/Health District reports first 2019 West Nile case

Health District reports first 2019 West Nile case

Encourages everyone to take precautions against mosquito bites

April 26, 2019

LAS VEGAS – The Southern Nevada Health District is reporting its first human case of West Nile virus in Southern Nevada in 2019. The individual, a female over the age of 50, had the more serious neuroinvasive form of the illness and has recovered. There were no reported human cases of West Nile virus in Clark County last year.

“West Nile virus is a preventable illness, and it is important to remind everyone to take steps to prevent mosquito bites, especially as we start to spend more time outside,” said Dr. Joe Iser, Chief Health Officer for the Southern Nevada Health District. “There are simple things you can do to prevent bites and to prevent mosquito breeding around your home to protect yourself, your family, and your community.”

West Nile virus is spread through the bites of infected mosquitoes that have acquired the virus by feeding on infected birds. The illness is not spread person to person. Many people with the virus will have no symptoms or very mild clinical symptoms of illness. Mild symptoms include fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach, and back. In some cases, the virus can cause severe neurologic illness and even death.

The Southern Nevada Health District’s Mosquito Surveillance Program regularly tests mosquito pools for West Nile, St. Louis Encephalitis, and Western Equine Encephalitis. To date, 174 traps were set throughout Clark County with 496 mosquitoes submitted to the Southern Nevada Public Health Laboratory for analysis. The Health District has not reported any mosquito pools that are positive for West Nile virus, St. Louis Encephalitis, or Western Equine Encephalitis so far this season. The program also conducts surveillance for Aedes aegypti and Aedes albopictus mosquitoes, the two species known to spread the Zika virus.

“It’s important to remember that mosquito-borne disease can be in our community even though our Mosquito Surveillance Program has not identified any West Nile virus-positive mosquito pools,” added Iser.

The Health District recommends the following to prevent mosquito bites and to eliminate breeding sources:

  • Use Environmental Protection Agency (EPA)-registered insect repellants containing DEET, Picaridin, IR3535, Oil of lemon eucalyptus (OLE), or 2-undecanone.
  • Wear pants and long-sleeved shirts to reduce mosquito exposure when outdoors.
  • Eliminate areas of standing water around your home, including non-circulating ponds, “green” swimming pools, and accumulated sprinkler runoff, which support mosquito breeding.

Additional prevention tips are available on the CDC’s Prevent Mosquito Bites webpage.


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.