of the four cells in the table. Disease Yes Exposure No Yes a b No c d a= the number of individuals who are exposed and have the disease b= the number who are exposed and do not have the disease c= the number who are not exposed and have the disease d= the number who are not exposed and do not have disease An attack rate (AR) is the proportion of people in a well-defined population that develop the illness of interest during a limited time period. The greater the difference between attack rates for those exposed and those not exposed to a particular food the higher the probability that the food item caused the illness outbreak. AR exposed = a/(a+b) AR unexposed = c/(c+d) AR exposed - AR unexposed = Risk Difference The relative risk (RR) is another way of comparing attack rates among exposed and unexposed persons. Use RR to measure the association between exposure and disease in a cohort study. RR= a/(a+b) c/(c+d) The odds ratio (OR) also estimates the magnitude of an association between exposure and disease but is used in case-control studies. The math calculation is slightly different because you are calculating the odds that someone is at risk of developing disease given an exposure in an unknown population instead of the rate of disease development in an exposed known population such as in a cohort study. OR= a/c = ad b/d bc Questions: 1. What type of a study would you perform in Joe’s case in order to determine which food caused the illness? Why? 2. What is the attack rate of people who ate turkey that developed vomiting? Diarrhea? Fever? Vomiting: Diarrhea: Fever: 3. Fill in the 2x2 table for people who ate pie and became ill. Disease Yes Exposure to Pie No Yes No 4. Fill in the 2x2 table for people who ate turkey and became ill. Disease Yes Exposure to Turkey No Yes No 5. Calculate the relative risk for developing disease if the subject ate pie. What does this value mean? 6. Calculate the relative risk for developing disease if the subject ate Turkey. What does this value mean? 7. Which food item was more likely to cause illness- the Turkey or the pie? Why? 8. The p-value for the relative risk of the turkey is p=0.03. What does this mean? What if the p value is p=.65? Module 5: Laboratory Guidance At the end of this module, the participant will be able to: 1. Determine criteria for testing 2. List key items found in a sample kit 3. Describe the collection of food samples 4. Name the reason for using a chain of custody document 5. Describe the collection of clinical specimens from cases Module 5: Laboratory Guidance Task List Coordinate sampling and analysis strategy with the team and appropriate laboratory prior to sampling. Collect leftovers of implicated foods under suspicion. Collect original food product from the suspect facility. Collect individual ingredients if complete food product is unavailable. Collect clinical specimens from ill cases. Notify appropriate laboratory as to arrival of specimens. Submit specimens to the laboratory. Identify what to test to request for a given sample. Epi-Ready Laboratory Guidance Passive Surveillance Decide to Investigate? NO YES Outbreak Determination Confirm if Outbreak Occurred? YES Outbreak & Epidemiologic Investigation Laboratory Guidance NO Concluding Actions Laboratory Guidance 2 Module Learning Objectives Determine criteria for testing List key items found in a sample kit Describe the collection of food samples Name the reason for using a chain of custody document Describe the collection of clinical specimens from cases Laboratory Guidance 3 MODULE 5: LABORATORY GUIDANCE 1 Decision to Test? Tests performed determined by local health department foodborne illness investigation team Preliminary epidemiological associations required prior to submitting specimens • Laboratory will examine the most likely suspect foods first Laboratory Guidance 4 Criteria To Determine Testing To Be Performed Summary of predominant symptoms Time interval Duration of symptoms Results of prior testing Communicate with lab and tell them what they are testing for Laboratory Guidance 5 Signs and Symptoms Upper Gastrointestinal Neurological pathogen C. botulinum Ciguatera Scombroid Shellfish toxin (PSP) Mushrooms Chemicals incubation 12-72h 2-6h 1min-3h 30min-3h <2h-8h min-hours (nausea & vomiting) duration days-mos days-mos 3-6h days indefinite indefinite Lower Gastrointestinal (cramps & diarrhea) pathogen incubation B. cereus [Diarrheal] 10-16h Campylobacter spp. 2-5 days C. perfringens 8-16h E. coli 0157:H7 1-8 days others 1-3 days Salmonella spp. 1-3 days Shigella spp. 24-48h Vibrio cholerae 24-72h parahaemolyticus 2-48h Yersinia spp. 24-48h Giardia lamblia 1-2 weeks Laboratory Guidance pathogen B. cereus [Emetic] S. aureus Chemicals Norovirus incubation 1-6 h 1-6 h minutes-hours 12-48 hours duration 24 h 24-48h ? hours Generalized Illness (fever, chills, sweating, malaise) duration 24-48h 2-10 days 24-48h 5-10days 3-7 days+ 4-7 days 4-7 days 3-7 days 2-5 days 1-3 weeks days-weeks pathogen incubation Streptococcus spp. 1-3 days Brucella abortus 7-21days L. monocytogenes 9-48 h/ 2-6 weeks Salmonella typhi 7-28 days Vibrio vulnificus 1-7 days Hepatitis A 15-50 days Hepatitis E 15-65 days Cryptosporidium parvum 2-10 days Cyclospora spp. 1-14 days Anisakis ~2 weeks Trichinella 1-2 days / 2-8 weeks Toxoplasmosis spp. 5-23 days duration weeks weeks weeks weeks 2-8 days weeks-months weeks-months weeks-months weeks-months 3 weeks months months 6 MODULE 5: LABORATORY GUIDANCE 2 Types of Illness Infection--illness from ingestion of the organism present in a food product • • • • • • • • Salmonella spp. Shigella spp. Campylobacter spp. Listeria monocytogenes Yersinia spp. Hepatitis A Norovirus Vibrio spp. Campylobacter jejuni courtesy of CDC Laboratory Guidance 7 Types of Illness Intoxication-illness from ingestion of pre-formed toxin present in the food product • C. botulinum 1,2 • B. cereus (emetic form) 1,2 • Staphylococcus aureus 2 Clostridium botulinum courtesy of CDC 1 Spore former 2 Toxin producer Laboratory Guidance 8 Types of Illness Toxin mediated infection-illness from ingestion of organism in a food product followed by toxin production in the body (toxin is not present in the food) • C. perfringens • B. cereus (diarrheal) • E. coli O157:H7 E. coli courtesy of CDC Laboratory Guidance 9 MODULE 5: LABORATORY GUIDANCE 3 Types of Illness Naturally occurring chemical toxins present in the food product • Scombrotoxin • Ciguatoxin Photo courtesy of USDA Laboratory Guidance 10 Interpreting Results Quantitated pathogens • S. aureus • B. cereus • C. perfringens Reported as Colony Forming Units/gram or ml of food Laboratory Guidance 11 Interpreting Results (cont) Enriched pathogens • • • • Salmonella Vibrio Listeria etc. Reported as Found (Isolated)/Not Found (Not Isolated) Laboratory Guidance 12 MODULE 5: LABORATORY GUIDANCE 4 Review References Control of Communicable Diseases Manual Procedures to Investigate Foodborne Illness Diagnosis and Management of Foodborne Illnesses Laboratory Guidance 13 Additional Considerations Some foodborne illness investigations will have the causative agent determined by epidemiological means. © Dennis Kunkel Microscopy, Inc. Laboratory Guidance 14 Submitting Concerns Submit stool and food specimens according to the laboratory procedures and protocols Vomitus may be an unsatisfactory specimen for foodborne illness testing • Check with the testing laboratory regarding the suitability of this specimen Laboratory Guidance 15 MODULE 5: LABORATORY GUIDANCE 5 Sampling Kit Laboratory Guidance 16 Collecting Food Samples Always ask if food is still available • At food facility • At home Photo courtesy of CDC Commercially processed foods • Identity Product description Processor information Lot numbers, expiration dates, use-by dates • Integrity (intact packaging preferred) Laboratory Guidance 17 Sample Collection All food items should be collected • As soon as an outbreak is suspected • Using aseptic techniques, including sterile implements Laboratory Guidance 18 MODULE 5: LABORATORY GUIDANCE 6 Sampling a Solid Food Item Whenever possible, submit in original container 100 to 500 grams For large items, using sterile utensils, take representative sample Transport in sterile, leak-proof container Hold under refrigeration until transported Transport to the lab on wet ice Laboratory Guidance 19 Sampling a Solid Food Item Laboratory Guidance 20 Notice fat content Laboratory Guidance 21 MODULE 5: LABORATORY GUIDANCE 7 Sampling of a Liquid Product Whenever possible, submit in original container Stir or shake liquid to ensure sample is homogeneous If too large to shake, take multiple samples Pour or ladle liquid into leak-proof container Hold under refrigeration until transported Transport to the lab on wet ice Laboratory Guidance 22 Special Points in Food Sampling Official samples vs. unofficial samples Take samples early in investigation Maintain chain of custody Equipment disassembly for environmental swabs Focus on hard-to-clean areas Photo courtesy of Larry Pong Laboratory Guidance 23 Food Sampling Scenario Visit and evaluate facility Collect food samples still on hand Laboratory Guidance 24 MODULE 5: LABORATORY GUIDANCE 8 Food Sampling Label the samples themselves Laboratory Guidance 25 Food Sampling Keep written records Laboratory Guidance 26 Food Sampling Consult with lab staff Arrange for receipt of sample(s) Appropriate tests Laboratory Guidance 27 MODULE 5: LABORATORY GUIDANCE 9 Chain of Custody Each person signing the form is responsible for the care and preservation of that sample while in their possession Form will account for all persons handling the sample • • • • Who obtained Who delivered Who tested Who disposed Those signing may be called on to testify in a criminal proceeding Laboratory Guidance 28 Chain of Custody Chronological written record • Acquisition until final disposition • Assures continuous accountability Considered confidential/classified Maintained in a secure location Laboratory Guidance 29 Chain of Custody Each chain of custody form is agency specific • If a sample is transferred to a second agency that agency will start another chain of custody form for the time that the sample remains in its custody • Each agency is responsible for retaining records regarding sample Laboratory Guidance 30 MODULE 5: LABORATORY GUIDANCE 10 Collecting the Clinical Specimen Fecal specimens • Do not pass directly into tube • Pass specimen into clean, dry container that can be discarded • Follow directions included with transport medium • Submit to lab Include proper paperwork required by the laboratory Ship according to current regulations Laboratory Guidance 31 Collecting the Clinical Specimen Laboratory Guidance 32 Summary YES Passive Surveillance Decide to Investigate? N O Role YES Outbreak Determination Confirm if Outbreak Occurred? Outbreak & Epidemiologic Investigation Laboratory Guidance N O Concluding Actions Laboratory Guidance Epi. Investigation determines most likely agent(s) and food(s). Lab testing is driven by this information. Lab. Performs testing of clinical specimens and food samples, confirms suspected agent(s) and food(s) Environ. Performs environmental assessment of facility, collects food samples for testing, and contributes to epi investigation. Laboratory Guidance 33 MODULE 5: LABORATORY GUIDANCE 11 *Toxin-mediated infections still result from the ingestion of the organism. The distinction is that the organism produces a toxin in the gut which causes illness – most often diarrhea. No toxin is produced in the food. C. perfringens1 B. cereus (Diarrheal)1 E. Coli 0157:H7 Toxin-Mediated Infections* Hepatitis A Norovirus Vibrio Infection – (illness from ingesting the organism) Salmonella Campylobacter Listeria Yersinia Shigella Trichinella Anisakis 1 – Spore Former 2 – Toxin Producer Intoxication- (illness from toxin formed in the food) C. botulinum1-2 B. cereus (Emetic) 1-2 Staphylococcus2 Other- (naturally occurring chemical toxins) Scombrotoxin Ciguatoxin Neurological duration 24 h 24-48h ? Upper Gastrointestinal* incubation 1-6 h 1-6 h minutes-hours (nausea & vomiting) pathogen B. cereus [Emetic] Staph aureus Chemicals Norovirus 12-48 hours hours ** *May involve other symptoms, especially diarrhea Flu Mimicking*** duration days-mos days-mos 3-6h days forever? forever? Lower Gastrointestinal* * (fever, chills, sweating, etc.) pathogen incubation C. botulinum 12-72h Ciguatera 2-6h Scombroid 1min-3h Shellfish toxin (PSP) 30min-3h Mushrooms <2h-8h Chemicals min-hours (cramps & diarrhea) incubation duration pathogen incubation duration pathogen B. cereus [Diarrheal] 10-16h 24-48h Streptococcus 1-3 days weeks Campylobacter 2-5 days 2-10 days Brucella abortus 7-21days weeks C. Perfringens 8-16h 24-48h Listeria 9-48 h/ 2-6 weeks weeks E. coli 0157:H7 1-8 days 5-10days Salmonella typhi 7-28 days weeks others 1-3 days 3-7 days+ Vibrio vulnificus 1-7 days 2-8 days Salmonella 1-3 days 4-7 days Hepatitis A 15-50 days weeks-months Shigella 24-48h 4-7 days Hepatitis E 15-65 days weeks-months Vibrio cholerae 24-72h 3-7 days Cryptosporidium 2-10 days weeks-months parahaemolyticus 2-48h 2-5 days Cyclospora 1-14 days weeks-months Yersinia 24-48h 1-3 weeks Anisakis ~2 weeks 3 weeks Giardia 1-2 weeks days-weeks Trichinella 1-2 days / 2-8 weeks months Toxoplasmosis 5-23 days months **May involve other symptoms – esp. vomit, fever, ***May not include all symptoms, such as fever. Note that “Flu” is a respiratory illness unrelated to foods! but diarrhea is pronounced. Control Measures • Approved Source – Freezing to -4oF for 7 days or -31oF for 15 hours • Usually not practical to do this in a retail or food service facility – Fishing from Ciguatera-free waters – Temperature Control to prevent Scombroid • Control from the time of catch to the time of service • Preventing Cross-Contamination – Separating RTE from raw – Cleaning and sanitizing equipment and food contact surfaces • Personal Hygiene Control – Employee Health – Handwashing – No Bare Hand Contact with RTE Food Chicken Ground Beef Pork Fish • Cooking – – – – • Hot Holding • Cooling Control Measures 165oF for 15 seconds 155oF for 15 seconds 145oF for 15 second 145oF for 15 second 135oF or above – 135oF to 41oF in 6 hours….provided that… – 135oF to 70oF in 2 hours • Reheating – 165oF for 15 seconds within 2 hours SUGGESTED KIT FOR COLLECTING SAMPLES DURING AN INVESTIGATION OF A FOODBORNE OUTBREAK Equipment Containers, screw-cap, single use Water sample bottles (bacteriological) Water sample bottles (partial chemical) Whirl paks 6"x9" or similar size Large plastic bags that can be sealed Ice paks Styrofoam cooler Pipettes* Spatulas* Scoops, 1 tbsp in size* Swab material w/ transport container Gloves, nitrile