In a concerning turn of events, the Southern Nevada Health District (SNHD) has announced a significant surge in mosquito activity this early in the year, setting a new record. Alongside this unsettling development, an increasing number of public complaints have been received by the district.

As of June 6, the SNHD's Mosquito Surveillance Program disclosed that a total of 91 mosquito pools, encompassing 3,081 mosquitoes from 16 zip codes, have tested positive for the West Nile Virus. Furthermore, two mosquito pools, consisting of 46 mosquitoes from two zip codes, have been found to carry the virus responsible for St. Louis encephalitis.

This rise in mosquito numbers has been attributed to the spreading presence of the Aedes aegypti mosquito within the region. Notably, these mosquitoes are known to be aggressive daytime biters that have shown a preference for feeding on humans rather than birds. This has led to the first-ever positive tests for West Nile Virus in Clark County.

According to the SNHD, the last known instance of mosquitoes testing positive for St. Louis encephalitis in Clark County occurred in 2019, with no reported human cases since 2016. It is worth noting that while most individuals bitten by an infected mosquito may not experience any symptoms, about one in five people may fall ill, encountering fever, headache, rash, nausea, vomiting, diarrhea, and fatigue. Additionally, a small fraction (approximately one in 150 people) may develop a more severe neuroinvasive form of the disease, resulting in encephalitis or meningitis.

Reflecting on previous years, the health district has highlighted minimal West Nile virus activity throughout 2020, 2021, and 2023. However, 2019 saw a staggering 43 human cases reported. To stay informed, the public is encouraged to refer to the mosquito surveillance reports and the accompanying map, which highlight the areas of heightened mosquito activity in the valley.

Mitigating mosquito activity this summer is crucial to prevent the further spread of West Nile Virus and St. Louis encephalitis in Clark County. The SNHD will undoubtedly ramp up its efforts to address this issue, ensuring public safety remains a top priority.

It is advisable for individuals to take necessary precautions, such as using mosquito repellents, wearing protective clothing, and eliminating stagnant water sources, to minimize the risk of mosquito bites and potential transmission of these viruses.