By Natalie Frels
•
July 30, 2025
SAN MARCOS, Texas – The Hays County Health Department (HCHD) received notification on July 29, 2025, that there was a laboratory confirmed, positive human case of West Nile Virus. This is the first reported human case of West Nile Virus (WNV) for the 2025 Mosquito Season in Hays County. Due to privacy and confidentiality reasons, HCHD will not disclose any information about the patient. While 80% of people will not experience symptoms of an infection, only 20% of people may experience some symptoms. Symptoms of West Nile Virus infection can include fever, headache, body aches, joint pain, vomiting, diarrhea, a skin rash on the torso of the body and swollen lymph nodes. While the risk for severe symptoms is low, individuals aged 50 and older and those with compromised immune systems may be at an increased risk for stiffness, disorientation, coma, tremors, vision loss, paralysis and, in extremely rare cases, death. Anyone experiencing these symptoms is encouraged to seek medical attention. Currently, there is no specific treatment for West Nile Virus, but over the counter medicine can help reduce symptoms and supportive care can be provided in a hospital setting to those experiencing more severe symptoms. Patients can expect to exhibit symptoms for three to six days but may experience fatigue and weakness for weeks or even months. WNV is a disease that is spread by the bite of an infected mosquito. Mosquitoes can become infected when they feed on the blood of infected birds. The infected mosquitoes can then transmit WNV to humans and animals. Severe WNV infections can cause neurological complications such as encephalitis and/or meningitis. Hays County Epidemiologist Ian Harris wants to remind residents that “West Nile Virus is not contagious and that humans are ‘dead-end host,’ meaning humans are not capable of transmitting the virus to other individuals.” The Department of State Health Services (DSHS) has not confirmed a positive mosquito pool in Hays County during the 2025 Mosquito Season. The county reported positive mosquito pools for WNV in Hays County during the 2024 Mosquito Season. In the state of Texas, DSHS reported 3,314 positive mosquito pools in 2024 for West Nile Virus. As of July 29, 2025, DSHS has reported 272 positive mosquito pools for West Nile Virus. The key to preventing West Nile Virus is to minimize the number of mosquitoes in areas where people live, work and play. Public health officials strongly encourage everyone to remain vigilant about protecting themselves from mosquito bites and preventing mosquito breeding on their properties. 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. HCHD reminds residents to remember the 3 Ds: DEET, Dress and Drain. DEET: Whenever outside, use insect repellents with the active ingredient DEET or other EPA-registered 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. Hays County Development Services is providing mosquito surveillance within the county to monitor and track mosquito-borne illnesses. Some mosquitoes can transfer potentially deadly diseases – known as arboviral diseases – to humans. HCDS is collecting mosquitoes to determine which areas are harboring disease-carrying mosquitoes. HCDS will set up collection traps across the county on a rotating basis to capture samples of several species of mosquitoes that will be sent to the Department of State Health Services in Austin for identification and determination of the type(s) of illness the mosquitoes could be spreading. Monitoring species, mosquito density and geographic breeding sites will provide critical early predictive data to HCDS to help monitor, prevent and combat mosquito populations and mosquito-borne illnesses. HCDS uses the Centers for Disease Control and Prevention (CDC) gravid-trapping method to collect mosquitoes. This trap is designed to attract female mosquitoes which are ready to lay eggs. The trap uses a fan to draw in mosquitoes that approach the liquid in the bottom of the bucket and keeps them in a collection bag until the trap is collected. HCDS also uses the BG-Sentinel trap. This trap targets other mosquito species that are vectors of other arboviruses. Collection is typically carried out from May until November throughout Texas. Hays County Development Services and the Hays County Health Department will continue to conduct mosquito pool traps and health surveillance to promote the health and safety of our residents. For more information regarding mosquito abatement, contact Hays County Development Services at 512-393-2150. Resident can view Mosquito Tracking Locations via the Hays County Development Services GIS Dashboard at https://bit.ly/HaysCountyMosquitoTrackingLocations. Visit the Texas Department of State and Health Services West Nile website for more information on the disease at txwestnile.org. # # #