The best way to prevent infection by the West Nile virus is to avoid being bitten by mosquitoes. People are urged to use mosquito repellents that have an active ingredient currently registered with the U.S. Environmental Protection Agency, such as Diethyltoluamide  (commonly referred to as DEET). Other approved active ingredients include picaridin and oil of lemon eucalyptus, according to the U.S. Centers for Disease Control and Prevention.

Products with between 10 percent and 30 percent DEET are often recommended. Repellent with a 10 percent concentration of DEET is effective for about two hours. Wearing repellent is especially important at dusk and dawn, when mosquitoes are most active.

Repellent should not be used on skin covered by clothing. In addition, products should not be sprayed directly onto the face. Instead, the product should be sprayed onto the hands and then applied to the face (avoiding the eyes and mouth). Repellent should not be sprayed onto skin that is irritated or cut. People are urged to stop using repellent if they develop a rash or an allergic reaction.

Products containing 10 percent or less of DEET are safest for children aged 2 to 12. Repellent should not be applied on the hands of children or used on infants under 2 months of age. Instead, the strollers and playpens of infants can be covered with mosquito netting.

Wearing long sleeves and pants reduces the amount of exposed skin on which mosquitoes may feed. However, mosquitoes can bite through thin clothing. Keeping well-maintained screens on windows and doors can help prevent mosquitoes from getting indoors.

Clothing, shoes, bed nets, camping gear and other products that contain the ingredient permethrin also can help ward off mosquitoes. Permethrin is a highly effective insecticide and repellent that continues to protect against mosquitoes, ticks and other arthropods (insects and insect-like animals with hard outer skeletons and jointed limbs) – even after repeated washings.

People can also reduce mosquito breeding grounds by removing any standing water collected in buckets, barrels, flower pots and other containers. Water in bird baths and pet dishes should be regularly changed (at least weekly), and holes should be drilled into tire swings to allow any water collected inside to drain out. Keeping children’s wading pools empty of water and resting on their sides can also help reduce potential breeding areas. Clogged gutters should be cleaned to prevent water from pooling.