West Nile virus detected in Elmore County mosquitoes

DHW Communications

Mosquitoes carrying West Nile virus (WNV) were detected in Elmore County on July 29, prompting health officials to remind people to take precautions to “Fight the Bite.” The positive mosquitoes, which are the first detected in Idaho this year, were collected by the Elmore County Mosquito Abatement District. Last year, Elmore County detected its first WNV-positive mosquitoes on July 27.

“The detection of West Nile virus-positive mosquitoes in Elmore County indicates that conditions are right for transmission of the virus to people,” said Dr. Leslie Tengelsen, state public health veterinarian. “This is the time of year when we typically start finding positive mosquitoes and reports of human and horse infections. We strongly encourage Idahoans to take measures against biting mosquitoes. these include wearing insect repellent and protective clothing and reducing standing water around gardens and homes where mosquitoes can lay their eggs.”

Last year, 14 Idaho counties reported WNV-positive people, mosquitoes, horses, or birds. WNV infections were reported in 16 people, 15 horses, and two birds; WNV contributed to two human deaths.

WNV is usually contracted from the bite of an infected mosquito; it is not spread from person-to-person through casual contact. Symptoms of infection can include fever, headache, body aches, nausea, and sometimes swollen lymph glands or a skin rash. Infection can result in severe illness, especially in people 50 years and older. If you feel ill, talk to your healthcare provider about testing for WNV.

To protect against WNV infection, people should avoid mosquitoes, particularly between dusk and dawn when mosquitoes are most active. In addition, everyone should:

  • Cover up exposed skin when outdoors and apply DEET or other EPA-approved insect repellent to exposed skin and clothing. Carefully follow instructions on the product label, especially for children.
  • Insect-proof your home by repairing or replacing screens. 
  • Reduce standing water around homes and properties. Check and drain toys, trays, and pots that are outdoors and can hold water.
  • Change bird baths, static decorative ponds, and animal water tanks weekly to reduce suitable mosquito habitat.

WNV does not usually affect domestic animals but can cause severe illness in horses and some species of birds. Although there is no vaccine for people, there are several vaccines for horses, which should be vaccinated annually.

For more information, please visit http://westnile.idaho.gov.

The Idaho Department of Health and Welfare is dedicated to strengthening the health, safety, and independence of Idahoans. Learn more at healthandwelfare.idaho.gov.