September 2, 2021 – A mosquito trap sample collected in the City of Granger has tested positive for West Nile virus. This testing is part of Williamson County and Cities Health District’s (WCCHD) Integrated Vector Management program. The positive test was indicated in lab results received on September 2nd from the Texas Department of State Health Services lab in Austin. City of Granger has coordinated for ground spraying planned to occur late evening on September 4th in Granger, weather permitting.

The positive sample was taken from a trap site near N. Colorado Street. The last date a positive sample was collected was August 24, 2021. This is the seventh reported West Nile virus positive trap of the 2021 season in Williamson County, and the sixth time this trap has tested positive this year.

Although the mosquito control product poses no significant health risk, if possible, people and pets may want to stay indoors during treatment. Treatment will occur along the street right-of-way and public parks. Spraying will not be conducted in the event of inclement weather.  

“As we continue to see mosquito samples test positive for West Nile virus in this area, it is strongly encouraged for residents to inspect their properties for standing or stagnant water to prevent mosquito breeding and remember to take appropriate precautions to prevent mosquito bites.” said Jason Fritz, MPH, Integrated Vector Management Program Lead at WCHCD.

What you can do:

Eliminating places where mosquitoes can breed and reducing the chances of mosquito bites are the most effective lines of defense against exposure to West Nile Virus. As part of its Fight the Bite campaign the Health District recommends the 3 Ds of mosquito safety:

  • Drain standing water in flowerpots, pet dishes, or clogged gutters so mosquitoes don’t have a place to breed and treat water that can’t be drained,
  • Defend by using an EPA-registered insect repellent, and
  • Dress in long sleeves and pants when outdoors.

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