Lyme Disease – Deer Ticks in the Northeast

Risk of Deer Ticks and TBD in the
New England Landscape
~Fifteen Species of Ticks in
northern New England (NNE)
Four of major veterinary or public health concern
Ixodes scapularis – the deer tick – LD, AP, BA
Ix. cookei – the woodchuck tick – POW virus
Dermacentor variabilis – the dog tick – RMSF
Amblyomma americanum – the Lone Star tick*
* Not established in NNE - YET!
Ticks and Lyme Disease
•The deer tick (or black-legged) tick = the only
vector of Lyme disease
•Ticks are not insects, but are arthopods, more
closely related to spiders, lobsters, and dust mites
•Four life stages, with a usual life cycle lasting two
years
LD Distribution (US)
LD – an emerging infectious disease!!
Centers for Disease Control and Prevention, 2012.
Tick Distribution
(ME)
Ixodes scapularis
distribution
monitored by a tick
submission program
through MMCRI and
the Maine Forest
Service. 1989-2013.
Ticks and Lyme Disease
Bite is Worse Than the Bark
• Hypostome of the
deer tick is barbed.
• Ticks secrete an
anesthesia and
anticoagulant when
biting.
• To transmit the Lyme
bacterium, ticks must
feed for at least 36
hours!
A
B
A) Scanning
electron
microscope (SEM)
image of a deer
tick. Courtesy of
MicroAngela.
B. Borrelia
burgdorferi
spirochete. CDC.
Prompt Removal of Ticks Important!
Piesman and Dolan (2002). J Med Ent
Lyme Disease in Maine
2009
2008
2007
2006
2005
2004
Lyme Disease is becoming more widespread in Maine
Seasonality of Cases (US)
US Centers for Disease Control
Dog Tick Seasonality NNE
Nymph
40
20
0
Deer Tick Seasonality NNE
Nymph
120
80
40
0
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
51
1
3
5
7
9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
960
880
Adults
800
720
640
560
480
400
320
240
160
80
0
Jan
Feb
Mar
April
May
YEAR (months)
July
June
Aug
Sept
Oct
Nov
Dec
Deer Ticks Vs. Dog Ticks
• Dog ticks have either a white scutum or
white ‘racing stripes.’
• Generally, deer ticks prefer woods while
dog ticks prefer open habitats.
• Adult dog ticks are large in the summer
while deer tick nymphs are small.
• If you find ticks in fall or spring, they are
probably deer ticks.
Deer Ticks Vs. Dog Ticks
• Dog ticks have either a white scutum
(female) or white ‘racing stripes’ (male).
Deer Ticks Vs. Dog Ticks
Other Tick-borne Diseases
• Anaplasmosis (HGA) and babesiosis
• Spread by deer ticks
• Very rare in Maine and, generally,not as
common as Lyme disease.
• Symptoms of HGE include fever,
headache, malaise, muscle & joint
aches, nausea, vomiting, diarrhea,
cough,confusion, and occasional rash.
Other Tick-borne Diseases
• Anaplsmosis (HGA) and babesiosis
• Spread by deer ticks
• Very rare in Maine and, generally,not as
common as Lyme disease.
• Symptoms of human babesiosis include
malaria-like illness characterized
by fever, chills, sweats, fatigue,
nausea, and vomiting.
Other Tick-borne Diseases
• Powassan/Deer Tick
Virus
– Two distinct lineages
• Type I – Ixodes cookei
and
mustelids/woodchucks
• Type II – Ixodes
scapularis and
mice/deer
Other Tick-borne Diseases
• Powassan/Deer Tick
Virus
– 4 human cases 19992004, presumptive
Type I
– 1 human case (fatal)
2013, confirmed Type
II
Outbreak of Powassan Encephalitis Maine and Vermont, 1999-2001.
MMWR 50(35);761-4
From 1999-2001, four cases of POW
encephalitis were found in Maine and
Vermont. Persons were tested for other
infections found in the northeast after tests
for West Nile virus (WNV) infection were
negative.
Powassan Virus
• Powassan virus investigation
• Positive skunks and raccoons at several of
the human case sites
• An urban or suburban
wildlife problem???
•Different risk factors
for different lineages?
