State Announces Changes in West Nile Virus Surveillance for 2003

Wednesday, April 16th 2003, 12:00 am
By: News On 6

West Nile virus made its official entrance into Oklahoma last year and state health officials are already gearing up their prevention and control efforts for 2003.

"Although it is too early in the year for the mosquito population that transmits West Nile virus to be active in Oklahoma, we are encouraging the public to begin now to get in the habit of conducting mosquito control efforts around their homes and businesses," said State Public Health Veterinarian Dr. Kristy Bradley.

Nearly 3,000 dead birds were tested for the virus in 2002, at a cost of more than $100,000. Since last year's surveillance has already confirmed the presence of West Nile virus from border to border in the state, state health officials say that 2003 resources will be directed toward prevention and control of the disease rather than intensive surveillance.

"The statewide toll-free phone number to report dead birds will not be routinely utilized this year. Instead, we are asking the public to report dead bird sightings, specifically dead crows, blue jays, and raptors (hawks, owls, or eagles) to their local county health department," Bradley said. Local county health officials will track these reports, but West Nile testing of dead birds will be limited to communities in 19 counties that have an operational mosquito control program, such as a larvicide treatment program or spraying for adult mosquitoes. Those counties include Beaver, Caddo, Carter, Cleveland, Comanche, Jackson, Kay, LeFlore, McIntosh, Muskogee, Oklahoma, Okmulgee, Ottawa, Pittsburg, Sequoyah, Texas, Tulsa, Wagoner, and Washington. Confirmatory testing of birds in these locales only will be used to guide mosquito control efforts in local communities.

State health officials say the public should begin now to "fight the bite" and get in the habit of conducting activities that will prevent the growth of mosquito populations around their homes and businesses. Mosquito control tips include the following:

Prevent items such as buckets and tarps from holding standing water.

If rainwater is collected, cover and seal containers when not collecting rain.

Rinse, scrub, and refill birdbaths weekly.

Empty plastic wading pools weekly and store indoors when not in use.

Properly maintain swimming pools.

Store boats covered or upside down.

For a water garden or ornamental body of water, use an environmentally safe product to kill the larvae, or stock with fish that eat mosquito larvae.

Regularly clean fallen leaves and debris from roof gutters.

Trim grass and weeds and dismantle brush to deprive mosquitoes of a habitat.

Repair or replace broken or torn window screens.

West Nile virus can infect humans, birds, mosquitoes, horses and some mammals. It is spread through the bite of an infected mosquito, usually the Culex mosquito. These mosquitoes pick up the virus when they feed on infected birds. The virus is then transmitted to animals and humans when bitten by the mosquito. Culex mosquitoes are most active in Oklahoma from July through October.

Later this summer as the Culex mosquitoes become active, persons are advised to apply a DEET-based mosquito repellent to their exposed skin and clothing. DEET contains the chemical N,N-diethyl-m-toluamide, which repels the mosquito, making the person unattractive for feeding.

Last year marked the largest epidemic of West Nile virus ever recorded in the United States with more than 4,000 human cases reported. 21 human cases, with two deaths, were confirmed in Oklahoma through laboratory diagnosis. Those persons 50 years of age and older are at greatest risk from developing the severe health consequences of West Nile virus, such as encephalitis and meningitis. Most persons who become infected with West Nile virus, however, develop only a mild flu-like illness or will not have any symptoms.

For more information about West Nile virus, visit the following Web sites: Oklahoma Department of Health and Centers for Disease Control