Some people may want to put their summer vacation plans to the Las Vegas area on hold, after health officials reported that Southern Nevada is experiencing the highest level of mosquito activity in known history, with more than 3,000 mosquitoes testing positive for West Nile virus.
Southern Nevada Health District said in a press release Monday that as of June 6, 91 pools, comprising 3,081 mosquitoes from 16 ZIP codes, have tested positive for the virus. Two pools, comprising 46 mosquitoes from two ZIP codes, have also tested positive for the virus that causes St. Louis encephalitis.
The health district’s Mosquito Surveillance Program has received an increased number of complaints from residents about mosquito activity, according to the press release. Health officials attributed the rise in reports partly to the increased presence of Aedes aegypti mosquitoes in the area—these mosquitoes are aggressive biters during the day and tend to bite people rather than birds. Aedes aegypti have tested positive for West Nile virus for the first time in Clark County, the press release said.
For the past four years, Southern Nevada has had minimal West Nile virus activity, health officials said. Only two human cases of the virus were reported in 2023. In 2019, officials reported 43 confirmed human cases.