Medical Briefings Measles
Transcription
Medical Briefings Measles
Medical Briefings Mmer Measles Measles is one of the most communicable infectious diseases, with the potential for serious lifethreatening complications. In 1980, before widespread vaccination, the measles virus caused an estimated 2.6 million deaths worldwide. The disease remains one of the leading causes of death among young children globally, despite the availability of a safe and effective vaccine. Also in the most vulnerable groups are: adults over 20 years of age; pregnant women; and people with compromised immune systems, such as those with leukaemia and HIV/AIDS. The overwhelming majority (more than 95%) of measles deaths occur in countries with low per capita incomes and weak health infrastructures – particularly in parts of Africa and Asia. How is Measles Spread? Measles is one of the most contagious viruses ever discovered. It is spread by coughing and sneezing, by close personal contact or by direct personal contact with infected nasal secretions. Up to 90% of susceptible persons in close contact with measles patient will develop measles. The most remarkable thing about the virus is that it's incredibly indestructible. If you were unvaccinated, you could catch the virus from droplets left in the air by an infected person who had coughed in the room hours earlier. No other virus can do that. It also lives on surfaces for hours, finding new hosts in the unimmunized. It can be transmitted from 4 days prior to the onset of the rash, to 4 days after the rash erupts. The virus infects the mucous membranes and then spreads throughout the body. Measles is a human disease and is not known to occur in animals. Signs and Symptoms of Measles After an incubation period of 10 to 12 days, measles appears as a fever, cough, stuffy/runny nose, and bloodshot and watery eyes. Loss of appetite and low energy are common too. Several days after these initial symptoms, an uncomfortable spotty rash begins to spread all over the body, starting on the face and neck, and moving downward - it also causes white spots on the inside of the cheeks. The rash usually lasts for 3 to 5 days and then fades away. In uncomplicated cases, people who get measles start to recover as soon as the rash appears and feel back to normal in about 2 to 3 weeks. Signs and Symptoms Fever (up to 105°F/41°C) Cough Runny or stuffy nose Conjunctivitis (bloodshot, watery eyes) Rash on face and body White spots inside cheeks Complications of Infection In most cases, measles is not deadly, but it's almost always debilitating, bringing on a weeks-long fever, rash, and painful, watery eyes. Up to 40% of people experience complications, and 1 or 2 children in 1,000 die. Common complications: Middle ear infections leading to deafness Pneumonia Diarrhoea Serious complications, especially in children: Blindness Encephalitis (swelling of the brain) often leading to permanent brain damage (~ 1 in 1,000) Death from respiratory and neurological complications (~ 1 or 2 in 1,000) Rarely, behavioural and mental deterioration and seizures 7-10 yrs after infection. How is Measles Treated? No specific antiviral treatment exists for measles virus. Severe complications from measles can be avoided through supportive care that ensures good nutrition, adequate fluid intake and treatment of dehydration with oral rehydration solutions. This solution replaces fluids and other essential elements that are lost through diarrhoea or vomiting. Antibiotics may be prescribed in the event of eye and ear infections, and pneumonia. Infected people should be isolated for 4 days after they develop a rash. People who are at risk of severe illness and complications from measles, such as infants younger than 12 months of age, pregnant women without evidence of measles immunity, and people with severely compromised immune systems, should receive immunoglobulin injections, where this is available. All children in developing countries diagnosed with measles should receive two doses of vitamin A supplements, given 24 hours apart. This treatment restores low vitamin A levels during measles that occur even in well-nourished children and can help prevent eye damage and blindness. Vitamin A supplements have been shown to reduce the number of deaths from measles by 50%. People who recover from measles are immune for the rest of their lives. Prevention Routine measles vaccination for children, combined with mass immunization campaigns in countries with high case and death rates, are key public health strategies to reduce global measles deaths. The measles vaccine has been in use for 50 years. It is safe, effective and inexpensive. It costs approximately $1 US to immunize a child against measles. Two doses of the vaccine are recommended to ensure full immunity and prevent outbreaks, as about 15% of vaccinated children fail to develop immunity from the first dose. The measles vaccine is often incorporated with rubella and/or mumps vaccines [MMR vaccine] in countries where these illnesses are problems. Adding rubella to measles vaccine increases the cost only slightly, and allows for shared delivery and administration costs. The measles vaccine is not licensed for use on babies younger than 12 months. That means that, for the first year of life, babies depend on the fact that everybody else around them gets vaccinated. This essentially creates a firewall: if other people are vaccinated, they won't catch the disease - and won't spread it to young children who cannot get protection. This is what scientists call "herd immunity," and it’s a huge reason why we get vaccines in the first place. The shots aren't just about protecting ourselves from measles, mumps, the flu, or other diseases. They're about making it really hard for those who are medically frail (like the elderly) and those who can't get the vaccine (often babies and pregnant women) to catch a disease that could be devastating to them. The vaccinated people form something like a fence around the vulnerable people, making it more difficult for the disease to penetrate. Can Measles be Eliminated? Over the last 30 years, the incidence of the disease has dropped dramatically. In 1980, around 2.6 million died globally from measles and by 2013 that number was just 145,700. But measles continues to circulate around the world, even in places you