West Nile Virus - Prevention

Prevention

Personal protective measures can be taken to greatly reduce the risk of being bitten by an infected mosquito:

• Using insect repellent on exposed skin to repel mosquitoes. EPA-registered repellents include products containing DEET (N,N-diethylmetatoluamide) and picaridin (KBR 3023). DEET concentrations of 30% to 50% are effective for several hours. Picaridin, available at 7% and 15% concentrations, needs more frequent application. DEET formulations as high as 50% are recommended for both adults and children over 2 months of age. Protect infants less than 2 months of age by using a carrier draped with mosquito netting with an elastic edge for a tight fit.
• When using sunscreen, apply sunscreen first and then repellent. Repellent should be washed off at the end of the day before going to bed.
• Wear long-sleeved shirts which should be tucked in, long pants, and hats to cover exposed skin.
• The application of permethrin-containing (e.g., Permanone) or other insect repellents to clothing, shoes, tents, mosquito nets, and other gear for greater protection. Permethrin is not labeled for use directly on skin. Most repellent is generally removed from clothing and gear by a single washing, but permethrin-treated clothing is effective for up to 5 washings.
• Be aware that most mosquitoes that transmit disease are most active during twilight periods (dawn and dusk or in the evening). A notable exception is the Asian Tiger mosquito which is a daytime feeder and is more apt to be found in, or on the periphery of, shaded areas with heavy vegetation. They are now widespread in the United States and in states such as Florida they have been found in all 67 counties.
• Staying in air-conditioned or well-screened housing, and/or sleeping under an insecticide treated bed net. Bed nets should be tucked under mattresses and can be sprayed with a repellent if not already treated with an insecticide.