or latex, medium size Aluminum foil Tongs* Metal stem thermometer or thermocouple Chain of custody forms or documentation protocol IAFP "Procedures to Investigate Foodborne Illness" manual Field investigation forms, rec. forms from IAFP manual or equivalent Requisition forms for samples sub to regional labs Cardboard box(es) Treatment Sealed, sterilized Sterilized, containing sodium thiosulfate, mailers In mailers Sterilized Sterilized Liquid/solid food specimens Coliform water sampling Nitrate water sampling or solid/liquid samples Solid foods Transport/cooling specimens Frozen, may be reusable Intact, unused Sterilized, individually wrapped Sterilized, individually wrapped Sterilized, individually wrapped Sterilized, individually wrapped Sterilized, individually wrapped Sterilized or from unopened container Sterilized, individually wrapped In protective case, sanitized before use --------------- Legal purposes --------------- Reference Material --------------- Investigation/record keeping --------------- Laboratory submission of specimens Shipment of specimens for analysis Shipment of specimens for analysis Labeling of samples Sanitize thermometer Securing packaging around samples Sealing shipping containers Guidance --------------- Shipping labels --------------- Waterproof permanent markers Alcohol swabs Rubber bands ------------------------------------------- Tape, waterproof Food sampling directions ----------------------------- *Items that may be single use. Purpose Cooling/preservation Transport/cooling specimens Liquid sampling Solid sampling Solid/Liquid sampling collect surface samples Sampling/handling of large food items Wrapping large solid food items Solid sampling Measure food temperatures SOURCES Materials for Foodborne Disease Investigation Kits International BioProducts, Inc. P.O. Box 2728 Redmond, WA 98073 1-800-729-7611 Thomas Scientific 99 High Hill Road @ I-295 P.O. Box 99 Swedesboro, NJ 08085 1-800-345-2100 VWR Scientific 800 E. Fabyan Pkwy Batavia, IL 60510 1-8000-932-5000 Cole Parmer 325 E. Bunker Court Vernon Hills, IL 60061-1844 1-800-323-4340 Fisher Scientific 1600W. Glenlake Ave. Itasca, IL 60143 1-800-766-7000 Weber Scientific 2732 Kuser Road Hamilton, NJ 08691 1-800-328-8378 Gempler’s 100 Countryside Dr. P.O. Box 270 Belleville, WI 53508 1-800-382-8473 NASCO 901 Janesville Ave. Fort Atkinson, WI 53538-0901 1-800-558-9595 Lab Safety Supply Inc. P.O. Box 1368 Janesville, WI 53547-1368 1-800-356-0783 Ben Meadows Company 3589 Broad Street Atlanta, GA 30341 1-800-241-6401 All QA Products, Inc 3427 SW 42nd Way Gainesville, FL 32608 1-800-845-8818 Omega One Omega Drive P.O. Box 4047 1-800-826-6342 Module 6: Concluding Actions At the end of this module, the participant will be able to: 1. Describe the need to inform the public. 2. Identify control strategies that need to be implemented. 3. Document the results of the outbreak investigation. 4. Describe means for using investigative data for prevention. 5. Explain the importance of an after action group review to improve coordination and action in the future. Analyze Data and Interpret Results (Module 3) Inform Public Implement Control Strategies Prepare Final written repot and CDC form 52.13 Module 6: Outbreak Concluding Actions Use investigative Data for prevention Module 6: Outbreak Concluding Actions Task List Implement Control Strategies Initiate or finalize control strategies to prevent additional cases of foodborne illness. Identify method(s) of assessing compliance with control measures. Coordinate actions with state and federal agencies when multiple jurisdictions are involved. Inform Public Determine if there is an ongoing public health threat. Alert the public to both the potential hazard and methods of reducing risks. Keep records for future reference. Write Final Report & Submit CDC 52.13 Prepare final written report. Complete CDC form 52.13 if necessary Use Investigative Data for Prevention Hold investigation team meeting to review investigation and findings. Identify risk factors that caused or contributed to the outbreak. Determine the extent of high-risk practices. Develop a plan to reduce risk factors. Communicate findings to those who can put them into practice. Hold investigation team meeting to review outbreak investigation process. Develop recommendations for improving future outbreak investigations. Epi-Ready Concluding Actions Passive Surveillance Decide to Investigate? YES NO Outbreak Determination Confirm if Outbreak Occurred? YES Outbreak & Epidemiologic Investigation Laboratory Guidance NO Concluding Actions Concluding Actions 2 Module Learning Objectives Describe the need to inform the public Identify control strategies that need to be implemented Document the results of the outbreak investigation Describe means for using investigative data for prevention Explain the importance of an after action group review to improve coordination and action in the future Concluding Actions 3 MODULE 6: CONCLUDING ACTIONS 1 Concluding Actions Implement Control Strategies Analyze Data and Interpret Results Prepare Final Written Report and CDC form 52.13 Use Investigative Data for Prevention Inform Business/Public Concluding Actions 4 Concluding Actions Putting the pieces together Feedback Concluding Actions 5 Implement Control Strategies Strategies to prevent further illness/exposure Assess compliance Coordinate with other affected agencies Concluding Actions 6 MODULE 6: CONCLUDING ACTIONS 2 Examples of Regulatory Tools Hold Seize Embargo Cease/desist License/menu limitation Closure Exclusions /restrictions Recalls Concluding Actions 7 Inform the Public Public’s right to know: Inform the public if an ongoing threat exists Population susceptibility Concluding Actions 8 Risk Communication Public announcement must: Explain potential risk Provide measures to reduce risk Concluding Actions 9 MODULE 6: CONCLUDING ACTIONS 3 Using the Records We Keep Epidemiological Environmental Laboratory Public Health Nursing Concluding Actions 10 Report Writing If you don’t clearly communicate your findings, no one benefits from all of your hard work. “A job isn’t complete until the paperwork is done.” Concluding Actions 11 Do’s of Report Writing Gather each discipline’s summary Be short and to the point Include attacks rates, frequencies and epi curve Include information requested in CDC eFORS form 52.13 Concluding Actions 12 MODULE 6: CONCLUDING ACTIONS 4 Do’s of Report Writing Gather each discipline’s summary Be short and to the point Include attacks rates, frequencies and epi curve Include information requested in CDC eFORS form (52.13) Concluding Actions 13 Report Writing Concluding Actions 14 Final Report Format 1. 2. 3. 4. 5. Cover Page Summary Description of Outbreak Introduction/Background Methods- environmental, epidemiology & laboratory 6. Results- environmental, epidemiology & laboratory 7. Discussion ry l gy to 8. Recommendations lo ta ra o io en b m a m 9. Acknowledgements e L on id Ep v ir 10. Appendices En Concluding Actions 15 MODULE 6: CONCLUDING ACTIONS 5 Cover Page Unique name of outbreak Date of outbreak Place of outbreak Agencies involved in investigation Author(s) of report Concluding Actions 16 Summary Basic Epi information – who, where, when & what Environmental findings Laboratory results Actions taken for resolution Lessons learned Recommendations Concluding Actions 17 Introduction & Background Brief introduction about the place of outbreak Background surveillance Similar outbreaks in the past Specific information about the facility – restaurant, convention center, school etc. Concluding Actions 18 MODULE 6: CONCLUDING ACTIONS 6 Description of Outbreak How was the outbreak detected? Subsequent actions – initial response to the outbreak Initial control measures Any collaborations (FDA, USDA, CDC…) Media Concluding Actions 19 Methods: Environmental Evaluation of facility and personnel Food preparation review Food flow diagram Food sources (labels, tags, invoices) Samples collected Contributing Factors Concluding Actions 20 Methods: Epidemiology Descriptive Epidemiology Hypothesis Type of study – case control, cohort etc. Definitions – case, control etc. Statistics – software, description of statistical test used. Specimen(s) collected Concluding Actions 21 MODULE 6: CONCLUDING ACTIONS 7 Methods: Laboratory Food samples – descriptions of types, contents Specimens – stool, urine, blood etc. Type of tests conducted – culture, PFGE etc. Concluding Actions 22 Results: Environmental Results of Inspection Actions taken - follow up inspection, closure of restaurant Training Contributing Factors Concluding Actions 23 Results: Epidemiology Descriptive Epidemiology – details Analytical Epidemiology Tables – Epi curve, food attack rate table etc. Details of statistical analysis Concluding Actions 24 MODULE 6: CONCLUDING ACTIONS 8 Results: Laboratory Food samples Specimens – stool, urine, blood etc. Interpretation of results © Dennis Kunkel Microscopy, Inc. Concluding Actions 25 Discussion Hypothesis accepted/rejected: Strength of association • Magnitude of odds ratio or relative risk Consistency of data • Internally (this investigation) • Externally (with other investigations) Temporality (cause precedes effect) Concluding Actions 26 Discussion (cont’d) Biologic plausibility Dose-response relationship • Example: Consistent increase in attack rate as number of servings consumed increases Coherence with known (published) information about the disease Experimental evidence Concluding Actions 27 MODULE 6: CONCLUDING ACTIONS 9 Discussion (cont’d) Study limitations Control measures Lessons learned Concluding Actions 28 Recommendations Education of employees Education of community Preventive measures to avoid reoccurrence Follow up actions Concluding Actions 29 Acknowledgements Outbreak team Collaborative people, organizations Community Concluding Actions 30 MODULE 6: CONCLUDING ACTIONS 10 Appendices Statistical tables Correspondence Educational material Media related items Publications (references) Concluding Actions 31 CDC eFORS form 52.13 Concluding Actions 32 Use Investigative Data for Prevention Hold team meeting to debrief • What went right • What could have been improved Surveillance Investigation Prevention and education Concluding Actions 33 MODULE 6: CONCLUDING ACTIONS 11 Team Investigation Debriefing Develops useful foodborne disease data bank Useful in the event of litigation Reinforces necessity and success of teamwork approach Reliable, complete information provides ability to determine foodborne disease trends, incidence and causal factors Concluding Actions 34 Team Investigation Debriefing (cont.) Essential for detecting and evaluating new foodborne disease hazards and risks Allows for preparation of public report outlining investigation findings Establishes good community relations Concluding Actions 35 Summary A successful outbreak investigation involves a systematic approach relying on disciplines to operate as a T.E.A.M where: Together Everyone Achieves More Concluding Actions 36 MODULE 6: CONCLUDING ACTIONS 12 Summary YES Passive Surveillance YES Outbreak Determination Decide to Investigate? N O Confirm if Outbreak Occurred? Outbreak & Epidemiologic Investigation Laboratory Guidance N O Concluding Actions Role Concluding Actions Epi. Prepares final report; provides summary of descriptive epi. and data analysis; utilizes results of the investigation to prevent future outbreaks; informs public. Lab. Prepares final report; provides summary of samples, analysis and results. Environ. Prepares final report; provides summary of environ. assessment; enforces control measures and utilizes results of the investigation to prevent future outbreaks. Concluding Actions 37 MODULE 6: CONCLUDING ACTIONS 13 OUTBREAK REPORT TEMPLATE Outline 1) Cover Page 2) Summary (abstract) 3) Introduction and Background 4) Description of outbreak 5) Methods – Environmental, Epidemiology, Laboratory 6) Results – Environmental, Epidemiology, Laboratory 7) Discussion 8) Recommendation 9) Appendices 10) Acknowledgements Details Cover Page: 1) Unique name of Outbreak 2) Name of person submitting report 3) Date of Outbreak (Time period) 4) Agencies involved in outbreak investigation 5) County, District (if that is not included in the "unique name") Summary: 1) Basic Epi Info – who, where, when and what 2) Environmental findings 3) Lab results 4) Actions taken for resolution of problem. 5) Lessons learnt and recommendations made to prevent reoccurrence Introduction and background: 1) Brief introduction about the place (city, town etc.) and population. 2) Background surveillance, endemic disease? 3) Similar outbreaks in the past. 4) Specific information about the facility i.e. restaurant type, convention center etc. 1 Description of outbreak: 1) How was the outbreak detected? (Who got the initial call)? 2) Subsequent actions – response to confirm the outbreak (hypothesis generating interviews, getting in touch with hospitals, clinics, contacts etc.) 3) Initial control measures initiated 4) Any collaboration (USDA etc.), media management, if any. Methods Environmental: 1) Evaluation of affected facility and personnel 2) Samples collected. 3) Food preparation review 4) Any Trace back required Epidemiology: 1) Epi description – who, where, when and what. 2) Hypothesis. 3) Case and control definition. 4) Specimens collected. 5) Analyses done - software used, study type (Case control, cohort study etc.) Type of statistics (e.g. chi square etc.) 6) Risk factors Laboratory: 1) Food samples and specimens (description of type and contents). 2) Type of tests done (Bacterial culture, EIA, PFGE etc.) Results Environmental: 1) Critical and non-critical violations. 2) Action taken (downgrading). 3) Follow up Inspection. Epidemiology: 1) Details (description) of cases and controls 2) Foods implicated 3) Epi curve, other tabulations (attack rate table etc.) 4) Results of statistical analysis. 2 Laboratory: 1) Results of food samples and specimen testing (include molecular type results etc.) 2) Interpretation. Discussion: 1) 2) 3) 4) Hypothesis accepted/rejected and reasons (epidemiological, statistical etc.) Study Limitations. Control measures taken and results. Lessons learnt for outbreak team. Recommendations: 1) Education of employees, employees put on sick leave. 2) Community education 3) Means to prevent future outbreaks. 4) Any follow up action. Appendices: 1) Questionnaire 2) Statistical tables 3) Educational material used etc. 4) Letters sent to Participants, physicians etc. 5) Any media related items (press release, newspaper stories) 6) Publications. Acknowledgements: 1) Outbreak team 2) Collaborative members (USDA, university, hospital etc.) 3) Community members. Note: 1) 2) 3) 4) 5) Method to be devised to de-identify personal information (HIPPA). Secure storage of reports. Retention schedule. Disposal at the end of retention schedule. Appropriate use of outbreaks reports for educational purposes. 