CDC Identifies New Encephalitis Virus in New York State
State Health Department Provides Insect Repellent for Distribution in Counties at Risk from West Nile–Like Virus
Albany, September 24 – The United States Centers for Disease Control and Prevention (CDC) today informed health officials in New York State that several bird specimens submitted from the State were infected with a virus that most closely resembles West Nile virus.
West Nile virus has never before been identified in the United States, or anywhere in the Western Hemisphere. How it arrived in New York State is not known.
CDC is not able to confirm whether the West Nile–like virus, which is sometimes referred to as "Old World St. Louis encephalitis" is the cause of the bird deaths. The dead birds included two flamingos and an Asian pheasant from the Bronx Zoo, and a crow submitted by a wildlife pathologist from the New York State Department of Environmental Conservation. Reportedly, the dead crows came from Scardsdale, Westchester County. Other dead crows have been identified from counties surrounding New York City.
Health officials are investigating whether the bird deaths are associated with an encephalitis epidemic that has produced illness in New York City and Westchester County. Both areas currently are undertaking mosquito control measures as a result of the outbreak of what has been identified as St. Louis encephalitis (SLE). CDC officials say they will perform additional laboratory tests to determine if patients who were diagnosed with SLE, or who had encephalitis symptoms, but whose illness was not confirmed as SLE, were infected with West Nile–like virus.
Clinical symptoms for encephalitis caused by West Nile–like virus are similar to those caused by SLE. West Nile virus is transmitted by Culex pipiens and Anopheles mosquitoes which are active mainly from dusk to dawn. The virus is also carried by the Aedes vexans mosquito. Aedes vexans is active during the day as well as night.
State Health Commissioner Dr. Antonia C. Novello is advising people who live in counties which have had cases of SLE diagnosed, or in areas which have experienced unusual numbers of crow deaths to take precautions to avoid being bitten by mosquitoes. These include:
- Eliminate any items that may collect standing water that provides a mosquito–breeding area from your premises;
- Wear long sleeve shirts and long pants if you are spending time outdoors in likely mosquito habitats such as woods or wetlands; and
- Use an insect repellant containing DEET, according to label instructions, if you will be spending time outdoors (DEET fact sheet follows).
According to the CDC, the mosquito control measures currently being taken by New York City and Westchester County are appropriate in response to both St. Louis encephalitis and the West Nile virus. Individuals who find dead birds should not touch them with their bare hands. Wear gloves; double–bag the birds and dispose of them in the trash.
At the direction of Governor George Pataki, other New York State agencies, including the Department of Environmental Conservation and the State Emergency Management Office (SEMO) are assisting with the encephalitis investigation. Individuals who have questions about mosquito–borne encephalitis should contact their county health department.
Deet Tips: Protecting Yourself With Deet and Protecting Yourself From Deet
The chemical N,N–diethyl–m–toluamide –– more commonly known as DEET –– is an insect repellent that can prevent mosquito bites but must be used with caution. The New York State Department of Health recommends taking these precautions when using repellents containing DEET:
- Store bottle out of the reach of children and read all instructions on label before applying.
- Do not let children apply DEET themselves.
- Avoid prolonged and excessive use of DEET. Use sparingly to cover exposed skin; do not treat unexposed skin.
- Do not apply repellents in enclosed areas or directly on face.
- DEET can be applied to clothing, but may damage some synthetic fabrics and plastics.
- Wash treated skin and clothing after returning indoors.
- If you believe you are having an adverse reaction to a repellent containing DEET, wash the treated area immediately.
- Remember that the use of DEET alone is not enough to eliminate risk of mosquito bites. Take other precautions –– such as wearing long pants and long sleeve shirts. Also, eliminate items on your premises where standing water can collect and serve as a mosquito breeding ground.