Mosquitoes Test Positive for West Nile Virus Near Southwest Williamson County Regional Park

July 10, 2020 (Williamson County, TX) -- A sample of mosquitoes collected from a trap near the Southwest Williamson County Regional Park located in area of FM 1431 and CR 175 has tested positive for West Nile Virus. The testing is part of the Williamson County and Cities Health District’s (WCCHD) mosquito management program. The sample was collected on July 9, 2020, and the positive test was indicated in a lab result from the Texas Department of State Health Services lab in Austin and reported to WCCHD on July 10, 2020. The species that tested positive for West Nile Virus is Culex quinquefasciatus (southern house mosquito). This species has a flight range of about one mile.

Williamson County parks staff will continue mosquito control efforts with the treatment of standing water with larvacide, WCCHD will continue enhanced monitoring and testing, along with increased public outreach and education. Williamson County is prepared to take additional action if necessary. Due to the proximity to outdoor activities at Southwest Williamson County Regional Park and in several nearby neighborhoods, WCCHD is encouraging everyone to be especially vigilant about protecting themselves from mosquito bites when outdoors – and preventing mosquito breeding on their personal property.

There have been no reported human cases of West Nile Virus in Williamson County since 2017. West Nile Virus should not be confused with other mosquito-borne viruses. There has been no evidence of mosquitoes transmitting COVID-19.

What you can do

As part of its Fight the Bite campaign, the Health District recommends these mosquito safety precautions:
• Defend by using an EPA-approved insect repellent
• Dress in long sleeves and pants when outdoors, especially at Dusk and Dawn
• Drain standing water in flower pots, pet dishes, or clogged gutters so mosquitoes don’t have a place to breed and treat water that can’t be drained 

For more information, go to the WCCHD website at or visit the Texas Department of State Health Services West Nile website at For questions, email