Atlanta After years of promoting the chemical DEET as the best defence against West Nile-bearing mosquitoes, the U.S. government for the first time is recommending the use of two other insect repellents.
Repellents containing the chemical picaridin or the oil of lemon eucalyptus offer “long-lasting protection against mosquito bites,” the Centers for Disease Control and Prevention said, adding that repellents with DEET remain on the agency's recommendation list.
“Since West Nile virus is present across the entire country at this point and it's here to stay, we constantly need to be vigilant,” said Dr. Lyle Petersen, director of the CDC's division of vector-borne infectious diseases. “It gives consumers a better option to protect themselves.”
Both products have been available elsewhere in the world, including Europe and Australia, since the 1980s. Repellent makers have been eager to introduce them to U.S. markets but it was hard to compete with DEET, the only chemical touted as effective by local, state and federal health officials.
Federal officials maintained for years that non-DEET repellents were not likely to offer the same degree of protection from mosquito bites. DEET has been the go-to chemical for health officials trying to control the spread of the West Nile virus in the United States.
However, recent studies prompted CDC officials to broaden the recommendations. The CDC says picaridin is “often comparable with DEET products of similar concentration” and oil of lemon eucalyptus provides protection time “similar to low-concentration DEET products in two recent studies.”
Consumers tend to like picaridin repellents because they are more pleasant to the skin and don't have the odour that DEET repellents have. And oil of lemon eucalyptus is a natural ingredient, which appeals to those who don't like the thought of putting chemicals on their skin, said Angela Proctor, a product manager for the Cutter line of insect repellents by Spectrum Brands.
Nationwide, only about 40 per cent of people use insect repellents. In Pacific coast states such as California — the state with the highest number of cases (771 cases, 23 deaths) last year — only 23 per cent use insect repellent, said Emily Zielinski-Gutierrez of the CDC.
“That's a lot of people who are going out there unprotected,” she said.
Users complained of DEET's odour or said it feels unpleasant on the skin. DEET repellents also have reportedly damaged plastics and fake fingernails. Other people have speculated it could cause brain damage, although the U.S. Environmental Protection Agency said the chemical won't cause harm if used properly.
“There's a certain segment of the population that no matter how safe you tell them DEET is . . . there's a hesitancy to use DEET,” said Richard Falco, a Fordham University medical entomologist. “You can do so much to tell people what to use but if they're not using it you have to go to something else. I think this will have a positive impact on public health.”
DEET was developed by the U.S. Department of Agriculture in 1946 and has been registered with the Environmental Protection Agency as an approved active ingredient since 1957.
Various levels of DEET appear in the popular Off lines by S.C. Johnson & Son Inc., including Deep Woods and Skintastic. Other brands such as Repel and BugOff have lately launched products without DEET.
Spectrum Brands introduced a picaridin-based repellent in January — Cutter Advanced — and it has been marketing a repellent with oil of lemon eucalyptus since 2002.
The CDC said it still will promote other personal protection measures, such as wearing long-sleeved clothing while outside and disposing of containers of water that could be breeding grounds for the flying insects.
West Nile virus first arrived in 1999 in New York. Last year there were 2,470 cases and 88 deaths. The highest number of U.S. cases came in 2003, when 9,682 people were infected and 264 died.