July 13, 2007

Health District Partners With Elmore County on West Nile Virus Efforts

Mosquitoes collected in traps in the Prairie and King Hill areas of Elmore County have tested positive for West Nile virus, according to test results released by the Idaho State Bureau of Laboratories. The positive mosquito pools are evidence that West Nile virus has returned to Elmore County again this year. Last year Elmore County had 66 reported human cases of West Nile virus, but no mosquito surveillance or abatement program. That changed this year due to a partnership with the Central District Health Department.

The Elmore County Mosquito Task Force and the health district are working together to determine where the mosquitoes carrying West Nile virus are in Elmore County so that abatement activities can be targeted in an effort to decrease the risk of West Nile virus exposure to humans. Central District Health is providing mosquito traps and other equipment as well as the personnel needed to conduct surveillance activities. Mosquitoes caught in the traps are separated by species and then sent to the state lab for testing. Test results are shared with Elmore County officials, allowing them to decide where to conduct mosquito control activities.

There are twelve trapping sites in Elmore County and the first mosquitoes testing positive for West Nile virus were found in a trap near the Prairie Community Center on June 30, 2007. Mosquitoes collected July 4th near King Hill also tested positive for West Nile virus.

"While the sample sizes were very small we now have confirmation that West Nile virus has returned to Elmore County." Said Marsha Sellers, Chair of the Elmore County Mosquito Task Force. "This is exactly the kind of information we've been waiting for to better inform our decisions on mosquito abatement efforts throughout the county."

Ideally mosquito abatement efforts try to kill the larvae before they reach adulthood and are able to fly. But the best method of mosquito control remains the elimination of the standing water they breed in. Sellers also said residents of Elmore County need to learn about West Nile virus and how to protect themselves from the disease.

West Nile virus is usually spread through the bite of an infected mosquito and is not generally spread from person-to-person or from infected animals to people. About 80 percent of people who are bitten by an infected mosquito will not become sick, but others may experience a mild, flu-like illness that can include headaches, body aches and a fever. Although rare, the virus can lead to serious illness, especially in people over the age of 50.

To protect themselves from mosquito bites people should:

• Insect-proof their homes by repairing or replacing screens;
• Reduce standing water on their property that provides mosquito breeding habitat, such as bird baths and decorative ponds;
• Cover up exposed skin when outdoors;
• Apply insect repellent approved by the EPA to exposed skin and clothing. Follow instructions on the product label, especially for children;
• Avoid mosquitoes when they are most active at dawn and dusk; and
• Report dead birds to your local Fish and Game office.

West Nile virus does not appear to affect most animals including dogs and cats, but can cause severe illness in horses and certain species of birds. Although there is not a vaccine available for people, there are several vaccines for horses. Approximately one-third of horses which contract West Nile virus will die, so horse owners are encouraged to contact their veterinarian about vaccinating their animals. Horse owners who suspect West Nile viral infection in their animal should contact their veterinarian immediately.

Additional information about the virus is available from the Idaho Department of Health and Welfare web site at www.westnile.idaho.gov or by calling the West Nile virus hotline 334-6500. Elmore County residents are also encouraged to report areas of concern using the Elmore County West Nile Hotline 1-866-884-2891.

More information on West Nile virus can be found here.