3 EXAMPLE REPORT Maple Rapids Church Youth Group Program Campylobacter jejuni Outbreak Investigation Report Maple Rapids Clinton County, Michigan Date of Incident: October 29, 2003 Number of Ill Persons: 6 Prepared by: Mid-Michigan District Health Department Norm Keon, Epidemiologist December 23, 2003 EXAMPLE REPORT Introduction: On Wednesday, November 12th, a public health nurse at our Gratiot Branch Office was notified by a physician’s assistant (PA) from a family practice in Alma that they were treating an eleven year old girl who had laboratory confirmed Campylobacter jejuni. The girl claimed that other children in her church were also ill with similar symptoms and that they had all attended a meeting of their youth group on Wednesday, October 29th. They had been practicing for a play and were served a snack at that gathering. It was the PA’s belief that an outbreak had occurred in this group and he was alerting the local health department to this possibility. Environmental: Methods: No environmental health actions were taken in response to this outbreak. Our CD nurse requested information from the mother of the index case concerning what foods were served at the meeting. Results: It was determined that a limited number of foods were served. They consisted of cinnamon rolls, frosting, and milk. However, a relative of one of the mothers had supplied the milk from their dairy farm and it was unpasteurized. Since we were notified fourteen days after this event there was no milk available for testing. Epidemiology: Case finding: Our communicable disease nurse notified our medical director and epidemiologist. She also contacted the mother of the index case and obtained additional information about the youth group from her. The mother reported that approximately eight children were ill. Our epidemiologist notified the Disease Control office at the Michigan Department of Community Health (MDCH) that we had an outbreak of campylobacter possibly related to raw milk consumption and would be submitting stool specimens. The name of the outbreak was “Maple Rapids Church.” A line listing was started based on information provided by the mother of the index case. Questionnaire/Analysis: A questionnaire was designed, and a database was created utilizing Epi-Info. The questionnaire was delivered to the mother of one of the ill girls who served as the supervisor for the group of children. She had agreed to distribute it at their next meeting. Case definition: A case was defined as any person who attended the October 29th meeting of the youth group and within 2 to 5 days subsequently experienced vomiting and/or diarrhea. 2 EXAMPLE REPORT Results: Descriptive Analysis (Note: since we had limited completion of our questionnaires, some of this data has been abstracted from information provided by informants) Persons attending the meeting: 20 (approx.) Persons who completed a questionnaire: 5 (25%) Ill persons who met the case definition: 6 Attack rate among those attending: 30 % Age: Range 8 - 41 Mean 15.2 Median 11.0 Sex: Female 83 % Male 17 % Symptom frequencies and percentages: Diarrhea 6 100 % Bloody stools 2 9% Vomiting 4 67 % Cramps 6 100 % Fever 3 50 % (Mean 102 deg.) Chills 2 33 % Headache 4 67 % Nausea 5 83 % Soreness 1 17 % Sought medical care: Hospitalized: 3 0 50 % 0% Incubation period (hours): Range 33.5 – 74.5 Mean 60.8 Median 67.5 Duration of illness (days): Range 2.5 – 8.0 Mean 5.2 Median 5.0 Statistical Analysis Due to the low response rate of completed questionnaires it was not possible to conduct two-way table analyses for the individual food items. 3 EXAMPLE REPORT Laboratory: Methods: Stool examination was completed at the Gratiot Community Hospital laboratory for the index case. Our CD nurse, after consulting with our epidemiologist, requested that several other persons who had been ill submit specimens to the State Laboratory at MDCH. She provided stool collection kits to four persons with mailing instructions. None were submitted. However, a sample from one child was sent by her physician to the Sparrow Hospital Laboratory. Results: The following line list summarizes the laboratory findings for the two children mentioned above. Age/Sex Lab 11yo/M GCH 11yo/F Sparrow Onset Date 11/01 10/31 Date Collected Results 11/07 Positive for C. jejuni 11/17 Positive for C. jejuni Conclusions: We gathered illness and exposure data (of varying completeness) on nine individuals who attended a church youth group meeting. Two children had stool specimens positive for Campylobacter jejuni. This organism has a reservoir in animals, particularly cattle and poultry. That fact, combined with the fact that few other food items were served in addition to the raw cow milk, lends validity to our hypothesis that this outbreak was caused by the ingestion of the raw milk. However, since all of the milk was either drank or disposed of we had no samples to test. Due to the lack of complete epidemiological data we were unable to determine if there was a dose-response relationship evident with milk consumption. We received poor cooperation from this group of people in completing the questionnaires and in submitting stool specimens. A possible explanation was the religious orientation of these families and their possible distrust of government. Recommendations: We advised the youth group supervisor and several other mothers during our contacts with them that the consumption of raw milk is a confirmed risk for the acquisition of a number of zoonotic diseases of public health importance and that we do not recommend this practice. 4 Number of Cases 6 5 4 3 2 1 0 27 30 31 1 2 November 3 4 Maple Rapids Church Youth Group Program Campylobacter Outbreak Onset of Illness by Date Maple Rapids (Clinton County) -- Oct/Nov 2003 29 Youth Group Meeting 5:30pm 28 October EXAMPLE REPORT Cases Campylobacter+ Cases EXAMPLE REPORT EXAMPLE REPORT FORM APPROVED OMB NO.0920-0004 CDC USE ONLY INVESTIGATION OF A FOODBORNE OUTBREAK __ __–__ __ __ __ __ __ This form is used to report foodborne disease outbreak investigations to CDC. A foodborne outbreak is defined as the occurrence of two or more cases of a similar illness resulting from the ingestion of a common food in the United States. This form has two parts: Part 1 asks for the minimum data needed and Part 2 asks for additional information. For this investigation to be counted in the CDC annual summary, Part 1 must be completed. We encourage you to complete as much of Part 1 and Part 2 as you can. STATE USE ONLY ____________________ Part 1: Required Information 1. Location of Exposure: 2. Dates: 3. Numbers of Cases Exposed: Date first case became ill: State: MI Multi-state exposure _1 0__ / _3_ _1_ / _2_ _0_ _0_ _3_ Month Day Year Date of first known exposure: _1_ _0_ / _2_ _9__ / _2_ _0_ _0_ _3_ County: _Clinton_______ Multi-county exposure Month List other states/counties in Comments, bottom of this page Day Year Date of last known exposure: _1_ _0_ / _2_ _9_ / _2_ _0_ _0_ _3_ Month Day Lab-confirmed cases: Probable cases: __2__ (A) __4__ (B) Estimated total ill: _____ (If greater than sum of A+B) Year Please send epidemic curve, if available. 4. Approximate Percentage of Total Cases in Each Age Group: percent of total cases) <1 year: _____% 20-49 yrs: _17__% 1-4 yrs: _____% 6. Investigation Methods: (Check all that apply) 5. Sex: (Estimated ⌧ Interviews of cases only Case-control study Cohort study Food preparation review Food product traceback Male: __17_ % > 50 yrs: _____% Female: __83_ % 5-19 yrs:__83_% 7. Implicated Food(s): (based on Reasons listed in Item 15 on page 3) Factory or production plant Source investigation (farm, marine estuary, etc.) Environment / food sample cultures 8. Etiology: (Name the bacteria, virus, parasite, or toxin. Include specific details on toxin or ______Raw milk_____________ organism, such as phage type, virulence factors, molecular fingerprinting, antibiogram, metabolic profile. Criteria for confirmed etiologies are defined in MMWR 1996 / Vol. 45 / ss-5 / Appendix B.) ___________________________ Etiology Serotype (if avail.) Campylobacter jejuni ___________________________ ___________________________ ___________________________ Etiology undetermined More than one etiology (Please list in Comments) Could not be determined Isolated/identified from (check all that apply): ⌧ Patient specimen(s) Food specimen(s) Environment specimen(s) Food worker specimen(s) 9. Contributing Factors: (See list on page 2, check all that apply) 10. Agency reporting this outbreak: Contributing factors unknown Contamination Factor: C1 C2 C3 C10 C11 C12 Mid-Michigan District Health Dept.__________ Contact Person: C4 C5 C13 C14 ⌧C6 P11 ⌧ P12 (describe in Comments) ⌧C7 C8 C15 (describe in Comments) Proliferation/Amplification Factor (bacterial outbreaks only): P1 P2 P3 P4 P5 P6 P10 Other Characteristics P7 P8 C9 N/A P9 N/A Survival Factor (microbial outbreaks only): S1 S2 S3 S4 ⌧ S5 (describe in Comments) __Norm Keon______________________ TITLE: ___Epidemiologist __________________ PHONE NO: _989-831-5237 FAX NO: ___989-831-5522 E-MAIL: [email protected] _______________ ______________ _______ Date of completion of this form: N/A Was food-worker implicated as the source of contamination? Yes If yes, please check only one of following: laboratory and epidemiologic evidence epidemiologic evidence (w/o lab confirmation) lab evidence (w/o epidemiologic confirmation) prior experience makes this the likely source (please explain in Comments) NAME: No _1_ _2_ / _ 2_ _3__ / _2_ _0_ _0_ _3_ Month Day Year Initial Report Updated Report ⌧ Final Report Additional data suggests this is not a foodborne outbreak Comments: ________________________________________________________________________________________________ Page 1 CDC 52.13 REV. 8/1999 EXAMPLE REPORT FORM APPROVED OMB NO.0920-0004 This questionnaire is authorized by law (Public Health Service Act, 42 USC §241). Although response to the questions asked is voluntary, cooperation of the patient is necessary for the study and control of disease. Public reporting burden for this collection of information is estimated to average 15 minutes per response. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to PHS Reports Clearance Officer; Rm 721-H, Humphrey Bg; 200 Independence Ave. SW; Washington, DC 20201; ATTN: PRA, and to the Office of Information and Regulatory Affairs, Office of Management and Budget, Washington, DC 20503. The following codes are to be used to fill out Part 1 (question 9) and Part 2 (question 15). 1 Contamination Factors: C1 - Toxic substance part of tissue (e.g., ciguatera) C2 - Poisonous substance intentionally added (e.g., cyanide or phenolphthalein added to cause illness) C3 - Poisonous or physical substance accidentally/incidentally added (e.g., sanitizer or cleaning compound) C4 - Addition of excessive quantities of ingredients that are toxic under these situations (e.g., niacin poisoning in bread) C5 - Toxic container or pipelines (e.g., galvanized containers with acid food, copper pipe with carbonated beverages) C6 - Raw product/ingredient contaminated by pathogens from animal or environment (e.g., Salmonella enteriditis in egg, Norwalk in shellfish, E. coli in sprouts) C7 - Ingestion of contaminated raw products (e.g., raw shellfish, produce, eggs) C8 - Obtaining foods from polluted sources (e.g., shellfish) C9 - Cross-contamination from raw ingredient of animal origin (e.g., raw poultry on the cutting board) C10 - Bare-handed contact by handler/worker/preparer (e.g., with ready-to-eat food) C11 - Glove-handed contact by handler/worker/preparer (e.g., with ready-to-eat food) C12 - Handling by an infected person or carrier of pathogen (e.g., Staphylococcus, Salmonella, Norwalk agent) C13 - Inadequate cleaning of processing/preparation equipment/utensils – leads to contamination of vehicle (e.g., cutting boards) C14 - Storage in contaminated environment – leads to contamination of vehicle (e.g., store room, refrigerator) C15 - Other source of contamination (please describe in Comments) Proliferation/Amplification Factors:1 P1 - Allowing foods to remain at room or warm outdoor temperature for several hours (e.g., during preparation or holding for service) P2 - Slow cooling (e.g., deep containers or large roasts) P3 - Inadequate cold-holding temperatures (e.g., refrigerator inadequate/not working, iced holding inadequate) P4 - Preparing foods a half day or more before serving (e.g., banquet preparation a day in advance) P5 - Prolonged cold storage for several weeks (e.g., permits slow growth of psychrophilic pathogens) P6 - Insufficient time and/or temperature during hot holding (e.g., malfunctioning equipment, too large a mass of food) P7 - Insufficient acidification (e.g., home canned foods) P8 - Insufficiently low water activity (e.g., smoked/salted fish) P9 - Inadequate thawing of frozen products (e.g., room thawing) P10 - Anaerobic packaging/Modified atmosphere (e.g., vacuum packed fish, salad in gas flushed bag) P11 - Inadequate fermentation (e.g., processed meat, cheese) P12 - Other situations that promote or allow microbial growth or toxic production (please describe in Comments) Survival Factors:1 S1 - Insufficient time and/or temperature during cooking/heat processing (e.g., roasted meats/poultry, canned foods, pasteurization) S2 - Insufficient time and/or temperature during reheating (e.g., sauces, roasts) S3 - Inadequate acidification (e.g., mayonnaise, tomatoes canned) S4 - Insufficient thawing, followed by insufficient cooking (e.g., frozen turkey) S5 - Other process failures that permit the agent to survive (please describe in Comments) Method of Preparation:2 M1 - Foods eaten raw or lightly cooked (e.g., hard shell clams, sunny side up eggs) M2 - Solid masses of potentially hazardous foods (e.g., casseroles, lasagna, stuffing) M3 - Multiple foods (e.g., smorgasbord, buffet) M4 - Cook/serve foods (e.g., steak, fish fillet) M5 - Natural toxicant (e.g., poisonous mushrooms, paralytic shellfish poisoning) M6 - Roasted meat/poultry (e.g., roast beef, roast turkey) M7 - Salads prepared with one or more cooked ingredients (e.g., macaroni, potato, tuna) M8 - Liquid or semi-solid mixtures of potentially hazardous foods (e.g., gravy, chili, sauce) M9 - Chemical contamination (e.g., heavy metal, pesticide) M10 - Baked goods (e.g., pies, eclairs) M11 - Commercially processed foods (e.g., canned fruits and vegetables, ice cream) M12 - Sandwiches (e.g., hot dog, hamburger, Monte Cristo) M13 - Beverages (e.g., carbonated and non-carbonated, milk) M14 - Salads with raw ingredients (e.g., green salad, fruit salad) M15 - Other, does not fit into above categories (please describe in Comments) M16 - Unknown, vehicle was not identified 1 Frank L. Bryan, John J. Guzewich, and Ewen C. D. Todd. Surveillance of Foodborne Disease III. Summary and Presentation of Data on Vehicles and Contributory Factors; Their Value and Limitations. Journal of Food Protection, 60; 6:701-714, 1997. 