Woman hospitalized in region's first West Nile case of the year as officials issue mosquito warning

Health officials say the first human West Nile virus case reported in the region this year involved a Clark County resident in her 40s, as the Las Vegas Sun reported. It was a neuroinvasive infection, and she was hospitalized.

What happened?

According to a news release from the Southern Nevada Health District, the patient spent time in Clark County during the virus's incubation period and had also traveled to another state that has reported several human West Nile virus infections. The agency did not identify the state. 

Fortunately, the woman has since recovered from the ailment. Officials still do not know where the exposure happened. 

"Most people infected with West Nile virus experience mild symptoms or no symptoms at all, but some infections can result in serious illness," Dr. Cassius Lockett of the Southern Nevada Health District said in the release.

So far this year, mosquitoes collected through Clark County's surveillance program have not tested positive for West Nile virus, officials said. The health district began that program on March 9, earlier than usual because of warm temperatures, the Las Vegas Sun noted.

As of June 1, officials had deployed 920 mosquito traps around the county. They had also submitted 957 mosquito pools, representing more than 20,000 mosquitoes, for testing.

Why does it matter?

One serious case does not necessarily signal a broader outbreak, but mosquito-borne illnesses remain a seasonal risk, especially when both travel-related and local exposure are possible.

West Nile virus can be difficult to track because most infected people do not become seriously ill. The more severe neuroinvasive form can affect the brain, spinal cord or nervous system.

The early start to mosquito monitoring this year also reflects the range of species officials are tracking. Along with Culex mosquitoes, which are most commonly associated with West Nile virus, officials said they are also watching Aedes aegypti, first identified locally in 2017 and later found with West Nile in Clark County in 2024.

District data cited in the release show about 26 human West Nile virus cases in 2024, including 14 neuroinvasive cases and 12 nonneuroinvasive cases. In 2025, no human cases were reported.

What can I do?

The Health District suggested reducing mosquito exposure and eliminating places where mosquitoes can breed. That means using insect repellent, wearing protective clothing when possible, and avoiding bites, especially around dawn and dusk.

Around the home, standing water is the main thing to watch for. Containers, buckets, plant saucers, and anything else that can collect water can become breeding spots, so emptying them regularly can help lower the risk.

The health district is continuing its surveillance work to spot problems early and warn the public if mosquito testing begins to show local spread.

Exposure does not always happen where symptoms are first noticed. Precautions at home and while traveling both matter during mosquito season.

"Taking simple precautions to avoid mosquito bites and eliminate mosquito breeding areas around your home or while traveling can significantly reduce your risk." Lockett declared in the release.

Get TCD's free newsletters for easy tips, smart advice, and a chance to earn $5,000 toward home upgrades. To see more stories like this one, change your Google preferences here.