/West Nile Virus Update

West Nile Virus Update

Health District reports sixth case of West Nile virus

July 26, 2019

LAS VEGAS – The Southern Nevada Health District is reporting Clark County’s sixth case of West Nile virus. The individual is a female under the age of 50 who has the neuroinvasive form of the illness. West Nile virus is considered endemic in Clark County, having first been identified in 2005. This new case is a reminder to the public of the importance of preventing mosquito bites and eliminating breeding sources around their homes. The Health District is also alerting the community to the ongoing outbreak in the mosquito population. The West Nile and St. Louis encephalitis viruses are being actively transmitted from infected birds to mosquitoes, which then places the public at increased risk for disease.

West Nile virus-positive mosquitoes have been found in 25 unique ZIP codes and mosquitoes testing positive for the St. Louis encephalitis virus have been found in 10 unique ZIP codes so far this season. More than 33,000 mosquitoes have been submitted for testing this year. Of those samples, 4,987 pooled samples have tested positive for West Nile virus, and 433 have tested positive for St. Louis encephalitis.

To prevent mosquito bites the public should use Environmental Protection Agency (EPA)-registered insect repellants containing DEET, Picaridin, IR3535, Oil of lemon eucalyptus (OLE), or 2-undecanone. Eliminate areas of standing water, including non-circulating ponds, “green” swimming pools, and accumulated sprinkler runoff, which support mosquito breeding. For more tips, go to the Health District’s Mosquito Breeding Prevention website. For additional information and weekly updates on the Health District’s mosquito surveillance activities go to: www.southernnevadahealthdistrict.org/programs/mosquito-surveillance/weekly-arbovirus-update/.


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.