2 Weingold, S. E., Guzewich JJ, and Fudala JK. Use of foodborne disease data for HACCP risk assessment. Journal of Food Protection, 57; 9:820-830, 1994. Page 2 CDC 52.13 REV. 8/1999 EXAMPLE REPORT Part 2: Additional Information (Please complete as much as possible) 11. Numbers of: Cases with Outcome / Symptom OUTCOME / SYMPTOM Total cases for whom you have information available 12. Incubation Period: 3 6 Shortest: 33.5_ Hospitalization 0 6 Longest: 74.5 Death 0 6 Median: 67.5_ 4 6 6 6 Bloody stools 2 6 Feverish 3 6 Abdominal cramps 6 6 * Headache 4 6 Diarrhea Recovered: (Hours) Healthcare Provider Visit Vomiting 13. Duration of Acute Illness Among Those Who (Hours) Shortest: _2.5_ Longest: _8.0_ Median: (Hours, days) _5.0_ Unknown * Use the following terms, if appropriate, to describe other common characteristics of cases: descend ing paralysi s flushing headach e hemolyti c uremic anaphylaxis arthralgia bradycardia bullous skin lesions bradycardia cough coma diplopia * * myalgia paresthesia septicemia sore throat tachycardia thromobocytopenia temperature reversal urticaria wheezing * 14. If Cohort Investigation Conducted: Event-specific Attack Rate = __________________ / _____________________________________ x 100 = ______ % # of exposed cases # of exposed individ. for whom you have illness info. 15. Implicated Food(s): (Please provide known information. Name of Food e.g., lasagna Main Ingredients pasta, sauce, eggs, beef ALSO ATTACH FOOD SPECIFIC ATTACK RATE TABLE) Reason(s) Suspected Contaminated Ingredient (see below) eggs 4 Raw milk Method of Preparation (see list on page 2) M1 1 3 M1 Food vehicle could not be determined Reason Suspected (choose all that apply): 1 - Statistical evidence from epidemiological investigation 2 - Laboratory evidence (e.g., identification of agent in food) 3 - Compelling supportive information 4 - Other data (e.g., same phage type found on farm that supplied eggs) 5 - Specific evidence lacking but prior experience makes this likely source 16. Where was Food Prepared? (Check all that apply) Restaurant or deli Day care center School Church, temple, etc. Camp Caterer Grocery store Hospital Workplace cafeteria Nursing home 17. Where was Food Eaten? (Check all that apply) Prison, jail Private home Picnic Fair, festival, other temporary/mobile service Contaminated food imported into U.S. Commercial product, served without further preparation ⌧ Other (please describe) __________________ ⌧ Unpublished agency report Epi-Aid Publication (please reference) _____________________________ 19. Remarks: Briefly describe important aspects of the outbreak not covered above (e.g., restaurant closure, product recall, immunoglobulin administration, economic impact, etc.) Minimal cooperation from this group in completion of exposure history and submission of stool specimens Page 3 REV. 8/1999 Nursing home Prison, jail Private home Picnic Fair, festival, or mobile location Other (please describe) __Direct from dairy farm_____________ 18. Other Available Info: CDC 52.13 Restaurant or deli Day care center School ⌧ Church, temple, etc. Camp Grocery Store Hospital Workplace cafeteria EXAMPLE REPORT Part 2: Additional Information (Please complete as much as possible) Not available ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ MI Local Health Departments: Please mail this document to Food and Dairy Division, Michigan Dept. of Agriculture State Health Departments: Please FAX this document to Biostatistics and Information Branch, DBMD, CDC, at (404) 639-2780. Page 4 CDC 52.13 REV. 8/1999 Group Exercise: A Multistate Outbreak of E. coli O157:H7 Infection Group Organization Instructions 1. Select a group leader. The leader guides group discussions and activities, keeps the group on time and is the group's liaison to the facilitator's. 2. Select a group secretary. The secretary records information as needed. In the exercise you are about to do, the secretary will construct an epi curve and timeline during the group's discussion. 3. Select a group listener. The listener can participate and be involved in discussions, but should mainly listen. The listener, under the guidance of the group leader, points out when one of the six problems listed below is occurring. The listener helps make sure that the discussion is balanced, with everyone getting equal opportunity to talk and be heard. REMEMBER: 1. Set preconceived notions aside and be open to the ideas that will be expressed. 2. Be open to changing your mind. 3. React to ideas not people. 4. Respect others, don't interrupt, argue with, antagonize, belittle or discredit the person speaking. 5. It is inappropriate to blame, change the subject, ignore someone's ideas or assume you know other peoples motives. 6. Don't formulate your response while others are speaking. Listen to them and then respond. 7. Your group’s answer to each question should also indicate which module(s) in the Epi-Ready training addressed the topic. Outbreak Recognition: In June 1997, local health agencies identify an increase in lab confirmed E. coli O157:H7 infections. In June 1996, there were 18 infections. However, in June 1997, there were 52 infections. Person: Michigan Residents with Outbreak Strain, June 15 – July 15, 1997 • • • • • 68% Female 96% Bloody Diarrhea 54% Hospitalized 2 Persons HUS 0 Deaths Place: Oakland Midland Kent Washtenaw Livingston Kalamazoo Cheboygan 13 8 6 6 6 4 1 Emmet Ingham Gratiot Gladwin Ottawa Wayne Total Time: 1 1 1 1 1 1 50 Initial Questions: 1. Is this an outbreak? Why or why not? 2. What could account for the increase in cases reported to Michigan Department of Community Health (MDCH)? 3. What additional information would you want to gather initially as part of your investigation? 4. What clues does the epi. curve provide about the nature of the exposure(s)? Update 1- Laboratory Findings MDCH laboratory reports that during the period June 1 – July 31 1997: • 60 infections in 16 counties (compared to 31 infections in same period in 1996) • Of 60 infections, 54 isolates were available for sub typing • 40 of the 54 isolates were identical by PFGE Example: PFGE Analysis - * indicate bands are identical Laboratory Evidence PFGE Analysis ** **** ** ** ** **** ** ** Question 2: a) What do the above laboratory results tell you about the strain(s) of E. coli 0157:H7 identified? b) What would your group use as an initial case definition for this outbreak? Initial Case Definition Developed by Investigation Team: A case was defined as diarrhea (≥ 3 loose stools a day) and/or abdominal cramps in a resident in Michigan with onset of symptoms between June 15 and July 15 and a stool culture yielding E. coli O157:H7 with the outbreak strain PFGE pattern. Question 3: What are the advantages and disadvantages of this case definition? How might you change it? Update 2- Additional Case Information: • • • • • Oakland County - Not many ate meat. Most ate vegetables. Midland County - 4 of 6 at Restaurant X salad bar Kent County - Near vegetarians. Salad eaters. Washtenaw County - 5 of 6 cases female; no links. Ingham County - 1 case: Box lunch of mostly vegetables Compare the age and gender distribution of E. coli O157:H7 cases from the Michigan outbreak and those reported from the U.S. FoodNet sites in 1997. Question 4: Who at the local health department do you think gathered the case information for these laboratory confirmed outbreak-related cases? Question 5: What hypothesis might explain the pattern of disease in this outbreak? Source of agent? Mode of transmission? Epidemiologic Study Design Question 6: What kinds of questions would you ask in the hypothesis-generating interviews? Be sure to consider all possible modes of transmission of E. coli O157:H7. Question 7: How would you choose controls for this study? Question 8: Over what time period would you examine exposures to possible risk factors for cases? For controls? Case Control Study: Local health, Michigan Dept of Ag, Michigan Dept of Community Health and CDC MDA TRACEBACKS MDCH CDC July 16 SUBTYPING CASE CONTROL STUDY OF 30 CASES • • • • 56% of cases ate alfalfa sprouts within 7 days of illness 6% of controls ate alfalfa sprouts Matched Odds ratio = 27 (95% confidence interval 5-558) No other food items significantly associated with illness Hypothesis = Alfalfa Sprouts Question 9: What are possible explanations for the association between illness and sprouts? Question 10: How might you explain the 12 ill persons in the study who did not report eating alfalfa sprouts in the 7 days before they became ill? Question 11: What control measures might you consider at this point? Traceback Investigation Question 12: What information would be needed before undertaking a traceback investigation? I. Key G = Grocery Store R = Restaurant D1 =Distributor 1 D2 =Distributor 2 A = Sprout Grower 1 B = Sprout Grower 2 Traceback Results: Retail Level Traceback Distribution and Production Level Tracebacks SOURCES OF ALFALFA SPROUTS CASES G R G R R G R G R G R R R G R G G R R R G R G R G R R R G R G R G R G R R R G R SPROUT R R DISTRIBUTOR D1 D2 D3 D4 D5 D6 D10 8 Grocery stores 13 Restaurants D7 D8 D9 SPROUT B A GROWER Alfalfa Seed Supplier Traceback Sprout Growers B A * * * Lot 123 Lot 123 Sprout Seed Distributor - KY K Seed supplier - ID S IF IF IF C 48 cases E. coli 0157:H7 96% MICH 1a Lot 123 IF IF CA Storage WF Virginia outbreak discovered to be occurring at the same time. Sprouts implicated as cause. - 48 cases - 46 identical to MI strain - Associated w/ Virginia sprout grower C *No insanitary conditions or E. coli 0157:H7 found from environmental samples IF = Idaho Farms Question 13: Who gathered this information and how do you interpret these results? APPENDIX 1 FOODBORNE ILLNESS GLOSSARY 2 x 2 table - a tabular cross-classification of data such that subcategories of one characteristic are indicated horizontally (in rows) and subcategories of another characteristic are indicated vertically (in columns). Tests of association between characteristics in the columns and rows can be readily applied. Also known as contingency tables. The simplest contingency table is the fourfold or 2 x 2 table. Contingency tables may be extended to include several dimensions of classification. Exposed Not Exposed Ill a c Not Ill b d Asymptomatic - without symptoms. Attack rate - the proportion of a well-defined population that develops illness over a limited period of time, as during an epidemic or outbreak. It is often expressed as a percentage. The difference between attack rates for those exposed and non-exposed to a particular food provides important clues in the investigation of the etiology of an acute outbreak. Carrier - a person or animal that harbors a specific infectious agent, is asymptomatic, and is a potential source of infection for man or animals Case - in epidemiology, a person in the population or study group identified as having the particular disease, health disorder, or condition under investigation. A variety of criteria may be used to identify cases (e.g., individual physicians' diagnoses, registries and notifications, abstracts of clinical records, surveys of the general population, population screening, reporting of defects such as in a dental record). Case-control study – a type of observational analytic study. Enrollment into the study is based on the presence (“case”) or absence (“control”) of disease. Characteristics such as previous exposures are then compared between cases and controls. Case definition – a set of criteria used for investigative purposes to decide whether a person has a particular disease or whether a person is to be included in a “case” category by specifying clinical and laboratory criteria and by specifying limitations on time, place and person. This definition may be used differently in various phases of an investigation. For example, a broad definition might be used early in an investigation to capture all possible cases, while later in the investigation, the definition might be narrowed to capture only definite cases. Often, a “possible” and “confirmed” case definition are generated, with the latter being cases with, for example, a positive laboratory test in addition to symptoms. Chain of custody - a record that establishes the complete chronological disposition of an entity of concern (e.g., laboratory specimen, document). APPENDIX 1 Cluster - aggregation of cases of a disease or other health-related condition, which are closely grouped in space and time. The number of cases may or may not exceed the expected number. Cohort study – type of observational analytic study. Enrollment in the study is based on exposure characteristics or membership in a group. Disease, death, or other healthrelated outcomes are then ascertained and compared. Commercial confidential – trade secrets protected by law from public disclosure (e.g., monitoring records, customer lists, traceback information). Unlawful release of this information can result in legal punishment, including imprisonment. Common source outbreak - outbreak that results from a group of persons being exposed to an infectious agent or toxin from a single source. Confidence intervals (CI) - the computed interval with a given probability (e.g., 95%, that the true value of a variable such as a mean, proportion, or rate is contained within the interval). This is a measure of statistical significance; if a confidence interval includes the value 1.0, it means that there is no association between the exposure in question and the outcome. Confirmed cases – a case that has met the case definition and with a laboratoryidentified etiology. Contact – exposure to a source of an infection, or a person so exposed. Confirmed outbreak - clusters (see above) which are confirmed by laboratory or epidemiologic study to be caused by a common agent or among persons who have shared a common exposure. Contact – exposure to a source of an infection, or a person so exposed. Contaminant - an infectious agent or a chemical or physical hazard. Contamination - the presence of an infectious, chemical, or physical agent or substances in or on water, milk, and food that has the potential to cause harm, including illness or injury. Controls – in a case-control study, comparison group of persons without