WEST
NILE VIRUS
INFORMATION
LINE FOR WASHINGTON STATE
1-866-788-4787
West
Nile Virus Information for Whatcom County – July 2006
West
Nile virus is a bird disease spread by mosquitoes, which sometimes
affects humans and certain animals, such as horses. Since 1999,
when the West Nile virus (WNV) was first documented in New York,
it has steadily moved westward across the country. It reached Whatcom
County in the fall of 2002 when test results from a symptomatic
horse in rural Whatcom County confirmed positive for WNV. Last summer,
WNV was detected in 1 horse, 1 dead bird, and 2 mosquito samples
in Washington State. There have not been any human cases of WNV
in our state, but it is anticipated that people may get the virus
this summer when mosquito populations grow. Washington is 1 of 3
states that has not yet had any confirmed human cases of WNV. It
is important to know that not all mosquitoes will carry the virus,
and only a few of the 20+ different species of mosquitoes found
in the state are competent vectors of the disease. Most people who
do become infected will not have any type of illness.
What
is the health risk from the West Nile Virus?
Although
the chances of a person getting WNV are small, all residents in
areas where the virus is active are at risk. Only about 1 in 5 people
who become infected will develop WNV symptoms, usually 3 to 14 days
after exposure. However, persons over 50 years of age and/or with
immune system deficiency are more at risk for getting symptoms than
children or pets. Mild symptoms may include fever, headache and
body aches, occasionally with a skin rash on the trunk of the body
and swollen lymph glands. Chances of developing severe symptoms
are about 1 in 150. The symptoms of a severe infection include headache,
high fever, neck stiffness, stupor, disorientation, coma, tremors,
convulsions, muscle weakness, and paralysis. In 2005, 3,000 cases
of the illness were reported across the United States, and of these
cases, 119 involved fatalities. Though the number of fatalities
is low compared to the number of reported cases of WNV, precautions
should be taken to reduce your risk. For more information on health
risks and common questions about West Nile Virus visit the Washington
State Department of Health web site.
Residents
can help reduce risk from the WNV
There
are some simple steps you can take to reduce your risk. The best
way to minimize the threat of WNV is to control mosquito populations
and prevent exposure to mosquitoes. To help control the mosquito
population, decrease mosquito habitat by emptying old tires, buckets,
plastic covers, toys and other containers around your home where
water can accumulate and serve as a breeding ground for mosquitoes.
Change water in birdbaths, fountains, wading pools and animal troughs
weekly. To protect yourself from mosquito bites, wear loose fitting,
long sleeved shirts, long pants and other protective clothing when
in mosquito-infested areas. You may also consider using a mosquito
repellant. For more information on preventing mosquito bites, visit
the following WSU link:
West
Nile Virus - Guidelines for Preventing Mosquito Bites
Why
should I worry about old tires and birdbaths, when there is a wetland
in my neighborhood?
One
type of mosquito, the Culex pipiens (AKA "the house
mosquito"), is of most concern due to their efficiency of transmitting
WNV when infected. Culex larvae grow in water filled containers
found around most homes. Tires are a particular problem because
they always hold water and the black color provides warmth. Any
object that holds stagnant water, except a chlorinated pool, can
produce thousands of mosquitoes. Healthy wetlands provide minimal
habitat for mosquitoes, because there are native fish, frogs, toads,
newts, salamanders and other predators of mosquitoes. For more information
on reducing mosquitoes at home, visit the following WSU link:
Guidelines
for Reducing Mosquitoes at Home
Mosquito
surveillance efforts of the Whatcom County Health Department
The
health department has begun its fourth year of implementing the
WNV Surveillance Program, which will continue where last year's
efforts left off. Last year, surveillance techniques were used to
locate mosquito breeding sites and areas of severe adult mosquito
activity. Mosquito collecting techniques included larvae dipping,
and dry ice baited adult mosquito trapping. These efforts contributed
to local, state and national databases by identifying the species
of mosquitoes in Whatcom County and documented the presence of competent
vectors of the West Nile virus. The Whatcom County Health Department
continues to work with other local agencies and businesses in the
county. There will be many public educational efforts made to help
local agencies identify breeding sites and basic mosquito larvae
identification. These surveillance techniques should help local
organizations decide if or what mosquito control efforts they need
to employ. For additional Whatcom County West Nile virus information,
visit Cooperative
Extension's West Nile virus home page.
What
is being done about Mosquito Control?
While
the Health Department has no specific authority to control mosquitoes,
we will encourage public and private landowners to evaluate their
mosquito situation. If there has been a history of mosquito problems
in certain areas, landowners in that area may need to take steps
to control mosquito larva. State permits are required to apply pesticides
to water. Therefore, some advanced preparation is needed before
pesticides can be applied. A streamlined permitting process has
been established by the Washington State Department of Ecology and
can be found with additional information at the following link:
Washington
Department of Health - Aquatic Mosquito Control General Permit
If
I see a dead bird, what should I do?
It
has been shown that the best indicator of WNV in a community is
a die off of crows, jays (corvids) and raptors. Although most birds
can be a reservoir of the virus, these types of birds are most affected
by the disease. WNV is not transmitted directly from the dead bird
to humans. We are interested in collecting information about dead
corvids and raptors as part of our surveillance efforts to identify
the presence of West Nile Virus in Whatcom County. If you find one
or more dead bird(s) in Whatcom County, call the Health Department
at (360) 676-6724 to report the location, condition of the bird
and date found. Health department staff will evaluate the information
you provide and will make a determination as to whether or not the
bird meets the criteria for testing. At that time we will explain
to you what to do with the bird. If the bird is not needed for testing
you can dispose of the bird in the trash. When handling any dead
bird, use gloves and wash your hands when finished. Place the bird
into a double plastic bag for disposal in your trash.
For
more information about WNV visit the following links:
CDC
- West Nile Virus Questions and Answers
WA
State Department of Health - West Nile Virus in Washington
If
you have any questions concerning West Nile Virus, please contact
the Health Department at (360) 676-6724.
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