West Nile Virus

What is West Nile Virus?
West Nile Virus(WNV) is a mosquito- borne infection that can cause serious disease. WNV is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall.

What can I do to Prevent WNV?

The easiest and best way to avoid WNV is to prevent
mosquito bites.
  • Avoid the outdoors between dusk and dawn when mosquitoes are most active.
  • Dress with long sleeves and pants and cover as much skin as possible to reduce areas for mosquitoes to bite.
  • Use mosquito repellent that contain DEET, picaridin, IR3535, oil of lemon eucalyptus or paramenthane-diol and always follow product label instructions.
  • Eliminate standing water which serves as mosquito breeding areas:
    - Dispose of used tires, tin cans, plastic containers, ceramic pots or other water holding containers.
    - Drill holes in the bottom of recycling containers that are kept outdoors.
    - Turn over wading pools and wheelbarrows when not in use.
    - Change the water in bird baths twice weekly.
  • Repair window and doors screens to prevent mosquitoes from entering the house.
breedingsites.gif What Are the Symptoms of WNV?
  • Serious Symptoms in a Few People.
About 1 in 150 people infected with WNV will develop severe illness.The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors,convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks,and neurological effects may be permanent.

  • Milder Symptoms in Some People.
Up to 20 percent of the people who become infected will have symptoms which can include fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms can last for as short as a few days to as long as several weeks.

  • No Symptoms in Most People.
Approximately 80 percent of people who are infected with WNV will not show any symptoms at all, but there is no way to know in advance if you will develop an illness or not.

How Does West Nile Virus Spread?
  • Infected Mosquitoes.
WNV is spread by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread WNV to humans and other animals when they bite.
  • Transfusions, Transplants, and Mother-to-Child.
In a very small number of cases, WNV also has been spread directly from an infected person through blood
transfusions, organ transplants, breastfeeding and during pregnancy from mother to baby.
  • Not through touching.
WNV is not spread through casual contact such as touching or kissing a person with the virus.

How Soon Do Infected People Get Sick?
People typically develop symptoms between 3 and 14 days after they are bitten by the infected mosquito.

How Is WNV Infection Treated?
There is no specific treatment for WNV infection. In cases with milder symptoms, people experience symptoms such as fever and aches that pass on their own, although illness may last weeks to months. In more severe cases, people usually need to go to the hospital where they can receive supportive treatment including intravenous fluids, help with breathing, and nursing care.

What Should I Do if I Think I Have WNV?
Milder WNV illness improves on its own, and people do not need to seek medical attention for this infection though they may choose to do so. If you develop symptoms of severe WNV illness, such as unusually severe headaches or confusion, seek medical attention immediately. Severe WNV illness usually requires hospitalization. Pregnant women and nursing mothers are encouraged to talk to their doctor if they develop symptoms that could be WNV
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What Else Should I Know?
West Nile virus infects birds. In nature, West Nile virus cycles between mosquitoes and birds. Some infected birds can develop high levels of the virus in their bloodstream and mosquitoes can become infected by biting these infected birds. Some, but not all infected birds get sick and die of disease. If you find a dead bird: Don’t handle the body with your bare hands. Schuyler County Health Department is currently not taking dead birds.

West Nile Virus Surveillance Summary for Schuyler County
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*NY State DOH stopped reporting dead and live birds in 2009

NY State Surveillance Summaries

CDC National Surveillance Summaries

For more information on West Nile Virus, visit

CDC's West Nile Website

NY State Department of Health- West Nile Page