Early detection of West Nile Virus mosquitoes in Southern Nevada

Public urged to “Fight the Bite” and help curb mosquitoes’ impact

FOR IMMEDIATE RELEASE:
May 24, 2024

LAS VEGAS – As the 2024 mosquito surveillance season begins, the Southern Nevada Health District announces the detection of the first West Nile Virus (WNV) positive mosquitoes in Clark County. With these early findings, the Health District urges Clark County residents to join the Fight the Bite campaign to reduce the impact of mosquitoes.

The Health District’s Mosquito Disease Surveillance Program trapped and identified the West Nile virus-positive mosquitoes in the 89031 and 89032 ZIP codes. In addition to identifying mosquitoes that commonly carry West Nile Virus, Aedes aegypti mosquitoes are known carriers of Zika, dengue, and chikungunya. Aedes aegypti mosquitoes have significantly increased in number since they were reported in Clark County in 2017.

Since starting its seasonal mosquito surveillance on April 1, Health District staff have set more than 875 traps to survey mosquito quantity, species and infected mosquitoes. Traps are placed at parks, wash channels, wetland areas, residential communities and other potential breeding sites. Captured mosquitoes are taken to a laboratory at the Health District’s Main Public Health Center, where they are sorted and cataloged by species and location. The samples are then sent to the Southern Nevada Public Health Laboratory to test specimens for harmful arboviruses. To date, more than 9,000 mosquitoes have been tested this year.

West Nile Virus, a mosquito-borne disease, reached unprecedented activity in Clark County in 2019, with 43 human cases. In contrast, there was minimal activity in 2020, 2021 and 2022. Two human cases of West Nile Virus were reported in 2023.

Clark County has seen a substantial increase in the number of Aedes aegypti mosquitoes. Unlike typical mosquitoes, Aedes aegypti are aggressive daytime biters that prefer feeding on people instead of birds. They are persistent ankle-biters, with a single female capable of taking many bites.

Aedes aegypti breed in small containers that collect rain or irrigation water, such as children’s toys, wheelbarrows and plant saucers, and even bottle caps. Since the initial identification of Aedes aegypti in 2017 in four Clark County ZIP codes, their presence expanded to 12 ZIP codes in 2022 and 43 in 2023.

The Fight the Bite campaign calls on people to eliminate standing water; prevent mosquito bites by taking proper precautions; and report mosquito activity to the Health District’s surveillance program at (702) 759-1633. To report a green pool, people should contact their local code enforcement agency. 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.