Recent national news reports have described extensive West Nile virus activity in many localities across the country. Georgia has seen its share of cases as well, with 12 human cases already reported and more cases being evaluated. August and September are the peak months for human cases of West Nile virus in Georgia, so precautions need to be taken. The most effective way to avoid any of the mosquito-borne diseases is to avoid being bitten by mosquitoes. The effective use of insect repellents remains the best way to do this. The CDC recommends using products that contain active ingredients which have been registered by the EPA for use as repellents. The active ingredients DEET, picaridin, Oil of Lemon Eucalyptus or PMD and IR3535 have been shown to provide reasonably long-lasting protection from mosquitoes in scientific studies. The American Academy of Pediatrics recommends using products containing DEET with concentrations of 30% or less on children as young as 2 months of age. The other approved products are labeled for children above two years of age. Additional techniques for avoiding mosquito bites include wearing loose fitting, light colored clothing and making sure that all screens are in good condition around our homes.

The larval and pupal stages of mosquitoes require standing water to develop. Everyone should work to eliminate any form of standing water around their homes and neighborhoods. The Southern House mosquito, which is the primary vector of West Nile virus in Georgia, prefers to develop in nutrient-rich water in storm drains and catch basins. As a result, this mosquito actually does better during dry periods when heavy rains aren't flushing the storm drain systems in our communities. If mosquitoes are developing at a site and the water cannot be eliminated, there are a variety of EPA approved larvicides that are available. Some of these products can be purchased at local feed and seed and home improvement stores. As with all pesticides, follow the label instructions closely.

West Nile virus was first discovered in the U.S. in New York city in 1999. By 2001 it was found in Georgia and by 2002 it had spread across the country. Most people who are exposed to the West Nile virus do not develop any type of illness. An estimated 20 percent of the people who become infected develop West Nile fever: mild symptoms include fever, headache, and body aches, occasionally with a skin rash on the trunk of the body and swollen lymph glands. Symptoms of the mild form of WN virus generally last a few days. The symptoms of a severe infection (West Nile encephalitis or meningitis) include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. Symptoms of severe cases may last several weeks, although some neurological effects can be permanent. An estimated one in 150 persons infected with the West Nile virus will develop the more severe form of the disease. As we enter into the traditional peak season for West Nile virus transmission, we felt it was important to send a brief reminder of the importance of mosquito prevention and avoidance. Additional information is available at the Georgia Mosquito Control Association and the American Mosquito Control Association websites. The University of Georgia, Cooperative Extension Service thanks you for any assistance you can provide to your community to help reduce the risk of mosquito-borne disease.

Elmer Gray is a Cooperative Extension entomologist at the University of Georgia in Athens. He can be reached at ewgray@uga.edu.