Health District identifies first West Nile virus-positive mosquitoes of the season
Public urged to “Fight the Bite”
FOR IMMEDIATE RELEASE:
July 29, 2025
LAS VEGAS – The Southern Nevada Health District has identified the first mosquito pool of the season testing positive for West Nile virus in the 89123 ZIP code. The Health District is reminding residents to take precautions and “Fight the Bite” to help reduce the impact of mosquitoes in the community.
Since launching its seasonal mosquito surveillance in April, the Health District has set more than 1,670 traps across Clark County to monitor mosquito species and detect virus activity. Traps are placed in parks, wash channels, wetlands, residential areas and other potential breeding sites. Collected mosquitoes are sorted and cataloged by species and location at the Health District’s Main Public Health Center, and samples are then sent to the Southern Nevada Public Health Laboratory for testing. More than 1,800 mosquito pools have been tested this year.
West Nile virus activity in Clark County reached unprecedented levels in Clark County in 2019, with 43 reported human cases. Activity was minimal in 2021, 2022 and 2023. In 2024, 26 human cases were reported.
In addition to identifying mosquitoes that commonly carry West Nile virus, the Health District is monitoring the presence of Aedes aegypti mosquitoes, which can transmit Zika, dengue and chikungunya. Unlike most mosquitoes, Aedes aegypti are aggressive daytime biters that prefer humans to birds. They are persistent ankle-biters, and a single female can bite multiple times. These mosquitoes breed in small containers that collect rain or irrigation water—such as children’s toys, wheelbarrows, plant saucers and even bottle caps.
The Health District’s Fight the Bite campaign encourages people to:
- Eliminate standing water around their homes.
- Use an FDA-registered insect repellent and wear protective clothes.
- Report mosquito activity to the Health District’s surveillance program at (702) 759-1633.
- Report green pools to local code enforcement agencies.
Additional resources and contact information are available on the Health District website. For more information about mosquito surveillance, visit www.snhd.info/mosquito.
The Southern Nevada Health District serves as the local public health authority for Clark County, Boulder City, Henderson, Las Vegas, Mesquite and North Las Vegas. The agency safeguards the public health of the community’s residents and visitors through innovative programs, regulations, and initiatives focused on protecting and promoting their health and well-being. More information about the Health District, its programs, services, and the regulatory oversight it provides is available at www.SNHD.info. Follow the Health District on Facebook, Twitter, and Instagram.