disease/illness. Epidemic - the occurrence of more cases of disease than expected in a given area or among a specific group of people during a particular period of time. APPENDIX 1 Epidemic curve (Epi curve) - a histogram that shows the course of a disease outbreak or epidemic by plotting the number of cases by time of onset. Epidemic curves help characterize an outbreak and give clues about the source of the outbreak (e.g., common or point source, secondary spread, etc.) Epidemiology – the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems. Firm - any individual, partnership, corporation, or association that deals in articles subject to the FD&C Act. Food-specific attack rate - the food-specific attack rate table compares the illness rate among those who ingested specific foods at an event or meal to the illness rate of those who were at the event or meal but did not ingest these food items. Food worker - person directly involved in producing, harvesting, processing, packaging, preparing, or storing the food under investigation. HACCP (Hazard Analysis and Critical Control Point) - a prevention-based food safety system. HACCP is a system that identifies and monitors specific foodborne hazards biological, chemical, or physical properties - that can adversely affect the safety of the food product. This hazard analysis serves as the basis for establishing critical control points (CCPs). CCPs identify those points in the process that must be controlled to assure the safety of the food. Further, critical limits are established that document the appropriate parameters that must be met at each CCP. Monitoring and verification steps are included in the system, again, to assure that potential risks are controlled. The hazard analysis, critical control points, critical limits, and monitoring and verification steps are documented in a HACCP plan. Host - a person or other living organism that can be infected by an infectious agent under natural conditions. Hypothesis - A supposition arrived at from observation or reflection that leads to refutable predictions. Any conjecture cast in a form that will allow it to be tested and refuted. Implicated food - Food thought to be the outbreak vehicle (i.e. food thought to have made people ill, based on laboratory results and/or epidemiological evidence). Incubation period - The time period between exposure to an infectious agent and the onset of signs and symptoms of disease. Index case - the first case among a number of similar cases that are epidemiologically related. APPENDIX 1 Infection - the entry and development of multiplication of an infectious agent in the body of man or animals. Infection is not synonymous with infectious disease: the result may not be apparent or manifest. The presence of living infectious agents on exterior surfaces of the body is called "infestation" (e.g., pediculosis, scabies). The presence of living infectious agents upon articles of apparel or soiled articles is not infection, but represents contamination of such articles. Line List - a table listing case names, age, sex, onset time, residence, symptoms, employment, etc., which facilitates comparisons of many characteristics for possible similarities or associations. Matching - the process of making a study and comparison group comparable with respect to extraneous factors. Individual matching relies on identifying individual subjects for comparison, each resembling a study subject on the matched variables (e.g., age, gender). Studies using matching in the interview phase use matching in the statistical analysis. Measure of association - a quantified relationship between exposure and disease. Commonly used measures of association are differences between means, proportions or rates, rate ratio, odds ratio, relative risk, and correlation and regression coefficients. Odds Ratio (OR) – a measure of association which quantifies the relationship between an exposure and health outcome from a comparative study. The term odds is defined differently according to the situation under discussion. Using a standard 2 x 2 table, the odds ratio (cross-product ratio) is ad/bc. Exposed Not exposed Ill a c Not Ill B D Onset – the time the first clinical signs or symptoms begin to occur. Outbreak – same as epidemic. Limited to localized increases in the incidence of a disease (e.g., in a village, town, or closed institution). Pathogen - organism capable of causing disease (literally, causing a pathological process). APPENDIX 1 Pesticide - any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest. Pests can be insects, mice and other animals, unwanted plants (weeds), fungi, or microorganisms like bacteria and viruses. Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides and various other substances used to control pests. Under United States law, a pesticide is also any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant. Common pesticides include: algaecides, antifouling agents, anti-microbials, attractants, biocides, disinfectants and sanitizers, fungicides, fumigants, herbicides, insecticides, miticides, microbial pesticides, molluscicides, nematicides, ovicides, pheromones, repellents, rodenticides, defoliants, desiccants, insect growth regulators and plant growth regulators (http://www.epa.gov/opp00001/whatis.htm). Point source outbreak – see common source outbreak. Proliferation/amplification factors – factors that allow proliferation of the etiologic agents: 1. Allowing foods to remain at room or warm-outdoor temperature for several hours 2. Slow cooling 3. Inadequate cold-holding temperature 4. Preparing foods a half-day or more before serving 5. Prolonged cold storage for several weeks 6. Prolonged time and/or insufficient temperature during hot holding 7. Insufficient acidification 8. Insufficiently low water activity 9. Inadequate thawing of frozen products 10. Anaerobic packaging or modified atmosphere 11. Inadequate fermentation Probable Cause – a case without laboratory confirmation that has typical clinical features of the particular disease under investigation without laboratory confirmation. p-value – a measure of the chance the observed results would occur if the null hypothesis were true. The probability associated with a statistical hypothesis will help decide if there is a significant association between exposure and illness or if the results are due to chance (coincidence). Questionnaire – a predetermined set of questions used to collect data (e.g., demographics, clinical data, social status, occupational group). Rate – an expression of the frequency with which an event occurs in a defined population. APPENDIX 1 Recall – A firm’s voluntary removal or correction of a marketed product(s), including its labeling and/or promotional materials, that FDA or FSIS considers to be in violation of the laws it administers, and which the agency would initiate legal action (e.g., seizure or the full range of administrative and civil actions available to the agency). “Recall” does not include a market withdrawal or stock recovery. Regulatory authority – Agency that regulates (permits/licenses and inspects) the substance or establishment under consideration. Relative Risk (RR) – 1. The ratio of the risk of disease or death among the exposed to the risk among the unexposed; this usage is synonymous with risk ratio. 2. Alternatively, the ratio of the cumulative incidence rate in the exposed to the cumulative incidence rate in the unexposed (i.e., the cumulative incidence ratio). 3. The term relative risk has also been used synonymously with odds ratio. The use of the term relative risk for several different quantities arises from the fact that for “rare” disease (e.g., most cancers) all the quantities approximate one another. For common occurrences (e.g., neonatal mortality in infants under 1500g birth weight), the approximations do not hold. Reservoir – the habitat, in which an infectious agent normally lives, grows and multiplies; reservoirs include human reservoirs, animal reservoirs, and environmental reservoirs. Sample size determination – the mathematical process of deciding, before a study begins, how many subjects should be studied. The factors to be taken into account include the incidence or prevalence of the condition being studied, the estimated or putative relationship among the variable in the study, the power that is desired, and the allowable magnitude of type I error. Serotype (or serovar) – a subdivision of a species or subspecies distinguishable from other strains therein on the basis of antigenic character. Source (point of contamination) – the person, animal, object, or substance from which an infectious agent passes to a host. Source of infection should be clearly distinguished from source of contamination, such as overflow of a septic tank contaminating a water supply or an infected cook contaminating a salad. Sporadic case – occurring irregularly and infrequently (e.g., cases of certain infectious diseases) also, a case NOT associated with a known outbreak. Statistically significant association – statistical methods allow an estimate to be made of the probability of the observed or greater degree of association between independent and dependent variables under the null hypothesis. From this estimate, in a sample of given size, the statistical “significance” of a result can be state. Usually the level of statistical significance is stated by the p-value. APPENDIX 1 Strength of association – the magnitude of the measure of association (see above); for example, the size or value of the odds ratio is a measure of the strength of association between an exposure and an illness or other outcome. The larger the odds ratio, the stronger the association. Study design – the procedures and methods, predetermined by an investigator, to be adhered to in conducting a research project. Subtype – see serotype Surveillance – the detection of health problems through the appropriate collection of data, followed by its collation, analysis, interpretation, and dissemination. Active surveillance – agencies regularly contact reporting sources to elicit reports of illnesses. An active surveillance system is likely to provide more complete illness reporting but is more labor intensive and costly to operate. Passive surveillance – agencies receive disease reports from physicians, laboratories, the public, and institutions as mandated by state law. Susceptible – a person lacking sufficient resistance to a particular disease agent to prevent disease if or when exposed. Survival factors - factors that allow survival or fail to inactivate the contaminant: 1. Insufficient time and/or temperature during cooking or heat processing 2. Insufficient time and/or temperature during reheating 3. Inadequate acidification 4. Insufficient thawing followed by insufficient cooking Suspect Cases- persons meeting part of the case definition (see above); for example, persons with specific symptoms (and, perhaps, exposure to a food item of interest) who do not have a laboratory test confirming the cause of their illness; can also refer to persons with laboratory-confirmed illness who are not known to have the exposure of interest. Suspect Outbreak – a cluster of cases linked by time or space which has not been confirmed to be caused by the same agent or item (exposure) but which have characteristics (e.g., an unusual organism or exposure) which makes it likely that the cases are linked not by chance alone. Suspect food - food from the implicated meal that is a likely vehicle for the causative agent. These foods are often identified by the Food Specific Attack RateTable. Symptomatic - demonstrating clinical signs or symptoms (e.g., diarrhea, abdominal pain, fever). APPENDIX 1 Time/temperature abuse - Insufficient time and/or temperature during cooking or heat processing, insufficient time and/or temperature during reheating. Traceback – the method used to determine the source and scope of the product/processes associated with the outbreak and document the distribution and production chain of the product that has been implicated in a foodborne illness or outbreak. Traceforward - once the source of an implicated food item is established, investigators may do a "traceforward" to document the distribution of all implicated lots of food from the source. This can help epidemiologists with case finding and can be used to test hypotheses about the outbreak. Traceforwards should only be used when there is a reasonable degree of confidence that the traceback correctly identified the source of the implicated product. Vector – an animate intermediary in the indirect transmission of an agent that carries the agent from a reservoir to a susceptible host. Vehicle (of infection transmission) - an inanimate intermediary in the indirect transmission of an agent that carries the agent from a reservoir to a susceptible host. Sources for Glossary A Dictionary of Epidemiology, 3rd edition, John M. Last, ed. New York: Oxford University Press, 1995 Principles and Practice of Public Health Surveillance, Steven M. Teutsch and R. Elliott Churchill, eds. NY: Oxford University Press. Stedman's Medical Dictionary, 26th edition, Baltimore: Williams and Wilkins, 1995. Procedures to Investigate Foodborne Illness, 5th edition, IAMFES. Food Code, U.S. Public Health Service, Food and Drug Administration, 1999. FDA Satellite Training: Foodborne Illness Investigations, March 16-18, 1999. FDA Satellite Training: Traceback of Fresh Produce and Other Commodities, June 1617, 1999. EPA website: http://www.epa.gov/opp00001/whatis.htm APPENDIX 2 COMMUNICATIONS This information is intended to supplement information contained in other emergency management plans and documents. Goal: an involved, reasonable, and solution-oriented public Share what is known and what is not known. Provide factual objective information. Avoid complex scientific jargon. Use concrete examples that help put risks into proper context. Effective communication promotes public confidence in the agency handling the issue. Time information sharing to maximize impact; • Make sure informed staff are available to answer questions • Meet media deadlines (e.g., no later than 4:00 p.m. for evening news) The following are specific communication issues related to foodborne illness outbreak investigations that should be considered: I. Preparation Develop standard operating procedures for when and how to inform the media and public about food safety situations and emergencies. Coordinate with communications staff to prepare clear, concise, and complete message(s). Designate one spokesperson per agency to ensure consistent information is delivered. Identify venues for coordinating communications when multiple