West Nile Is Already Active in Southern Denton County — and the Trap That Came Back Positive Is Right by Keith Road

If you live anywhere between Flower Mound and Argyle, your mosquito window just got a lot smaller. Denton County Public Health announced that a trap south of Argyle tested positive for West Nile virus — and according to the county's surveillance map, it sits along Keith Road, near Liberty Christian School and Milestone Church. That's unincorporated Denton County, yes. But mosquitoes are not impressed by jurisdictional lines.

This is the third positive trap in Denton County for the 2026 season. The first southern Denton County trap to test positive this year was in Lewisville on May 19. We're not even in June. Most people think of West Nile as an August problem. It starts now.

Denton County Public Health will conduct ground fogging in the area three times — between 9 p.m. and 5 a.m. — running from Friday, May 29, through Thursday, June 4, weather permitting. If you're in that zone and you hear the truck, that's not a coincidence.

Here's the part worth sitting with. About 1 in 150 people infected with West Nile will develop a more severe form of the disease — encephalitis or meningitis, with symptoms like high fever, neck stiffness, tremors, and paralysis. People over 50 and those with weakened immune systems face the highest risk of serious illness. Most people who get infected feel nothing at all, or have a few days of flu-like aches. The unlucky fraction can end up hospitalized. There's no vaccine. No treatment for the virus itself. Prevention is the whole game.

The good news — and this is a genuinely Flower Mound-specific perk — the town is one of the few places in southern Denton County offering free mosquito dunks to residents. Pick up two per household at Town Hall on FM 1171; bring a utility bill or driver's license as proof of residency. The dunks go in standing water you can't drain — a bird bath, a planter saucer, a low spot in the yard that holds rain. They kill larvae before those larvae become biting adults.

While you're at it, walk your yard this week. Check bird baths, flowerpots, and clogged rain gutters — anywhere water sits. Drain anything you can. Stay inside at dusk and dawn, when mosquitoes feed. When you're outside, wear long sleeves or use an EPA-registered repellent with DEET, picaridin, or oil of lemon eucalyptus.

If you develop a fever, headache, or body aches in the next few weeks, tell your doctor about outdoor exposure. The county will keep updating its mosquito surveillance map at DentonCounty.gov/WNV as more traps come back. Expect more red markers as the season heats up. This is the early warning. Take it.