don’t always think of as hot beds of deadly infectious diseases. Measles outbreaks have been so bad in Europe that the World Health Organization has put out a strong cry to policymakers, health workers and parents, asking them to immediately “step up vaccination against measles.” In the last 12 months there have been more than 22,000 cases of measles reported in Europe. This included more than 3,000 cases in Russia, 1,674 in Italy, and nearly 600 cases in Germany, threatening Europe’s goal of eliminating the disease by the end of 2015. Measles Anywhere Means Measles Everywhere In the US in the year 2000, measles was declared eliminated on the grounds that there was no endemic measles transmission recorded for 12 months. However, measles is common in many parts of the world and outbreaks have still occurred every year since, through returning travellers. Last year, more than half of around 600 measles cases in the US were caused by a single unvaccinated Ohio man returning from the Philippines - where the disease was circulating - and spreading measles to his similarly unimmunized community. The US is currently experiencing a large, multi-state outbreak of measles that originated in Disneyland in California. The outbreak started in December 2014 and has spread to more than a dozen other states. And that’s exactly typical of how outbreaks start. Debate is going on around the world, especially in affected communities, about the recommendations for measles vaccination in populations. The dilemma hinges on whether or not the vaccination program should be made compulsory. There have been claims in the past – later discredited – that the vaccines could be linked to autism. Medical professionals and governments around the world say vaccination is safe and recommend it as a preventative measure. The WHO Fourth Millennium Development Goal (MDG 4) aims to reduce the under-5 year olds mortality rate by two-thirds between 1990 and 2015. Given that measles vaccination coverage can be considered a marker of access to child health services, routine measles vaccination coverage has been selected as an indicator of progress towards achieving MDG 4. Overwhelming evidence demonstrates the benefit of providing universal access to measles-containing vaccines. The measles virus could theoretically be eradicated, never to infect another human again. That’s because it fits the profile of diseases that can be eradicated: people, and not animals, are the only carriers of the virus (so eradication wouldn't require killing off an entire animal species); there is an effective vaccine; and there is a readily available and accurate diagnostic test to identify the disease. Globally, there’s some good news on this front: during 2013, about 205 million children (84% of the world's children) were vaccinated against measles during mass vaccination campaigns in 34 countries - an increase from 73% in 2000. All WHO Regions have now established goals to eliminate this preventable killer disease by 2020. But this isn’t enough for total eradication. While most (about 95%) of today’s outbreaks occur in developing countries, particularly in Africa and Asia, measles can take off anywhere, as has been seen in the Disney outbreak, as long as there are enough people who did not get the vaccine. Key Points Measles is one of the leading causes of death among young children even though a safe and cost-effective vaccine is available. In 2013, there were 145,000 death from measles globally. Measles vaccination resulted in a 75% drop in deaths from measles between 2000 and 2013 worldwide. In 2013, about 84% of the world's children received one dose of measles vaccine by their first birthday through routine health services – up from 73% in 2000. During 2000-2013, measles vaccination prevented over 15 million deaths making measles vaccine one of the most cost effective successes in public health. Ebola-Hit Countries at Risk of Massive Measles Outbreak As the death rate from the largest ever outbreak of Ebola Virus passes 10,000, a study in the journal Science suggests there could be even more deaths from other diseases because of the devastating impact on the countries' vaccination programmes. Many healthcare facilities have closed and the fear of Ebola meant people did not show up at those that remained. It has had a knock-on effect on immunisation campaigns for measles, polio, TB and other diseases. An international team of scientists ran detailed models assuming 75% of vaccination programmes had been disrupted. They estimated that 20,000 more people were becoming susceptible to measles every month. At the start of the outbreak they said there were 778,000 unvaccinated children and the total would increase to 1,129,000 after 18 months of the outbreak. Their sophisticated predictions suggested this would translate to an additional 100,000 measles cases, on top of the 127,000 that would be anticipated in a pre-Ebola measles outbreak. It could lead to 16,000 extra deaths, more than have died from Ebola, the team suggested. Sources WHO: Measles Mortality Reduction- a successful initiative http://www.who.int/immunization/newsroom/measles/en/ Nathnac Travel Update March 2014 https://www.nathnac.org/pro/clinical_updates/measles_travel_010414.htm European Centre for Disease Control: Surveillance 2013 http://www.ecdc.europa.eu/en/publications/Publications/measles-rubella-surveillance-oct-2013.pdf Reduced vaccination and the risk of measles and other childhood infections post-Ebola. Science, 2015 http://www.sciencedaily.com/releases/2015/03/150312143030.htm ____________________________________________________________________________________________________________ Written by Dr Adrian Hyzler MBChB MBA Senior Medical Officer, Healix International © Healix International 2015. All rights reserved. th Published 28 April, 2015 E: [email protected] www.healix-international.com UK Healix International Healix House Esher Green Esher KT10 8AB United Kingdom T+44 (0)20 8481 7720 USA HX Global 1 International Plaza Suite 550 Philadelphia PA 19113 USA. T+1 215 282 5150 Australia Healix International Suite 10a, 30 Florence Street Newstead, Brisbane Queensland Australia, 4006 T+61 (0)7 3164 9500 New Zealand Healix International Suite 8 40 Arrenway Drive Rosedale Auckland New Zealand 0632. 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