agencies are involved. II. Outbreak Response Collect accurate information on investigation and response activities. Always follow individual agency’s communications policy to provide information to: • News media • Public • Government officials Educate the spokesperson about the key outbreak-related facts, disease process, and investigation methods being used so that questions are effectively answered and everyone has the same correct information. Share information with your staff so they do not need to get their information from the media. APPENDIX 2 • • • • • • • • • • Make sure messages answer: Who What When Where How Why Provide clear and specific prevention and control. Provide only objective, factual information that emphasizes public health protection. Do not release preliminary information that has not been confirmed. Notify health care providers, and emergency room staff about the situation to enhance surveillance efforts. Coordinate releases of information with involved local, state, and federal agencies so agencies are “on the same page” and up-to-date on situation details. Inform local officials prior to going public. Attempt to provide media and public with “one stop shopping” source of information, and always try to: Return phone calls even when you have nothing new to tell. Anticipate media information needs and respond to media requests even if you have nothing new to report. Provide regular updates in readily accessible format (e.g., briefings in a central location). Consider setting up emergency hotline, extra phone lines, fax and web pages to help meet communication needs. Provide updates frequently while the situation is rapidly evolving then reduce as it stabilizes. III. Termination As situation improves or changes, terminate emergency measures no longer needed. Monitor and evaluate the situation after the investigation is completed to ensure the outbreak has been effectively controlled and that no new cases are occurring. Write final investigation report to share with involved agencies and interested parties. APPENDIX 3 INTERVIEWING SKILLS Acknowledgement: The majority of this information was abstracted from the training program “Foodborne Illness Investigations” March 1999 developed by the FDA’s State Training Branch. I. Task List A. Prior to Interviews Identify specific interviewing objectives. Identify the persons to be interviewed. Select the questionnaire content and format (open-ended vs. closed-ended). Assign and prepare staff who will be interviewing. B. During Interviews Establish rapport with the individuals being interviewed. Ask questions as written if closed-ended questionnaire is being used. Review form before ending interview to ensure fully complete. Ask if individuals have unanswered questions or additional information to share. Thank them for their cooperation. C. After the interview Turn in questionnaires to be reviewed (quality control). Enter information into database as soon as possible. Keep track of who has been interviewed and who is interviewing. APPENDIX 3 II. Task List Related Information A. Prior to Interviews Identify specific interviewing objectives • What information must be collected? − The source of the illness − Means of transmission. • How to gather it? − Target questions to the greatest degree possible so that relevant information is gathered the first time. − Minimize the number of repeat contacts. Identify the persons to be interviewed. • Attempt to understand the individuals involved. − Remember that the goal is to get the facts as they occurred without biasing the results. − Consider what language and format are appropriate to avoid creating intimidating atmosphere; Demographic factors include age, gender, background, and occupation. Involvement in the incident that could create roadblocks. Ö Potential for defensiveness Ö Angry about becoming ill (food preparation) Ö Confused about their involvement − Investigators typically need to gather information from diverse people; Physicians and health care providers, People at the function (both ills and wells), Owner of the establishment, and Cooks, kitchen crew, and wait staff. − Someone may try to work against you. Document the information provided. Check with other sources to verify accuracy and check consistency. APPENDIX 3 Select the questionnaire content and format (open-ended vs. closed-ended). • Core information that should be gathered during every outbreak investigation includes; − Demographic data (e.g., age, sex, address, phone number). − Food history of typically 72 hours. Recognize that this may need to be altered for certain foodborne pathogens (E. coli 0157:H7, Listeria momcytogenes, Hepatitis A). Foods consumed and specific locations of facilities where foods were consumed or purchased (include address whenever possible). Times of consumption. Potential extent of exposure (who else consumed the food?). Ö Gather contact information. For commercially processed foods: Ö Purchase date(s). Ö Product descriptions. • Medical history related to outbreak to verify the diagnosis. − Signs, symptoms, duration. Duration of symptoms typically longer for bacterial than viral. Need to define diarrhea: >3 loose stools in a 24 hour period is a well accepted standard. − Medical care/diagnostics Who did they see? Were they given a diagnosis? If so, what was the diagnosis? Were stool samples collected? Other specimens? − Availability of food or clinical samples (e.g., did diners take food home?) − Potential for non-foodborne routes of transmission (remember last meal bias). Travel Pets or other animal contact Water (drinking or recreational) Illnesses in household or other close contacts (possible person-to-person transmission) Other − Open-ended questions Can be time consuming. Allow person to respond in multiple words. Encourage person to use own words to tell their story. May be more difficult to analyze statistically than yes-no questions. Typically used for initial interviewing before many specifics are known. APPENDIX 3 − Closed-ended questions Closed-ended questions usually have just one answer option. Typically used to gather specific information that can be used for casedefinitions, hypothesis development and testing. Potentially restrictive and leading. Example: "Did you eat the chicken salad? “ Can be used if a response to an open-ended question does not address what the issue (fill in any voids). Example: "What were the foods that you ate?" Then follow up with: "Did you consume any other foods or drinks?" − Obtain list of foods served by caterer or restaurant. Cannot rely on the individual’s memory alone. Get a list of the items served. − Generic Forms Typically used for small outbreaks or early in an investigation before specifics are known. Different generic forms are used by various disciplines at present Ö Routine unconfirmed illnesses: complete IAMFES Form C 1-2 recommended for use by Environmental Health. Ö Routine laboratory confirmed infections: MDCH Enteric Illness Report required for use by communicable disease staff to report to MDCH. − Use of same forms throughout the entire investigation increases consistency. − Customized outbreak questionnaires Consult an epidemiologist or experienced investigator to ensure questions are unbiased. Avoid leading questions or "double barrel" questions which are difficult to answer with a yes or no response. Example: "Did you clean and sanitize the cutting board?" has two parts; “Did you clean it?” and “Did you sanitize it?” Advantages of using a structured questionnaire: Ö Identifies more specifically the information to be gathered, increasing consistency and completeness. Ö Decreases number of follow up contacts to fill in data gaps. Ö Development of questionnaire by team members builds consensus regarding what information is important. Ö How the questions are asked and the order of questions can affect the answers. APPENDIX 3 − Hints on food history questions Assess the individual’s ability to recall food consumption Ö Persons with excellent memories can provide important clues People may not remember fast food meals (example: drive through) as well as meals consumed at sit-down restaurants. Persons who work as food handlers may not have eaten meals at their place of work, but still may have consumed foods from work. Obtaining a menu or accurate list of the items served is important, as it will aid in assisting persons remember accurately what they consumed. Ö Misclassification bias results when investigators inaccurately assess which foods were consumed, resulting in failure to detect a valid association between illness and consumption of a particular food. Word questions differently for weddings/buffets vs. restaurants. Ö Restaurants - People typically remember what they ordered. Ö Buffets – Food items generally not labeled and questions need to clearly describe each food (importance of obtaining a complete list of all foods served). Have an “other food” category on questionnaires. Allows respondents to indicate consumption of a food not previously known to have been served; Ö Check master food list (menu) to verify that it is complete and accurate. Ö Ask clarifying questions to ensure that they are not using a different name for a food on the list (e.g., crab salad and macaroni salad may be the same). Recognize the potential for “last meal bias” which is difficult to rule out when investigating isolated incidents. Identifying food preferences can be helpful when individual is not certain what they ate (e.g., individuals state they definitely would not have eaten buffet items containing pineapple). Ö Assess probability that foods were consumed (definite, probable, possible, definitely not). Ö Have individual identify what they typically would eat for the meal (e.g., cereal or bagel for breakfast). Ö Identifying food categories that they would likely eat or definitely would not eat can provide important clues to help rule in or rule out consumption of certain foods. It may sometimes be appropriate to ask where people sat at an event or their place in line at a buffet style party. Ö Assess person-to-person transmission at a “sick table”. APPENDIX 3 Assign and prepare staff who will be interviewing • Minimize roadblocks to effective two-way communication; − Noise and distractions, − Lack of trust, − Fear of losing job, − Not in persons interest to communicate the truth, and − Reluctance to incriminate self or a friend. • Review characteristics of effective interviewer (as needed) to create an atmosphere that is: − − − − • Non judgmental Objective Sympathetic (strives to maintain confidentiality) Fair An interview is a directed and purposeful "conversation" requiring good communication skills including; − Listening - Interpreting what is said correctly, and − Observation - Picking up on nonverbal cues. • Assign adequate numbers of interviewers and arrange work schedules to allow interviewing at times most likely to yield the best results: − Make it convenient for the person you're interviewing (interviewing is not 9-5 business). − Remember that the public is not obligated to communicate with you. − Maintain good will so individuals are willing to cooperate. − Balance quality of information gathered vs. quantity of interviews that must be completed. • When conducting face-to-face interviews; − Maintain eye contact. − Being sensitive to "signals" that may indicate stress or uneasiness. Body language, Failure to make eye contact, Signs of stress in the voice, and Pauses and inconsistent information. APPENDIX 3 − Adjust your approach and try to regain a comfort level with the person. Allow for differences in personal interviewing styles. Individuality itself is not a problem. Ö Some people naturally come on strong. Ö Others are more passive. Ö Do not let style effect objectivity. Be aware of preconceived opinions and your own bias. Maintain an unhurried pace during the interview. Too direct and rushed questioning may be interpreted as “the third degree”. Focus on the person being interviewed. Seek to understand: Ö Where other people are coming from, Ö How they might react, and Ö What's at stake for them. • Obtain information about disease causing organisms from a current text (see listed references for examples). • Familiarize all interviewers with the questionnaire that will be used. − Reach agreement on format and content. − Go over with the entire group of interviewers. − Pilot testing is recommended. • “Recall bias” a significant factor to overcome. Tips to increase accuracy of recall: − Jog their memory by asking them to think what else they were doing during the time period. − Be prepared with days and dates from that time period (e.g., community events, holidays, school vacations). − Using a calendar to map out individual's activities may be helpful. • Identify appropriate site(s) for interviews. This can help you get a more accurate picture of what happened. − Think about the person's feelings. − Avoid distractions. − Privacy Prefer not to tell the world about the diarrhea Self-incrimination (avoid interviewing food workers with their supervisors present). APPENDIX 3 B. During Interviews Establish rapport with the individuals being interviewed. • People do not care how much you know until they know how much you care. • Emphasize that their cooperation will help find the cause(s) of the outbreak and prevent others from becoming ill. • Inform them that investigators may need to re-interview them at different points in the investigation to gather additional information. − The focus of questions may change. − Need to confirm or clarify information already provided. • Ask at the beginning “Is this a convenient time for you”? If not, reschedule. • Be punctual, keeping appointments as promised. • Begin interviews by letting people know; − − − − Who you are (name and title), Who you work for, Your purpose, and Why you need their cooperation. Example: "There've been reports of possible foodborne illness and I’m investigating to find out what happened." − How long the interview will take. • Practice effective listening skills. − Consider repeating the question and answer to be sure you both agree on what was said. − Avoid leading people to provide answers they believe you want to hear Example: “You didn’t happen to eat the alfalfa sprouts did you?” • Assess the persons communication style: − − − − Action: Bottom-line “just the facts”. Feeling: In touch with their emotions and relationships. Creative: Needs to see the “big picture” and how everything ties in together. Thinking: Loves the details. APPENDIX 3 • Inform individuals up front that multiple contacts may be necessary and the focus of the questions may change. • Ease into the interview by starting