The reported annual number of U.S. Lyme disease cases tripled from 1992 to 2009, with children most at risk for the disease, federal health officials say.
Officials at the Centers for Disease Control and Prevention say Lyme disease is transmitted to people through the bite of infected blacklegged ticks -- most active during May through July. About 95 percent of reported cases in 2009 were from just 12 states -- Pennsylvania, New Jersey, New York, Massachusetts, Connecticut, Wisconsin, Maryland, Minnesota, New Hampshire, Delaware, Maine and Virginia.
Nearly 30,000 confirmed cases of Lyme disease were reported in 2009. To prevent Lyme disease and other tickborne diseases, the CDC recommends people:
-- Avoid areas with high grass and leaf litter and walk in the center of trails when hiking.
-- Use repellent that contains 20 percent or more DEET on exposed skin. Parents should apply repellent to children; the American Academy of Pediatrics recommends products with up to 30 percent DEET for kids.
-- Use products that contain permethrin to treat clothing and gear, such as boots, pants, socks and tents, or look for clothing pre-treated with permethrin.
-- Conduct a full-body tick check using a hand-held or full-length mirror to view all parts of your body upon returning from tick-infested areas.
Anyone who develops a fever or a rash after being bitten by a tick or spending time in tick-infested areas should seek prompt medical care. Infection can spread to joints, the heart and the nervous system if Lyme disease is left untreated, the CDC says.