Mosquito traps in Flower Mound and Lewisville have tested positive for West Nile Virus this summer, with two new positive samples recorded in Lewisville on Tuesday, July 28, bringing that city's total to four for the year.
The trap results, reported Friday by the Cross Timbers Gazette citing Denton County Public Health surveillance data, place confirmed virus activity squarely within the Flower Mound and Lewisville area during peak mosquito season. Additional positive traps have been found near Argyle and in the Harvest community.
Flower Mound had already recorded at least two positive traps within town limits by early July.
The trap data comes as Denton County Public Health on Thursday, July 30, confirmed the county's second human West Nile case of 2026. A resident of The Colony was diagnosed with West Nile Virus Neuroinvasive Disease, the severe form of the illness that can cause encephalitis, meningitis, or paralysis. The county's first human case, a Denton resident, was diagnosed in early July.
The virus is spreading fast.
As we reported July 30, the neuroinvasive form strikes roughly 1 in 150 infected people, according to the World Health Organization, with adults over 50 and immunocompromised individuals at highest risk.
"We encourage all community members to practice prevention to reduce their risk," Juan Rodriguez, DCPH's assistant director and chief epidemiologist, said in the July 30 announcement. Rodriguez noted there are no vaccines or medicines to prevent West Nile Virus in people.
DCPH is urging residents to take three steps:
- Drain standing water from bird baths, flowerpots, and clogged rain gutters. Use BTI briquettes (mosquito dunks) in water that cannot be eliminated.
- Dress in long sleeves and pants when outdoors, and spray thin clothing with repellent.
- Defend with EPA-registered repellent containing DEET, Picaridin, or Oil of Lemon Eucalyptus.
The county conducted overnight fogging east of Oak Point from Thursday, July 23, through Wednesday, July 29. No spraying schedule for Flower Mound or Lewisville has been announced.
Residents can find mosquito surveillance maps and the latest updates at DentonCounty.gov/WNV.
