Mosquitos have typically been a nuisance, causing a bothersome itch
and a small welt. In the vast majority of cases, the mosquito bite
would be gone and forgotten in a day or two. But a small number of
mosquito species have been confirmed as potentially presenting more
than a nuisance. They may carry West Nile Virus.
The “good” news about WNV is that approximately 80% of
infections are asymptomatic; there are no apparent symptoms or adverse
reactions. In addition, about 20% of infections result in West Nile
Fever. These symptoms are generally characterized by nausea, vomiting,
headache, myalgia and last 3 to 6 days. The remainder of infections,
less than 1% results in severe neurological disease. The mortality
of WNV cases is less than 0.1%, or less than 1 in 1000.
WNV is harbored in the bird population. Mosquitoes, by way of biting
an infected bird, can contract the virus and hold it in their salivary
glands. The concern is that WNV may then be transferred to humans
as the mosquito “bites” in seeking a blood meal.
Dead birds can be the first indication of WNV in a community. The
Mid-Ohio Valley Health Department conducts dead bird surveillance
in all six of its counties. Individuals can contact the sanitarian
in their county concerning submittal of dead birds for testing. Information
concerning the dead bird is evaluated to ensure the condition of the
bird makes it a viable specimen for submission.
The surveillance program is not limited to shipping birds for testing.
From May through September, the agency accepts and records dead bird
information by phone. The information is consolidated weekly and forwarded
to the Infectious Disease Epidemiology Program at the WV State Health
Department. Data is analyzed for unusual numbers of dead birds reported,
types of birds being reported, and specific location information.
Last year, the state encountered its first confirmed WNV bird in
Jackson County, its first confirmed human WNV case in Putnam County,
and its first WNV associated death in Wood County.
While 2002 saw West Nile emerge in West Virginia, the virus has existed
for many years. It was first detected in 1937 in a female in the West
Nile District of Uganda. In 1957, the first epidemiological ‘outbreak’
of the virus was documented in Israel. The first finding of WNV in
the US was in 1999 in New York. Last year saw over 4000 WNV cases
reported in 39 states. There were 277 deaths associated with West
Nile Virus. And the virus is not human-specific. While the list of
affected wild and domesticated animals continues to grow, crows, blue-jays
and horses have experienced high mortality rates.
The Mid-Ohio Valley Health Department encourages individuals to exercise
the “3 R’s” in preventing exposure to West Nile
Virus.
1 – Reduce – Mosquitoes search for areas of standing
water in which to lay their eggs - tires, flower pots, gutters, low
lying areas that persistently hold water, even pop bottle caps. Failure
to eliminate these sources can provide for ideal breeding sites. Reducing
and eliminating these sites has a significant effect on mosquito breeding.
Where standing water cannot be eliminated, a biological larvacide
containing “Bti” can be applied following manufacturers
instructions.
2-Repel – Exposure to mosquitoes can be minimized by wearing
long-sleeved clothing and using repellant containing DEET. However,
it is imperative to follow the manufacturers’ instructions for
application. Younger children may transfer the repellant to their
eyes and mouth via their hands.
3-Recognize – Be aware of times with increased exposure to
mosquitoes. Mosquitoes are generally more active at dawn and at dusk.
Camping, being in the woods, and other outdoor activities increase
potential exposure. Recognize those times and utilize proper attire
and protective measures.
West Nile Virus is an emerging disease in the United States with
a very brief history. Its adverse affects, while very unlikely, can
be debilitating. However, exercising sound personal protective measures
with the 3 R’s can significantly decrease the potential for
exposure..
For questions concerning the West Nile Virus, visit the Mid-Ohio
Valley Health Department website at www.movhd.com
or contact the local MOVHD office.
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