DSHS confirms first West Nile case in Texas in 2026

Urges vigilance against all mosquito-borne illnesses, including dengue

The Texas Department of State Health Services is reporting this year's first case of West Nile illness in a resident of Harris County. Health officials confirmed the resident was diagnosed with West Nile virus neuroinvasive disease.

"West Nile and other mosquito-borne illnesses are a fact of life in Texas in the warmer months, and all Texans should take precautions against mosquito bites to stay safe and healthy," said DSHS Commissioner Jennifer A. Shuford, MD, MPH. "By removing standing water around the home, people can eliminate mosquito breeding grounds and reduce insect populations in their area."

West Nile virus is transmitted through the bite of infected mosquitoes, but roughly 80% of people infected with West Nile never experience symptoms. Roughly 20% will develop West Nile fever, experiencing symptoms like fever, headache, nausea, muscle and joint aches, and fatigue. Less than 1% will contract West Nile neuroinvasive disease, a more serious neurological illness that causes tremors, convulsions, neck stiffness, disorientation, paralysis, and even death.

There have been 976 total West Nile cases (West Nile fever and West Nile neuroinvasive) reported in Texas during the last five years. During that span, there were 106 deaths in the state attributed to West Nile. During that period, 2024 had the most recorded deaths at 57, while 2025 fatalities were the fewest at 9. (Data for 2024 and 2025 are provisional and subject to change.)

Preventing West Nile illness begins by eliminating the breeding grounds of mosquitoes. Water should be removed from items like flowerpots, buckets, kiddie pools, dog bowls, toys, and clogged rain gutters, which can offer mosquitoes a place to lay eggs and reproduce. Texans should also strive to keep mosquitoes from entering a home by using air conditioning and making sure window and door screens are in good repair.

Texans should wear long-sleeved, loose-fitting shirts and pants, and socks and during the times of the day when mosquitoes are most active. Mosquito repellents with DEET or picaridin are also effective at preventing bites. These precautions will also protect against other mosquito-borne viruses, like dengue, chikungunya and Zika.

Dengue and chikungunya cases have been on the rise globally in recent years. These viruses are endemic in many countries, including the Caribbean, Central and South America, Africa, Asia, and the South Pacific. While most Texas dengue and chikungunya cases are travel associated, there have been a few locally acquired cases in southern Texas in recent years. About 25% of those infected with dengue will experience symptoms like fatigue, nausea, vomiting, rash, joint and bone pain, and headache. Most will recover within two weeks but one in 20 symptomatic people will develop a severe disease that can be fatal if untreated. For those infected with chikungunya, most people will have symptoms that are often similar to dengue.

While there is no vaccine against West Nile virus, a chikungunya vaccine is available for travelers to endemic regions. Ask your health care provider for more details, especially before travelling internationally, and always take mosquito bite prevention steps when traveling to tropical and sub-tropical areas.

Those same prevention measures should continue when you return to Texas. If you become infected with dengue or chikungunya on your trip, it's possible that local mosquitoes can bite when you return home and then spread either the dengue or chikungunya virus to others in Texas.

You can learn more at the DSHS mosquito-borne diseases site.

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