What is West Nile Virus (WNV)?
WNV is a virus that can cause disease in people, birds, horses and sometimes
other animals. WNV is spread by mosquito bites. How do people get infected with
WNV? By being bitten by mosquitoes that are carrying the virus. Mosquitoes become
infected by feeding on birds that have the virus in their blood. Once a mosquito
is infected with the virus it can transmit the virus to humans, birds, horses
or other animals through a bite.
Can you get West Nile virus directly from people, birds or other animals?
WNV is NOT spread from person-toperson by touching or kissing a person who
is infected with the virus. There is no evidence that a person can get WNV by
touching a dead bird or other animal. However, it is a good idea for general
sanitary reasons that you wear gloves or use a shovel when handling any sick
or dead animals.
I’ve gotten a mosquito bite. Should I be tested for WNV?
No, only a small percent of mosquitoes carry WNV. See a doctor if you develop
the symptoms below.
What are the symptoms of WNV?
Most people bitten by an infected mosquito do not develop any symptoms. When
symptoms do occur, they usually appear about 3 to 14 days after being bitten.
The disease may be mild or serious. Mild illness includes fever, headache and
body aches. In a small number of cases, particularly among the elderly, the
disease can affect the central nervous system causing high fever, stiff neck,
muscle weakness, disorientation, brain inflammation (encephalitis), coma and
rarely, death.
Is there a treatment for WNV?
There is no specific treatment for WNV. Most people with mild illness recover
in a few days. In more severe cases, patients are treated with supportive therapy,
which can include hospitalization, intravenous fluids and respiratory support.
Using Insect Repellents Safely
For the longest lasting protection from mosquito bites, use insect repellent
products with no more than 20-30 percent DEET for adults and less than 10 percent
for children aged 2 years to 12 years. If you choose not to use DEET, products
containing soybean oil or eucalyptus oil have been found to be effective, but
must be applied more often because they do not repel mosquitoes for as long
as DEET*. In a recent study*, products containing citronella or Skin-So-Soft®
were NOT shown to be as effective, lasting on average only about 20 minutes
or less. Only adults should apply repellent on children. Only apply repellent
to exposed skin and clothing. Do not use repellent under clothing. Do not apply
repellent over cuts, wounds, sunburn or irritated skin. Spray repellent on your
hands in order to apply it to your face. Don’t apply repellent to your
eyes or mouth. Wash off repellent daily and reapply as needed.
*New England Journal of Medicine, July 4, 2002
Control Mosquitoes by:
- Make sure doors and windows have tight-fitting screens.
- Repair or replace screens that have tears or holes.
- Dispose of tires, buckets, ceramic pots, plastic containers or similar water-holding
containers.
- Keep water-holding unit in swamp coolers clean.
- Tightly cover cisterns, septic tanks and all water storage containers.
- Clean rain gutters regularly.
- Empty and wash birdbaths and wading pools weekly.
- Clean and chlorinate swimming pools; drain water from pool covers.
- Stock garden ponds with goldfish or mosquito fish; they eat the mosquito
eggs and larvae.
- Remove weeds and brush that provide resting places for adult mosquitoes.
- Properly grade surface-irrigated fields. Do not over-irrigate your fields
and pastures.
- Clean vegetation and debris from canals, ditches, laterals and drains.
