Harris County health officials warn of early West Nile mosquitoes

Mosquito traps in north and northwest Harris County turned up West Nile in January, with positive samples in ZIP codes 77041 and 77032, a sign the virus was circulating far earlier than many residents expect. By May 19, Texas health officials had confirmed the state’s first human case of 2026 in a Harris County resident, and the diagnosis was the severe neuroinvasive form of the disease. County health leaders have since kept surveillance tight and urged households to take the warning seriously before summer peaks.

The early detections matter because West Nile is not just a seasonal nuisance in a county as large and wet as Harris. Texas has logged 976 West Nile cases and 106 deaths in the last five years, including 57 deaths in 2024 and 9 in 2025, a reminder that one active season can turn dangerous quickly. In Harris County, the January mosquito hits and the May human case suggest this year’s risk arrived ahead of the usual summer surge, not after it.

Health officials have already responded with targeted evening spraying around the affected areas, while county teams continue checking traps across the county for new positive pools. That kind of early response is only part of the equation, though. West Nile can spread when infected mosquitoes find standing water and easy access to people, so the county’s pace will depend on whether surveillance, spraying and resident cleanup stay ahead of the virus as temperatures rise.

The most effective protection starts at home this week. Drain water from flowerpots, buckets, kiddie pools, pet bowls and clogged gutters. Wear long sleeves and pants outdoors when possible, use an EPA-registered repellent with DEET or picaridin, and keep air conditioning and window and door screens in good repair. Those steps reduce the places mosquitoes breed and the chances they land on people in the first place, which is the fastest way to blunt a West Nile season that has already begun early in Harris County.