Texas Department of State Health Services
NEWS RELEASE
July 2, 2007 DSHS Recommends Mosquito Precautions
With heavy rains and recent flooding in parts of Texas, the Texas Department of State Health Services (DSHS) recommends that people take precautions to avoid being bitten by mosquitoes.
Standing water is a breeding place for illness-causing mosquitoes.
DSHS offers these recommendations:
· Protect yourself with an appropriate insect repellent. Use insect repellents that contain DEET, picaridin or oil of lemon eucalyptus. Place insect repellent at the front and back doors of your home and apply before going outside.
· Mosquito-proof your house. Make sure door seals are secure and window screens are intact.
· Limit the amount of time you spend outdoors from dusk to dawn. These are times when the mosquitoes likely to carry infections are most active.
· Drain standing water from around your home. Empty cans, buckets, tires, rain gutters and flower pot bases regularly. Change the water in pet bowls, bird baths and wading pools several times a week.
Mosquito-borne illnesses include West Nile, St. Louis encephalitis, eastern equine encephalitis, western equine encephalitis and dengue fever. For more information visit the DSHS Web site, www.dshs.state.tx.us .
Avoiding Common Mosquito Bites Key in Preventing West Nile Infections
After years of promoting the chemical DEET as the best defense against West Nile-bearing mosquitoes, the 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 odor 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 percent 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 percent 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 odor 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 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 products provide four and six hours of protection, respectively, Proctor said.
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.
Avoiding Common Mosquito Bites Key in Preventing West Nile Infections
The name may sound exotic West Nile virus.
But it is the common backyard mosquito that is the troublemaker, the potential carrier of this and other infectious diseases. Most mosquitoes are simply an annoyance, but avoiding mosquito bites is the key to preventing illness.
We do not know the extent to which West Nile infections or the other mosquito-borne illnesses will affect Texans this year, said Jim Schuermann, staff epidemiologist for vectorborne and zoonotic diseases with the Texas Department of State Health Services (DSHS). But we do know that mosquitoes are a problem in every part of the state every year. And there are steps people can take to protect themselves.
At the top of the list is to use an insect repellent containing DEET, picaridin or oil of lemon eucalyptus. According to a 2003 DSHS survey, 77 percent of the people who got the most serious forms of West Nile infection never used repellent. This year the U.S. Centers for Disease Control and Prevention added picaridin and oil of lemon eucalyptus to the list of recommended repellent ingredients.
People should read and follow the label instructions, Schuermann said.
DSHS offers the following additional recommendations.
Drain standing water from around your home. Empty cans, buckets, tires, rain gutters, tree holes and saucers under potted plants regularly. Change the water in pet bowls, bird baths and wading pools several times a week. It only takes a thimble of water for mosquitoes to breed.
Limit the amount of time outdoors between dusk and dawn when those mosquitoes likely to carry infections are most active.
Dress appropriately when outside in mosquito-infested areas. Cover as much skin as possible to reduce exposure to mosquito bites and use a recommended repellent on exposed skin. Mosquitoes may bite through thin clothing, so spray clothes with repellent containing either DEET or permethrin for extra protection. Studies show that permethrin sprayed on clothing lasts through several washings.
Schuermann said it also is important to keep mosquitoes out of the house. Be sure door, porch and window screens are in good condition, he said.
West Nile virus and other mosquito-borne infections can result in serious illness or death. With West Nile virus, older people, especially those who already have medical problems, are most likely to develop the more serious forms of illness including encephalitis and meningitis, Schuermann said.
In 2004 West Nile was detected in 101 Texas counties. A total of 119 human cases of serious West Nile illnesses from 40 counties were reported, including eight deaths.
West Nile infection is caused by the bite of an infected mosquito that gets the virus when feeding on infected birds and other wild animals. It is not transmitted from person to person.
The risk of exposure to West Nile virus is relatively small. Not all mosquito species are able to transmit the virus. Of the species that do, only one in 100 mosquitoes will be infected; and only a small number of people bitten by infected mosquitoes will become sick. In general, out of 100 people infected with the virus, only 20 will develop any illness at all.
Symptoms usually appear from three to 14 days after a person is bitten. For most who do develop symptoms, the illness is relatively mild. The most common symptoms of mild infections include fever, headache, muscle aches and drowsiness. About one of 150 people infected with the virus will develop a severe form of the illness with symptoms that include intense headache, high fever, nausea, stiff neck, muscle tenderness, shivering and mental confusion. Convulsions, coma, and death may follow. For those who survive, recovery may take months.
For more information, go to:
The Center for Disease Control
Environmental Protection Agency
