Nevada swarming with over 3,000 mosquitos infected with West Nile Virus: "It is explosive here"

If you're planning a trip to Las Vegas, bring lots of insect repellent — 3,081 mosquitoes from 91 pools and 16 zip codes in Nevada have tested positive for West Nile Virus, according to a Southern Nevada Health District press release. And this includes Las Vegas.

In two of the zip codes, 46 mosquitos also tested positive "for the virus that causes St. Louis encephalitis," which, although not common, could cause encephalitis or meningitis if a person is bitten by one of these infected mosquitos.

West Nile Virus isn't anything new, but "now it is explosive here," says Louissa Messenger, an assistant professor in the Department of Environmental & Occupational Health at the University of Nevada, Las Vegas (see her short interview in video below, posted by KTNV's Joe Moeller).

While most people who are infected with West Nile Virus have little or no symptoms, about one in five people will experience flu-like symptoms such as fever, body aches, headaches, and nausea. And about one in 150 will come down with a "more serious, sometimes fatal, illness."

From the SNHD press release:

As of June 6, 2024, 91 mosquito pools, comprising 3,081 mosquitoes from 16 ZIP codes, have tested positive for West Nile virus. Two mosquito pools, comprising 46 mosquitoes from two ZIP codes, have tested positive for the virus that causes St. Louis encephalitis.

The Health District's Mosquito Surveillance Program has also received an increased number of complaints from the public about mosquito activity. Increased awareness and reporting of mosquito activity are attributed to the expansion of Aedes aegypti mosquitoes throughout the region. Aedes aegypti mosquitoes are known to be aggressive daytime biters that prefer feeding on people instead of birds and have tested positive for West Nile Virus for the first time in Clark County.

Most people infected with the virus will not develop symptoms. People who become ill may develop fever, headache, nausea, vomiting and fatigue. Some people may develop a neuroinvasive form of the disease that causes encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes surrounding the brain and spinal cord).

West Nile virus is spread to people through the bite of an infected mosquito. About one in five people infected with West Nile virus will develop symptoms that can include fever, headache, body aches, vomiting, diarrhea or rash. About one in 150 will develop more serious, sometimes fatal, illness. People who think they might have West Nile should talk with their health care provider. …

More Fight the Bite tips and resources are available at and on the Centers for Disease Control and Prevention website at

The Health District's seasonal mosquito surveillance reports are available at

Previously: West Nile mosquitoes spike in Colorado, killing 48 people