The Vector/Mosquito Control program of the Environmental Health Division performs active mosquito surveillance by trapping mosquitoes and sending them to the Texas Department of State Health Services Arbovirus Surveillance Lab for testing. The lab conducts tests for multiple mosquito-borne viruses. For more information on the lab, click here Version Options West Nile Virus Information Headline. You can find a list of the 2024 Positive Mosquito Pools below.

West Nile Virus (WNV) is a disease primarily spread by Culex Quinquefasciatus mosquitoes. They become infected when feeding on infected birds, which circulate the virus in their blood for days. During later blood meals (when infected mosquitos bite), the virus may be injected into humans where it can multiply and possibly cause illness.

Infection with WNV can be either asymptomatic (no symptoms) in around 80% of infected people, or can lead to West Nile Fever or severe West Nile disease. About 20% of those who become infected with WNV will develop West Nile Fever. Symptoms include fever, headache, tiredness, body aches, nausea, vomiting and occasionally a rash. More severe symptoms (also called neuroinvasive disease) which can cause West Nile Virus Encephalitis or Meningitis, include high fever confusion, altered mental status, double vision, extreme fatigue, stiff neck, coma, tremors, and paralysis. WNV is not communicable from person to person, other than blood transfusion, organ transplant, breastfeeding, or perinatal transmission. Those infected with WNV are not viremic and are incapable of transmitting the virus to mosquitos.

The incubation period for WNV is typically 2 to 6 days but ranges from 2 to 14 days and can be several weeks in immunocompromised people. There are currently no vaccines or specific treatment for WNV. Most care is primarily supportive and taking measures to prevent secondary infections.

We at the Wichita Falls-Wichita County Health District are currently investigating all confirmed cases of WNV.  We encourage you to use personal protective measures which include use of EPA approved repellents, wearing long sleeved shirts and long pants, limiting outdoor exposure from dusk to dawn. Remember to also check for standing water and empty all that could be breeding grounds for mosquitoes.