Tarrant County Public Health officials confirmed this year’s first positive test samples for West Nile Virus.
The samples were collected in Fort Worth and Grand Prairie. As of May 14, 314 mosquito samples have been tested this year at Tarrant County Public Health's North Texas Regional Laboratory.
Tarrant County’s West Nile Virus season started around the same time last year. In 2025, there were a reported 127 cases in Texas and 2,076 nationwide. The virus, which has been endemic to the Lone Star State since 2002, typically sees an increase in cases from May to October as warmer weather leads to heightened mosquito activity that lingers into the fall.
There are no vaccines to prevent a West Nile Virus infection nor medicines to treat the virus in people, according to the Centers for Disease Control and Prevention. About 1 in 5 individuals who contract the virus experience symptoms, which include fever, body aches, headaches and joint pain. Symptoms of the most serious cases, known as neuroinvasive disease, include disorientation, muscle weakness, tremors, paralysis and death.
No human cases have been reported in 2026, according to Tarrant County Public Health.
The announcement comes on the heels of officials informing Tarrant County commissioners that the public health department plans on continuing surveillance practices in advance of the World Cup’s kickoff in June.
Sabrina Vidaurri, associate director of health protection and response at Tarrant County Public Health, told commissioners on May 12 that the county tests mosquito samples for West Nile Virus and St. Louis encephalitis, but abatement programs are run by the 36 cities the county works with.
Tarrant County began using heavy larvicide last year to kill mosquito larvae, Vidaurri noted.
“The best way to protect yourself from mosquitos is to reduce the breeding cycle,” Vidaurri said to commissioners.
The public health department also purchased $20,000 worth of mosquito dunks for participating cities, Vidaurri said.
The last West Nile Virus death in Tarrant County was in 2024, when the county saw 28 positive cases in humans, involving 24 hospitalizations.
Tarrant County saw at least one human case of West Nile Virus last year, according to the Texas Department of State Health Services. Despite providing an exact number of human cases in previous years, Tarrant County Public Health did not share case numbers in 2025.
The department recommends residents take steps to prevent mosquito bites and eliminate breeding sites around their homes by:
- Applying EPA-approved insect repellant.
- Wearing loose-fitting long sleeved clothes and pants.
- Removing or treating standing water around your home with larvicides.
- Staying indoors during peak mosquito activity hours, like dawn and dusk, when possible.
Ismael M. Belkoura is the health reporter for the Fort Worth Report. His position is supported by a grant from Texas Health Resources. Contact him at ismael.belkoura@fortworthreport.org.
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