with a few directed questions like: − What is your name? − Your address? − Occupation? • Be open and honest without divulging confidential information. • Refer questions regarding medical care to a nurse or health-care provider. Ask questions as written if closed-ended questionnaire is being used. • Make sure to ask questions in the order listed on the questionnaire. • Questions asked in inconsistent order may collect inaccurate information. Example: Make sure to ask these questions in the following order if interested in determining the duration of illness: − − − − “Were you ill? What were your symptoms? Are you still having symptoms? What symptoms are you still having?” Review form before completing interview to ensure fully complete. Ask if individuals have unanswered questions or additional information to share. • Questionnaires may not contain all the appropriate questions. • Involved persons may have information that investigators have not previously considered. • Share noteworthy or unusual findings with the team leader immediately. If for some reason you can't complete the interview: • Make another appointment. • Provide your name and phone number (leave card). • Allow people to call you from the security of their own home. APPENDIX 3 • Invite the person to contact you if they think of anything else. • Thank them for their time. Thank them for their cooperation. C. After the Interview Turn in questionnaires to be reviewed (quality control). • This allows for early identification of inconsistencies in: − Interviewing methods. − Problems with questionnaire design (example: inaccurate list of foods served). Enter information into database as soon as possible. • This allows for timely: − Refinement of case-definitions and working hypotheses, and − Implementation of control actions. Keep track of who has been interviewed and who is interviewing. • Avoid duplication. A master list is important – especially if different agencies are involved. APPENDIX 4 FOOD PREPARATION REVIEW Complaint Number: Establishment Name Address Date & Time of Suspect Meal Phone Number _________________ : am pm (circle) / mo day Date & Time Food Preparation Started yr / mo day : am pm (circle) yr Person Interviewed: Name Position Held: ________________ Review Conducted: Observing Preparation Interviewing person who made original food Other (specify) ________________________ Suspect Food ________________________ DATE PROCESS OBSERVATION AMOUNT OF FOOD TIME OF DAY TEMP OF FOOD EQUIPMENT USED DEPTH OF CONTAINER OR FOOD THICKNESS HAND CONTACT WITH FOOD WORKER’S NAME WORKE R HEALTH PRIOR TO FOOD PREP Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well Y Ill N Well SANITATIO N UNUSUAL EVENTS OTHER INFORMATI ON APPENDIX 4 APPENDIX 4 Form approved OMB No. 0920-0004 Electronic Foodborne Outbreak Reporting System Investigation of a Foodborne Outbreak This form is used to report foodborne disease outbreak investigations to CDC. It is also used to report Salmonella Enteritidis and E. coli O157:H7 outbreak investigations involving any mode of transmission. A foodborne outbreak is defined as the occurrence of two or more cases of a similar illness resulting from the ingestion of a common food in the United States. This form has 6 parts. Part 1 asks for the minimum or basic information needed and must be completed for the investigation to be counted in the CDC annual summary. Part 2 asks for additional information for any foodborne outbreak, while Parts 3 – 6 ask for information concerning specific vehicles or etiologies. Please complete as much of all parts as possible. CDC Use Only __-___________ State Use Only ______________ Part 1: Basic Information 1. Report Type A. □ Please check if this a final report 3. Dates Please enter as many dates as possible Date first case became ill __ __/__ __/__ __ __ __ Month B. □ Please check if data does not support a FOODBORNE outbreak Day Year Date last case became ill __ __/__ __/__ __ __ __ Month Day Year Date first known exposure __ __/__ __/__ __ ____ Month 2. Number of Cases Day Year Date last known exposure __ __/__ __/__ __ __ __ Month Day Year Lab-confirmed cases______(A) Including _______ secondary cases Estimated total ill__________ (If greater than sum A + B) <1 year _____% 20-49 yrs _____% 1-4 yrs _____% ≥50 yrs _____% 5-19 yrs ____% Unknown _____% Reporting state ________________ If multiple states involved: □ Exposure occurred in multiple states □ Exposure occurred in single state, but cases resided in multiple states Other states: __________________ _____________________________ _____________________________ Reporting county_______________ If multiple counties involved: □ Exposure occurred in multiple counties □ Exposure occurred in one county, but cases resided in multiple counties Other counties: ________________ _____________________________ _____________________________ Probable cases______(B) Including _______ secondary cases 5. Approximate Percentage of Cases in Each Age Group 4. Location of Exposure 6. Sex 7. Investigation Methods (Check all that apply) (Estimated percent of the total cases) □ Interviews of only cases □ Food preparation review □ Investigation at factory or production plant □ Investigation at original source Male___________% Female___________% □ Case-control study □ Cohort study (farm, marine estuary, etc.) □ Food product traceback □ Environment / food sample cultures 8. Implicated Food(s): (Please provide known information) Name of Food e.g., Lasagna Main Ingredient(s) Contaminated Ingredient(s) e.g., Pasta, sauce, eggs, beef e.g., Eggs Reason(s) Suspected (See codes just below) e.g., 4 Method of Preparation (See attached codes) e.g., M1 1) 2) 3) □ Food vehicle undetermined Reason Suspected (List above all that apply) 1 - Statistical evidence from epidemiological investigation 2 - Laboratory evidence (e.g., identification of agent in food) 3 - Compelling supportive information 4 - Other data (e.g., same phage type found on farm that supplied eggs) 5 - Specific evidence lacking but prior experience makes it likely source CDC 52.13 revised November, 2004 Public reporting burden of this collection of information is estimated to average 20 minutes per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. An agency may not conduct or sponsor, and a person is not required to respond to a collection of information unless it displays a currently valid OMB control number. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to CDC/ATSDR Reports Clearance Officer; 1600 Clifton Road NE, MS D-74, Atlanta, Georgia 30333; ATTN: PRA (0920-0004). APPENDIX 4 9. Etiology: (Name the bacteria, virus, parasite, or toxin. If available, include the serotype and other characteristics such as phage type, virulence factors, and metabolic profile. Confirmation criteria available at http://www.cdc.gov/foodborneoutbreaks/guide_fd.htm or MMWR2000/Vol. 49/SS1/App. B) Etiology Serotype 1) Other Characteristics (e.g., phage type) Detected In (See codes just below) □ Confirmed □ Confirmed □ Confirmed 2) 3) □ Etiology undetermined Detected In (List above all that apply) 1 - Patient Specimen(s) 2 - Food Specimen(s) 3 -Environment specimen(s) 4 - Food Worker specimen(s) 10. Isolate Subtype State Lab ID PFGE (PulseNet designation) PFGE (PulseNet designation) 1) 2) 3) 11. Contributing Factors (Check all that apply. See attached codes and explanations) □ Contributing factors unknown Contamination Factor □C1 □C2 □C3 □C4 □C5 □C6 □C7 □C8 □C9 □C10 □C11 □C12 □C13 □C14 □C15 (describe in Comments) □ N/A Proliferation/Amplification Factor (bacterial outbreaks only) □P1 □P2 □P3 □P4 □P5 □P6 □P7 □P8 □P9 □P10 □P11 □P12 (describe in Comments) □ N/A Survival Factor (microbial outbreaks only) □S1 □S2 □S3 □S4 □S5 (describe in Comments) □N/A □ Was food-worker implicated as the source of contamination? □ Yes □ No If yes, please check only one of following □ laboratory and epidemiologic evidence □ epidemiologic evidence (w/o lab confirmation) □ lab evidence (w/o epidemiologic evidence) □ prior experience makes this the likely source (please explain in Comments) CDC 52.13 revised November, 2004 APPENDIX 4 Part 2: Additional Information 12. Symptoms, Signs and Outcomes Cases with Total cases for whom Feature outcome/ feature you have information available Healthcare provider visit Hospitalization Death 13. Incubation Period (Circle appropriate units) Shortest______(Hours, Days) Longest______(Hours, Days) Median ______(Hours, Days) □ Unknown Vomiting 14. Duration of Illness (Among those who recovered) (Circle appropriate units) Shortest______(Hours, Days) Longest______(Hours, Days) Median ______(Hours, Days) □ Unknown Diarrhea Bloody stools ∗ Use the following terms, if appropriate, to describe other common Fever characteristics of cases Abdominal cramps Anaphylaxis Arthralgia Bradycardia Bullous skin lesions Coma Cough Descending paralysis Diplopia Flushing HUS or TTP Asymptomatic * * * Headache Hypotension Itching Jaundice Lethargy Myalgia Paresthesia Septicemia Sore throat Tachycardia Temperature reversal Thrombocytopenia Urticaria Wheezing 15. If Cohort Investigation Conducted: Attack rate* = __________/ __________________________________ x 100 = ________% Exposed and ill Total number exposed for whom you have illness information * The attack rate is applied to persons in a cohort who were exposed to the implicated vehicle. The numerator is the number of persons who were exposed and became ill; the denominator is the total number of persons exposed to the implicated vehicle. If the vehicle is unknown, then the attack rate should not be calculated. 16. Location Where Food Was Prepared 17. Location of Exposure or Where Food Was Eaten (Check all that apply) □Restaurant or deli □ Nursing home □ Day care center □ Prison, jail □ School □ Private home □ Office setting □ Workplace, not cafeteria □ Workplace cafeteria □ Wedding reception □ Banquet Facility □ Church, temple, etc □ Picnic □ Camp □ Caterer □ Contaminated food imported into U.S. □ Grocery Store □ Hospital □ Fair, festival, other temporary/ mobile services □ Commercial product, served without further preparation □ Unknown or undetermined □ Other (Describe) ________________________________ (Check all that apply) □ Restaurant or deli □ Nursing Home □ Day care center □ Prison, jail □ School □ Private home □ Office Setting □ Workplace, not cafeteria □ Workplace cafeteria □ Wedding Reception □ Banquet Facility □ Church, temple, etc. □ Picnic □ Camp □ Grocery Store □ Hospital □ Fair, festival, temporary/ mobile service □ Unknown or undetermined □ Other (Describe) _____________________________________ 18. Trace back □ Please check if trace back conducted Source to which trace back led: Source (e.g., Chicken farm, Tomato processing plant) CDC 52.13 revised November, 2004 Location of Source State Comments Country APPENDIX 4 19. Recall □ Please check if any food product recalled Recall Comments __________________________________________________________ __________________________________________________________ __________________________________________________________ __________________________________________________________ __________________________________________________________ 20. Available Reports (Please attach) □ Unpublished agency report □ Epi-Aid report □ Publication (please reference if not attached) __________________________________________________________ __________________________________________________________ 21. Agency reporting this outbreak ___________________________________________ 22. Remarks Contact person: Name _____________________________________ Title ______________________________________ Phone _____________________________________ Fax _______________________________________ E-mail ____________________________________ ________________________________________________________ Briefly describe important aspects of the outbreak not covered above (e.g., restaurant closure, immunoglobin administration, economic impact, etc) ____________________________________________ ____________________________________________ ____________________________________________ ____________________________________________ Part 3: School Questions 1. Did the outbreak involve a single or multiple schools? □ Single □ Multiple (If yes, number of schools____) 2. School characteristics (for all involved students in all involved schools) a. Total approximate enrollment _____ (number of students) □ Unknown or Undetermined b. Grade level(s) (Please check all grades affected) □ Preschool □ Grade School (grades K-12) Please check all grades affected: □K □1st □ College/University/Technical School □ Unknown or Undetermined □2nd □3rd □4th □5th □6th □7th □8th □9th □10th □11th □12th c. Primary funding of involved school(s) □ Public □ Private □ Unknown or Undetermined 3. Describe the preparation of the implicated item: □ Heat and serve (item mostly prepared or cooked off-site, reheated on-site) □ Served a-la-carte □ Serve only (preheated or served cold) □ Cooked on site using primary ingredients □ Provided by a food service management company □ Provided by a fast food vendor □ Provided by a pre-plate company □ Part of a club/ fundraising event □ Made in the classroom □ Brought by a student/teacher/parent □ Other ___________________ □ Unknown or Undetermined CDC 52.13 revised November, 2004 4. How many times has the state, county or local health department inspected this school cafeteria or kitchen in the 12 months before the outbreak?* □ Once □ Twice □ More than two times □ Not inspected □ Unknown or Undetermined 5. Does the school have a HACCP plan in place for the school feeding program?* □ Yes □ No □ Unknown or Undetermined *If there are multiple schools involved, please answer according to the most affected school APPENDIX 4 6. Was implicated food item provided to the school through the National School Lunch/Breakfast Program? □ Yes □ No □ Unknown or Undetermined If Yes, Was the implicated food item donated/purchased by : □ USDA through the Commodity Distribution Program □ Purchased commercially by the state/school authority □ Other_____________________________ □ Unknown or Undetermined Part 4: Ground Beef 1. What percentage of ill persons (for whom information is available) ate ground beef raw or undercooked? _____% 2. Was ground beef case ready? (Ground beef that comes from a manufacturer packaged for sale and not altered or repackaged by the retailer) □ Yes □ No □ Unknown or Undetermined 3. Was the beef ground or reground by the retailer? □ Yes □ No □ Unknown or Undetermined If yes, was anything added to the beef during grinding (e.g., shop trim or any product to alter the fat content)____________________________________________________________________________ Part 5: Mode of Transmission (Enterohemorrhagic E. coli or Salmonella Enteritidis only) 1. Mode of Transmission (for greater than 50% of cases) Select one: □ Food □ Person to person □ Swimming or recreational water □ Drinking water □ Contact with animals or their environment □ Unknown or Undetermined Part 6: Additional Egg Questions 1. Were Eggs: (Check all that apply) □ in-shell, un-pasteurized? □ in-shell, pasteurized? □ liquid or dry egg product? □ stored with inadequate refrigeration during or after sale? □ consumed raw? □ consumed undercooked? □ pooled? 