Tarrant County Public Health confirmed its first West Nile Virus-positive mosquito samples of 2026, marking the start of the county’s West Nile season.
First Positive Samples Of 2026
The samples came from Fort Worth and Grand Prairie during routine countywide mosquito surveillance, according to a May 14 public health release.
Tarrant County has tested 314 mosquito samples so far this year through Tarrant County Public Health’s North Texas Regional Laboratory.
Tarrant County has not reported any human cases so far this season.
Last year, Dallas County Health and Human Services confirmed its first positive West Nile mosquito pools on June 1, 2025, in Irving, Richardson, and Rowlett, as previously reported by The Dallas Express.
County officials said West Nile Virus activity typically increases from May through October as warmer weather leads to more mosquito activity. Local cities and unincorporated areas of Tarrant County may conduct mosquito treatments as needed.
How North Texas Tracks Mosquitoes
Tarrant County Public Health maintains an ongoing mosquito surveillance and mitigation program that collects mosquitoes from traps placed across county cities. The county says the program uses more than 150 mosquito traps.
Dallas uses a similar mosquito-control approach. The City of Dallas says its program includes weekly mosquito trapping and collections, monitoring known breeding sites, applying larvicide, responding to standing-water complaints, stocking Gambusia minnows in standing water that cannot be emptied, and treating storm drains in areas identified through surveillance.
Dallas has not announced a 2026 first positive West Nile mosquito sample as of the latest available public information reviewed by The Dallas Express. The City of Dallas, however, says it conducts weekly mosquito trapping and collections as part of its mosquito-control program.
The City of Dallas also maintains a “Do Not Ground Spray List” for residents who do not want ground spraying. Residents must submit a 311 request and sign up each season to remain on the list.
How West Nile Spreads
West Nile Virus commonly spreads to humans through the bite of an infected mosquito.
Most infected people do not develop symptoms. Some may develop fever, headache, body aches, vomiting, diarrhea, or rash, according to public health guidance.
Severe illness can affect the central nervous system and may result in hospitalization or death.
No licensed vaccines or medicines are available to prevent or treat West Nile Virus disease in people.
Remember The Four Ds
The City of Dallas advises residents to remember the Four Ds to reduce mosquito exposure:
- Drain: Drain or treat standing water in and around homes and workplaces
- Dusk/Dawn: Limit outdoor activities during dusk and dawn, when mosquitoes are most active
- Dress: Wear long, loose, and light-colored clothing outside
- DEET: Use insect repellents that contain DEET or other EPA-approved repellents and follow label instructions
Standing water can collect in swimming pools that are not kept clean, ponds, pet dishes, birdbaths, potted plants, old tires, empty containers, toys, and clogged rain gutters, according to the City of Dallas.
Tarrant County Public Health also advises residents to keep vegetation trimmed because thick bushes and plants can provide resting places for mosquitoes.
The reminder comes as the Metroplex faces several rain and thunderstorm chances this week, which could leave standing water in yards, gutters, containers, and other mosquito breeding sites.