Powassan and the Human/
Wildlife Interface
• At all sites of cases, there was evidence
of wildlife habitation or denning adjacent
to human occupation of structures of
yards
• Frequently, a lot of debris (old cars, old
sheds, construction material, etc)
Ticks & Habitat
• Favorable habitat
– Deciduous forest
– Shrub layer
Ticks & Habitat
• Unfavorable habitat
– Open, dry habitats
– Conifer
(spruce/hemlock)
forests
Ticks & Habitat – Invasives
• Elias et al (2006) – Higher tick counts associated
with exotic invasive forest understory than native
forest understory or open understory forests.
Ticks & Hosts
White-tailed deer are THE
reproductive stage host
for deer ticks.
Abundant deer in presentday northeastern North
America
Deer and Deer Ticks
Each deer can
have up to 100
ticks at a time!
Each fed tick is
capable of
producing up to
3000 young!
Deer and Deer Ticks
500
400
2
R2 = 0.64
Ticks/Km
More deer =
the potential
for more ticks
(Rand et al.
2003).
300
200
100
0
0
10
20
30
Deer/Km2
40
50
Deer Reduction Studies -MA
-Wilson et al. 1988. Great
Island, MA
>2.3/km2 deer; significant
reduction of ticks
-Deblinger et al. 1993.
Ipswich, MA.
~7/km2 deer; one half the tick
abundance of pre-cull
numbers
-Rand et al. 2004.
Deer Reduction Studies - CT
-CT DEP 2007.
CT DEP
The Great Debate: Is it the Deer
or is it The Mouse??
• Mice – a reservoir host for
sub-adult (larvae and
nymphs) I. scapularis but
not the only host
– Chipmunks, squirrels and
birds also serve as reservoir
hosts
The Great Debate: Is it the Deer
or is it The Mouse??
• Deer – a key host for
adult I. scapularis perhaps the sole critical
wild host in the
northeast for tick
reproduction
– Dogs, cats, foxes
incidental
– Moose???
Islesboro Project – Community
Tick Mgmt
Table 1. Flagging effort, numbers of fall-flagged adult deer ticks (Ixodes scapularis ), positivity for Borrelia burgdoferi, the agent of Lyme
disease, and Anaplasma phagocytophilum , the agent of anaplasmosis, 2012.
Time Period
Site
Date
Fall 2012
Cliff Island, Portland
Islesboro
Long Island
Swan's Island
11/02/12
10/26/12
10/23/12
11/03/12
Spring 2012
Fall 2011
Flagging
Hours Ticks Ticks/hour
B. burgdorferi
Dissected Tested
+
%
A. phagocytophilum
Tested +
%
2.5
9.9
7.0
6.3
90
239
135
260
36.7
24.1
19.2
41.0
67
109
98
78
18
28
98
42
11
16
24
18
61.1
57.1
24.5
42.9
16
16
16
16
0
1
1
0
0.0
6.3
6.3
0.0
Swan's Island
05/15/12 18.8
97
5.1
92
92
24 26.1
53
3
5.7
Cape Elizabeth
Rockland
Pownal
Wells
1.3
3.7
1.3
1.6
82
13
22
135
65.6
3.5
17.6
82.6
79
11
14
90
79
11
14
90
42
7
7
60
53.2
63.6
50.0
66.7
Tick Control
•
•
•
•
Synthetic pesticide applications
‘Green’ options – botanicals
Habitat modification
Host reduction strategies
Tick Free Zones
When Removing A Tick:
•Prompt removal is
important!
•Grasp the tick with
tweezers close to the
skin.
•Pull gently but firmly
until the tick lets go.
Do not handle the
tick with bare hands
•Apply antiseptic to the
bite.
When Removing A Tick:
•Prompt removal is
important!
•Grasp the tick with
tweezers close to the
skin.
•Pull gently but firmly
until the tick lets go.
Do not use vaseline, alcohol
or matches to remove
ticks!
•Apply antiseptic to the
bite.
•
•
•
•
•
•
•
•
•
Hot pin
Butter
Vaseline
Baby oil
Drivers license
Expired credit card
Finger nails
Olive oil
Painting the tick with nail polish
•
•
•
•
•
•
•
•
•
Lit cigarette
Hot match
Butane lighters
Gasoline – kerosene
Liquid soap on a cotton ball
Spirits on cotton ball
Tools (pliers)
Peanut Butter
Fishing line
Tick Management Handbook
• A great resource on landscape planning
to reduce exposure to ticks.
• http://www.ct.gov/caes/lib/caes/documents
/publications/bulletins/b1010.pdf
Questions