West Nile virus in Hays County: Fourth mosquito trap tests positive

SAN MARCOS, Texas - A fourth mosquito trap has tested positive for West Nile virus in Hays County.

The backstory:

The mosquito trap sample was collected from a site in San Marcos on July 28. 

This is the fourth West Nile virus-positive mosquito pool reported in Hays County in 2026.

At this time, no human cases have been reported in the county.

For more information, visit Hays County Development Services website or call
(512) 393-2150

What they're saying:

"A few days ago, HCDS received confirmation from DSHS that the positive sample originated from San Marcos," said Nick VandenBroek, Environmental Health Specialist II. "We are continuing to actively monitor locations across the county and respond promptly by notifying the citizens of Hays County."

"The detection of another mosquito trap testing positive for West Nile virus underscores the importance of continued vigilance. Hays County is working closely with our local and state public health partners to monitor mosquito activity, conduct appropriate surveillance and mitigation efforts, and keep residents informed," said Hays County Judge and Director of Emergency Management Ruben Becerra. "We encourage everyone to take simple preventive measures, including eliminating standing water around their homes, using EPA-approved insect repellent, and limiting outdoor exposure during peak mosquito activity. By working together, we can help reduce the risk of mosquito-borne illness and protect the health of our community."

What is West Nile virus?

Dig deeper:

While mosquitoes are present year-round, they are most active from May through November.

Infected mosquitoes can transmit West Nile through bites.

Symptoms

Symptoms of the infection can include fever, headaches, body aches, joint pain, vomiting, diarrhea, a skin rash on the torso of the body, and swollen lymph nodes.

About 80% of infected people usually show no symptoms.

While the risk is low for severe symptoms, people over the age of 50 and those with compromised immune systems can be at an increased risk for stiffness, disorientation, coma, tremors, vision loss, paralysis and, in extremely rare cases, death.

Patients can expect to have symptoms for three to six days, but may experience fatigue and weakness for weeks or even months.

There is currently no treatment for West Nile virus.

Preventing mosquito breeding

Everyone is encouraged to protect themselves from mosquito bites and prevent mosquito breeding.

Mosquitoes can breed in as little as one teaspoon of standing water. By draining all sources of standing water in and around your property, you reduce the number of places mosquitoes can lay their eggs and breed.

Remember the 3 Ds:

• Defend: Whenever outside, use EPA-approved insect repellents, and always follow label instructions.
• Dress: Wear long, loose and light-colored clothing outside.
• Drain: Drain or treat all standing water in and around your home or workplace where mosquitoes could lay eggs.

San MarcosHealth