Large numbers of mosquitoes testing positive for West NIle Virus

Las Vegas, NV (KXNT) – The Southern Nevada Health District says they’re encountering more zip codes with mosquitoes that have tested positive for West Nile Virus.

SNHD reported Monday that 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 (89014, 89015), have tested positive for the virus that causes St. Louis encephalitis.

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.

Only two human cases of West Nile were reported in Clark County last year. Since statistics have been kept, the all-time record for number of human cases was 43 back in 2019.

Mosquitoes testing positive for St. Louis encephalitis virus were last reported in Clark County in 2019 and the last reported cases in humans in 2016. 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).

The Health District’s seasonal mosquito surveillance reports are available at www.southernnevadahealthdistrict.org/programs/mosquito-surveillance/arbovirus-update/