West Nile Virus 3/22/2010
What is the West Nile Virus?
According to the Center for Disease Control, the West Nile Virus is a virus commonly found in Africa, West Asia, and the MiddleEast. It is closely related to St. Louis encephalitis virus which is also found in the United States. The virus can infecthumans, birds, mosquitoes, horses and some other mammals.
The main route of human infection with West Nile Virus is through the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds, which may circulate the virus in their blood for a few days. The virus eventually gets into the mosquito's salivary glands. During later blood meals (when mosquitoes bite), the virus may be injected into humans and animals, where it can multiply and possibly cause illness.
In the 1999 New York area epidemic, there was a large die-off of American crows. Since then, West Nile virus has been identified in more than 200 species of birds found dead in the United States. Most of these birds were identified throughreporting of dead birds by the public. Check with your local health department for instructions on reporting and disposing of a dead bird. If you need to pick up a dead bird, or local authorities tell you to simply dispose of it, avoid bare-handed contact with any dead animals, and use gloves or an inverted plastic bag to place the bird carcass in a garbage bag and dispose of it with your routine trash.
Infection in humans with West Nile Virus can be asymptomatic (no symptoms), or can lead to West Nile fever or severe West Nile disease. It is estimated that about 20% of people who become infected with West Nile Virus will develop West Nile fever. Symptoms include fever, headache, tiredness, and body aches, occasionally with a skin rash on the trunk of the body and swollen lymph glands. While the illness can be as short as a few days, even healthy people have reported being sick for several weeks. It is estimated that approximately 1 in 150 persons infected with the West Nile virus will develop a more severe form of disease. Serious illness can occur in people of any age, however people over age 50 and some immuno-compromised persons (for example, transplant patients) are at the highest risk for getting severely ill when infected with West Nile Virus. Most people, about 4 out of 5, who are infected with West Nile virus will not develop any type of illness (an asymptomatic infection), however you cannot know ahead of time if you'll get sick or not when infected.
It is not known how long the West Nile Virus has been in the U.S., but the Center for Disease Control scientists believe the virus has probably been in the eastern U.S. since the early summer of 1999, possibly longer. The continued expansion of West Nile virus in the United States indicates that it is permanently established in the Western Hemisphere. In 2005, there were 2,819 cases of West Nile Virus reported to the Center for Disease Control for the United States. Of those cases, 105 resulted in death.
Mosquito Control Information
Precautions to avoid mosquito bites include:
- Minimize time outdoors at dusk and dawn
- Be sure door and window screens are tight fitting and in good repair
- Wear shoes, socks, long pants, and long-sleeved shirts. Clothing material should be tightly woven
- Use mosquito netting when sleeping outdoors
- Consider using mosquito repellent when it is necessary to be outdoors and always use them according to label instructions
- When using DEET (the most widely used insect repellent) on children, use a product containing less than 10% DEET and wash treated skin after returning indoors
Measures to reduce mosquitoes around the home include:
- Dispose of water-holding containers, such as ceramic pots, used tires, tire swings
- Drill holes in the bottom of containers such as those used for recycling
- Clean clogged roof gutters
- Turn over objects that may trap water when not in use, such as wading pools and wheelbarrows
- Change water in bird baths on a weekly basis
- Clean and chlorinate swimming pools, and when not in use, use a pool cover
- Use landscaping techniques to eliminate areas where water can collect on your property
Get More Information, Report Dead Birds, or Find Out How to Contact Your Mosquito Abatement District
Call the 2-1-1 Idaho CareLine by dialing 2-1-1 or 1-800-926-2588 to get the contact information of your local Idaho Department of Fish and Game office to report dead birds. You can also call 2-1-1 to get the contact information for your local Mosquito Abatement District (MAD).