The Washington State Department of Health
wants to inform you about tick-borne diseases and how to protect
yourself. By taking preventive measures to avoid tick bites, you and your family can safely enjoy Washington's
great outdoors. If bitten, it is important that you recognize
symptoms of a tick-borne disease and promptly seek medical attention.
Without early treatment, the effects of these diseases can be serious.
What
is a tick?
Ticks are blood-feeding parasites. Most
perch on the edges of low-lying vegetation and
wait for an unsuspecting animal host to brush against them, while some ticks
prefer to do their waiting in the comfort of the host's nest. Once
aboard, ticks crawl until they find a suitable spot to feed, then burrow
their
mouthparts into the skin for a blood meal. Ticks feed anywhere from several
minutes to weeks depending on their life stage, type of host, and
species of tick. Amazingly, their bodies slowly enlarge to accommodate
the amount of blood ingested. Engorged ticks can be many times their original
size as seen below. It is during feeding that infected ticks can
transmit disease to their hosts.
Ticks commonly found in Washington belong to one of three genera of
ticks, Dermacentor, Ixodes, and Ornithodoros.
- Dermacentor
species are found throughout the state. These ticks
prefer habitats such as woodland areas, medium height grasses and
shrubs between wetlands and woods, and sunny or open areas around
woods. Immature ticks feed primarily on small mammals,
particularly rodents, while the adults feed on deer, livestock,
dogs, and humans.
- Ixodes
species are mainly found in the western part of the state. They live in
heavily-forested or dense brushy areas, but not open areas. Preferred hosts for immature
ticks are birds and small mammals, primarily rodents. However
humans and dogs serve as good substitutes. For adults,
common hosts include livestock, dogs, and humans.
- Ornithodoros
species appear confined to the eastern part of the state. The
majority
of these ticks are nesting parasites preferring burrows and nests.
They usually feed
on rodents such as squirrels and chipmunks. Humans can be incidental
hosts when sleeping in cabins or dwellings inhabited with tick-infested
squirrels, chipmunks or other rodents.
What
diseases can ticks spread?
Close to 300 cases of tick-borne disease were confirmed in
Washington from 1989 to 2000. Overall, the
state has relatively few cases reported each year in comparison to some
areas of the United States. The tick-borne diseases
recognized in Washington are listed below. Also included in this list
are early symptoms of the disease and ticks responsible
for transmitting the disease. To learn more about a specific tick-borne
disease, click the name to view information available at the Centers
for Disease Control and Prevention.
| Disease
and Initial Symptoms |
Tick
Genus |
Rocky
Mountain Spotted Fever
- Sudden fever
- Headache
- Muscle pain
- Reddish-to-black rash
In Washington, one to two cases of Rocky
Mountain spotted fever occur each year. |
Dermacentor
|
Tick
Paralysis
- Fatigue
- Leg numbness
- Muscle pain
- Difficulty standing or
walking
Six cases of tick
paralysis have occurred in the state during 1989 through 2000. |
Dermacentor
and Ixodes |
Tularemia
- Fever
- Headache
- Swollen lymph nodes
- Skin ulcer near bite
Two to four cases of tularemia occur each year in
Washington.
|
Dermacentor |
Babesiosis
- Fever
- Chills
- Fatigue
- Muscle pain
- Anemia
Babesiosis is rare; only two cases have ever been reported
in Washington. |
Ixodes |
Lyme
Disease
- Fever
- Headache
- Stiff neck or neck pain
- Fatigue
- Slowly expanding
"bull's-eye" rash
In Washington, an average of 15 cases
occur each year.
|
Ixodes
|
Tick-borne Relapsing Fever
- Sudden fever
- Headache
- Nausea and vomiting
- Muscle and joint pain
- Reoccurring fever in 2-4
days
Four to eight cases of
relapsing fever occur each
year in Washington. |
Ornithodoros |
Please note that early symptoms of most tick-borne diseases mimic the
"flu" with fever, headaches, tiredness, and muscle pain.
How
can I avoid getting bitten?
When
working, camping, or walking in a tick habitat - wooded, brushy, or
grassy places - a few simple precautions can reduce your chance of being
bitten.
|
Wear
long pants and a long-sleeved shirt. Tuck your pant legs
into socks or boots and shirt into pants. This can help keep ticks on the
outside of your clothing where they can be more easily spotted and
removed.
|
|
| Wear
light colored, tightly woven clothing which will allow
the dark tick to be seen more easily. The tight weave makes it
harder for the tick to attach itself.
|
|
| Use
tick repellent when necessary, and carefully follow
instructions on the label. Products containing DEET or permethrin
are very effective in repelling ticks. Take special care when
using repellents on children.
|
| Check
yourself, your children and pets thoroughly for ticks.
Carefully inspect areas around the head, neck and ears.
Look for what may appear like a new freckle or speck of dirt.
|
|
In
northeastern Washington, a handful of cases of
Tick-borne Relapsing Fever occur each year. Most cases involve
individuals who have stayed at a summer cabin or vacation home. If you own a cabin
or vacation home in this region, follow these precautions to
avoid an encounter with Ornithodoros, the vector of relapsing
fever.
| Inspect
your cabin on a regular basis for signs of rodent
activity. |
| Eliminate
rodent nesting areas from your
cabin. |
| Use
food and waste-handling practices that eliminate food
sources for rodents.
|
Rodent-proof
your cabin as follows:
- Seal
all holes in foundation and walls.
- Place
heavy gauge metal screens on windows, vents, and other
openings to prevent entry of rodents.
- Place
an 18" perimeter border of gravel around the cabin. This
can help prevent the movement
of rodents and ticks into the cabin.
|
A good resource on integrated
management of ticks around your home is
Tick Management Handbook - An Integrated Guide for Homeowners, Pest
Control Operators, and Public Health Officials for the Prevention of
Tick-associated Disease, Connecticut Agricultural Experiment Station
(PDF 8.53MB).
What
to do if I am bitten?
If
you find a tick attached to your skin, promptly remove it. Grasp the
tick using tweezers as close to the skin as possible. With a steady motion, pull the tick
straight out. Do not twist or jerk. If
tweezers are not available, grasp the tick with a piece of tissue. Wash
your hands and apply antiseptic to the bite.
Occasionally,
mouthparts of the tick stay attached to your skin. The mouthparts
will not cause disease. If this happens, consult with your physician
about their removal.
Monitor
the bite and be alert for early symptoms
of tick-borne disease particularly "flu-like" symptoms or rash over the next
month or so. If you develop symptoms, contact your physician.
Who
can I contact for more information?
Should
you need additional information, please contact
Liz Dykstra of the
Washington State Department of Health at 360.236.3388.
