DEET guidelines make for a safe summer

The judicious use of repellents containing low levels of the chemical can help patients ward off insect-borne diseases.

By Susan J. Landers, AMNews staff. June 16, 2003.

Washington -- It's mosquito and tick season, and patients are swarming to their physicians' offices with questions about how to protect themselves from insect-borne illness.

Unless these patients opt to cover up from head to toe or remain indoors until late fall, the use of an insect repellent is probably a necessity. And those that contain DEET are likely the best choice, experts agree.

DEET "protects longer and is effective against more species of flying and crawling insects than other repellents," said Mark Fradin, MD, a dermatologist in private practice in Chapel Hill, N.C., and author of "Mosquitoes and Mosquito Repellents: a Clinician's Guide," Annals of Internal Medicine, June 1, 1998.

The main questions doctors may hear from their patients are: Do I need an insect repellent? Is DEET really safe? And, how much is too much?

Need is all too apparent. The Centers for Disease Control and Prevention receives reports annually of nearly 10,000 cases of Lyme disease and 1,000 reports of encephalitis.

Plus, there have been 3,893 human cases of West Nile virus in the United States in the last few years, with 254 deaths resulting. States are bracing for more as this year's mosquito season gets underway. Epidemiologists predict that the virus will spread to all 48 contiguous states.

With the discovery that more mosquito species are capable of transmitting West Nile virus, the CDC now recommends applying a repellent before spending much time outdoors, whether day or night.