2. If eggs traced back to farm, was Salmonella Enteritidis found on the farm? □ Yes □ No □ Unknown or Undetermined Comment:_____________________________________________________________________________________________ _____________________________________________________________________________________________ CDC 52.13 revised November, 2004 APPENDIX 4 Contamination Factors:1 C1 - Toxic substance part of tissue (e.g., ciguatera) C2 - Poisonous substance intentionally added (e.g., cyanide or phenolphthalein added to cause illness) C3 - Poisonous or physical substance accidentally/incidentally added (e.g., sanitizer or cleaning compound) C4 - Addition of excessive quantities of ingredients that are toxic under these situations (e.g., niacin poisoning in bread) C5 - Toxic container or pipelines (e.g., galvanized containers with acid food, copper pipe with carbonated beverages) C6 - Raw product/ingredient contaminated by pathogens from animal or environment (e.g., Salmonella Enteriditis in egg, Norwalk in shellfish, E. coli in sprouts) C7 - Ingestion of contaminated raw products (e.g., raw shellfish, produce, eggs) C8 - Obtaining foods from polluted sources (e.g., shellfish) C9 - Cross-contamination from raw ingredient of animal origin (e.g., raw poultry on the cutting board) C10 - Bare-handed contact by handler/worker/preparer (e.g., with ready-to-eat food) C11 - Glove-handed contact by handler/worker/preparer (e.g., with ready-to-eat food) C12 - Handling by an infected person or carrier of pathogen (e.g., Staphylococcus, Salmonella, Norwalk agent) C13 - Inadequate cleaning of processing/preparation equipment/utensils B leads to contamination of vehicle (e.g., cutting boards) C14 - Storage in contaminated environment B leads to contamination of vehicle (e.g., store room, refrigerator) C15 - Other source of contamination (please describe in Comments) Proliferation/Amplification Factors: 1 P1 - Allowing foods to remain at room or warm outdoor temperature for several hours (e.g., during preparation or holding for service) P2 - Slow cooling (e.g., deep containers or large roasts) P3 - Inadequate cold-holding temperatures (e.g., refrigerator inadequate/not working, iced holding inadequate) P4 - Preparing foods a half day or more before serving (e.g., banquet preparation a day in advance) P5 - Prolonged cold storage for several weeks (e.g., permits slow growth of psychrophilic pathogens) P6 - Insufficient time and/or temperature during hot holding (e.g., malfunctioning equipment, too large a mass of food) P7 - Insufficient acidification (e.g., home canned foods) P8 - Insufficiently low water activity (e.g., smoked/salted fish) P9 - Inadequate thawing of frozen products (e.g., room thawing) P10 - Anaerobic packaging/Modified atmosphere (e.g., vacuum packed fish, salad in gas flushed bag) P11 - Inadequate fermentation (e.g., processed meat, cheese) P12 - Other situations that promote or allow microbial growth or toxic production (please describe in Comments) Survival Factors:1 S1 - Insufficient time and/or temperature during initial cooking/heat processing (e.g., roasted meats/poultry, canned foods, pasteurization) S2 - Insufficient time and/or temperature during reheating (e.g., sauces, roasts) S3 - Inadequate acidification (e.g., mayonnaise, tomatoes canned) S4 - Insufficient thawing, followed by insufficient cooking (e.g., frozen turkey) S5 - Other process failures that permit the agent to survive (please describe in Comments) Method of Preparation:2 M1 - Foods eaten raw or lightly cooked (e.g., hard shell clams, sunny side up eggs) M2 - Solid masses of potentially hazardous foods (e.g., casseroles, lasagna, stuffing) M3 - Multiple foods (e.g., smorgasbord, buffet) M4 - Cook/serve foods (e.g., steak, fish fillet) M5 - Natural toxicant (e.g., poisonous mushrooms, paralytic shellfish poisoning) M6 - Roasted meat/poultry (e.g., roast beef, roast turkey) M7 - Salads prepared with one or more cooked ingredients (e.g., macaroni, potato, tuna) M8 - Liquid or semi-solid mixtures of potentially hazardous foods (e.g., gravy, chili, sauce) M9 - Chemical contamination (e.g., heavy metal, pesticide) M10 - Baked goods (e.g., pies, éclairs) M11 - Commercially processed foods (e.g., canned fruits and vegetables, ice cream) M12 - Sandwiches (e.g., hot dog, hamburger, Monte Cristo) M13 - Beverages (e.g., carbonated and non-carbonated, milk) M14 - Salads with raw ingredients (e.g., green salad, fruit salad) M15 - Other, does not fit into above categories (please describe in Comments) M16 - Unknown, vehicle was not identified 1 Frank L. Bryan, John J. Guzewich, and Ewen C. D. Todd. Surveillance of Foodborne Disease III. Summary and Presentation of Data on Vehicles and Contributory Factors; Their Value and Limitations. Journal of Food Protection, 60; 6:701-714, 1997. 2 Weingold, S. E., Guzewich JJ, and Fudala JK. Use of foodborne disease data for HACCP risk assessment. Journal of Food Protection, 57; 9:820-830, 1994. CDC 52.13 revised November, 2004 APPENDIX 4 APPENDIX 4 APPENDIX 4 APPENDIX 4 APPENDIX 5 WEB-BASED RESOURCES TO EXPLORE Epidemiologic Case Studies, www.phppo.cdc.gov/phtn/casestudies These case studies are interactive exercises developed to teach epidemiologic principles and practices. They are based on real-life outbreaks and public health problems and were developed in collaboration with the original investigators and experts from the Centers for Disease Control and Prevention. The case studies require students to apply their epidemiologic knowledge and skills to problems confronted by public health practitioners at the local, state, and national level every day. Two types of epidemiologic case studies are available. The computer-based case studies can be used as a self-study and in the classroom setting. The classroom case studies are primarily for use in a group setting with a knowledgeable instructor. Instructor Guides are available on-line. Principles of Epidemiology, www.phppo.cdc.gov/PHTN/catalog/305g.asp This is a print-based self study course available to download as PDF’s or as a textbook you can order from the Public Health Foundation. This text serves as an excellent reference tool for the application of epidemiology and biostatistics. Bioterrorist Attack on Food: A Tabletop Exercise, http://healthlinks.washington.edu/nwcphp/edu/phe/ This learning exercise is an opportunity for public health personnel and their local emergency counterparts to gain skills and knowledge in preparing for and responding to a large-scale communicable disease outbreak or bioterrorism event. Epi Info™ – Centers for Disease Control and Prevention, www.cdc.gov/epiinfo/ With Epi Info™ and a personal computer, epidemiologists and other public health and medical professionals can rapidly develop a questionnaire or form, customize the data entry process, and enter and analyze data. Epidemiologic statistics, tables, graphs, and maps are produced with simple commands such as READ, FREQ, LIST, TABLES, GRAPH, and MAP. Epi Map displays geographic maps with data from Epi Info™. NEHA Training, www.nehatraining.com is the Regulator’s Choice™ for food safety education and training. Their materials and publications provide some of the best defenses for taking a proactive approach to preventing outbreaks before they occur. Their books contain all essential microbiological and technical food safety principles in ways that are easy to read, understand, and retain. In addition, NEHA Training registers qualified food safety trainers and provides them with the support and resources they need to deliver effective training. For more information about their books or training resources visit www.nehatraining.com or call 303-756-9090 x340. Investigating an Outbreak: Pharyngitis in Louisiana, www.phppo.cdc.gov/PHTN/catalog/303g.asp Fun interactive simulation where you conduct the outbreak investigation to determine the source and control measures to undertake. This product is DOS-based…an antique that is compatible with Windows! “E. coli O157:H7 Infection in Michigan” and “Botulism in Argentina” Computer-based Case Studies, http://www.phppo.cdc.gov/phtn/casestudies/ The Centers for Disease Control and Prevention recommend this computer-based case study, “E. coli O157:H7 Infection in Michigan”. Based on a real-life outbreak investigation by Dr. Thomas Breuer and colleagues in 1997, this self-instructional, interactive exercise teaches epidemiologic skills in outbreak investigation and allows students to apply and practice those skills. APPENDIX 5 UNC’s John Snow Case Study, www.sph.unc.edu/courses/john_snow/ This is a short engaging case study that walks you through the classic John Snow investigation. It sets the foundation for epidemiology and public health. Outbreak Investigation Toolkit, www.cdc.gov/foodborneoutbreaks This site has been established to provide public health officials, researchers, and the general public with information on foodborne disease outbreaks. The toolkit includes: • • Standard Questionnaire Specimen Collection Guide • • Confirmation Criteria for Foodborne Outbreak Etiologies Atlas of Food Consumption • • PHLIS (Public Health Laboratory Information System) and more! CDC Resources for Local Health Departments, http://www.phppo.cdc.gov/dphsdr/localhealth/index.asp This site is intended as a resource for Local Health Department personnel to gain easy access to CDC's public health practice materials and information. Johns Hopkins Bloomberg School of Public Health, http://ocw.jhsph.edu The Johns Hopkins Bloomberg School of Public Health's OPENCOURSEWARE (OCW) project provides access to content of the School's most popular courses. As challenges to the world's health escalate daily, the School feels a moral imperative to provide equal and open access to information and knowledge about the obstacles to the public's health and their potential solutions. CDC Form 52.13/EFORS/Spoon and Fork, http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5510a2.htm?s_cid=ss5510a2_e APPENDIX 6 ANSWERS Graduation Party Blues Food Preparation Review 1. Using the information provided, complete a food preparation flow diagram for one of the following foods: meatballs, spaghetti sauce, rigatoni, chef salad, fried chicken, potato salad, pea salad and fruit salad. Peel potatoes Boil potatoes Drain water to allow cooling To reach-in for cooling Boil eggs Drain water, to refrigerator to cool Peel, chop Refrigerate in shallow pan Chop celery, onions, and green peppers potato salad Mix cold ingredients Cold store in hotel pans Transport Serve 1 APPENDIX 6 2. Complete the food preparation review for the fruit salad with the attached form. FOOD PREPARATION REVIEW Complaint Number: 111 Establishment Name _____Sanborne Home____________ Address Phone Number __555-1212 Date & Time of Suspect Meal 0 6 2 9 0 0 / 1 3 : 0 Mo. day yr. Date & Time Food Preparation Started 0 6 2 8 0 0 / 1 mo day yr. Person Interviewed Name Tilly Olson Review Conducted: _____Sanitarian name 0 am PM (circle) 6 : 0 0 am PM (circle) Position Held: Food Preparer Other (specify) __________________________________ Suspect Food Fruit Salad DATE PROCESS OBSERVATION AMOUNT OF FOOD TIME OF DAY TEMP OF FOOD EQUIPMENT USED DEPTH OF CONTAINER OR FOOD THICKNESS 6/28 Cut up fruits and place them in watermelon halves Unknown 4 PM None taken Knife, cutting board Watermelon halves HAND CONTACT WITH FOOD Y N 2 WORKER’S NAME Tilly WORKER HEALTH PRIOR TO FOOD PREP Ill Well SANITATION UNUSUAL EVENTS OTHER INFORMATION Tilly was ill with GI symptoms. She did not properly wash her hands after using the toilet. She used bare hands to cut up fruit and remove seeds. APPENDIX 6 Answer Sheet Module 4 Group Exercise: Joe’s Thanksgiving Dinner Questions: 1. What type of a study would you perform in order to determine which food caused the illness? Why? Cohort- there is a well-defined population and all of the participants can be identified. 2. What is the attack rate of people who ate turkey that developed vomiting? Diarrhea? Fever? Vomiting: 7/10 or .7 A total of 10 people ate turkey and of those people, 7 became ill with vomiting. Diarrhea: 8/10 or .8 A total of 10 people ate turkey and of those people, 8 became ill with diarrhea. Fever: 5/10 or .5 A total of 10 people ate turkey and of those people, 5 became ill with fever. 3. Fill in the 2x2 table for people who ate pie and became ill. Disease Exposure Yes Yes No 4 4 5 2 to Pie No APPENDIX 6 4. Fill in the 2x2 table for people who ate turkey and became ill. Disease Exposure to turkey Yes No Yes No 8 2 1 4 5. Calculate the relative risk for developing disease if a person ate pie. What does this value mean? RR= a/(a+b) c/(c+d) 4/(4+4) = .5 = .7 5/(5+2) .714 The risk for developing disease given exposure to pie is less than the risk for developing disease without exposure to pie (RR=.714). Therefore, people who ate pie were actually protected from disease. 6. Calculate the relative risk for developing disease if a person ate turkey. What does this value mean? RR= a/(a+b) c/(c+d) 8/(8+2) = 1/(1+4) .8 = 4 .2 The risk for developing disease given exposure to turkey is more than the risk for developing disease without exposure to turkey (RR=4). Therefore, people who ate turkey were four times more likely to develop disease than those who did not. 7. Which food item was more likely to cause illness- the turkey or the pie? Why? Turkey- People who ate turkey were 4 times more at risk for developing the disease. The people who ate pie were protected from disease because their risk of developing illness is less than one. 8. The p-value for the relative risk estimate for turkey consumption is p= .03. What does this mean? What if the p-value was p= .65? A p-value of .03 indicates that we can have a high level of confidence that our four fold estimate of increased risk associated with turkey consumption is very unlikely to be due to chance alone. We are 97% certain that our estimate of 4.0 is not really 1.0 (our 97% confidence interval does not include 1.0). If the p-value = .65 there would be a 35% chance that the RR could actually be 1.0. Therefore, given such a high p-value, we cannot say that our results are statistically significant due to chance alone.