Las Vegas is known for its lively attractions, but this summer, something far less desirable is drawing attention—record mosquito activity. Southern Nevada health officials report an alarming surge in mosquitoes testing positive for West Nile virus, making it the region’s highest level of mosquito activity on record.

According to the Southern Nevada Health District, as of June 6, 91 mosquito pools, containing over 3,000 mosquitoes from 16 ZIP codes, have tested positive for West Nile virus. Additionally, two mosquito pools tested positive for St. Louis encephalitis virus, marking the first detection of this virus in the area since 2019.

The spike in mosquito activity has led to an influx of complaints from residents, with health officials identifying the aggressive Aedes aegypti mosquito as a major culprit. These mosquitoes, known for biting during the day and preferring humans over birds, have tested positive for West Nile virus for the first time in Clark County.

While West Nile virus activity in Southern Nevada has been relatively low in recent years—only two human cases were reported in 2023—this resurgence is a stark reminder of the virus’s risks. In 2019, 43 human cases were confirmed in the region.

Understanding the Risks

West Nile virus is transmitted to humans through the bite of an infected mosquito. Most people who contract the virus experience no symptoms, but about one in five will develop fever, headaches, body aches, rashes, or other flu-like symptoms. In severe cases—around one in 150 infections—the virus can lead to life-threatening complications, such as encephalitis (brain inflammation) or meningitis (inflammation of the brain and spinal cord membranes).

St. Louis encephalitis virus, also transmitted through mosquito bites, presents similar risks. While most people remain asymptomatic, some may experience fever, nausea, and fatigue. Severe cases can result in neuroinvasive conditions, such as encephalitis or meningitis.

Taking Preventive Measures

Health officials are urging residents and visitors to take proactive steps to minimize the risk of mosquito-borne illnesses. Recommended measures include:

• Eliminating Standing Water: Mosquitoes breed in stagnant water, so it’s essential to regularly check and remove water from items like plant saucers, gutters, and pet bowls.
• Using Insect Repellent: Apply EPA-approved repellents containing DEET, picaridin, or oil of lemon eucalyptus when spending time outdoors.
• Wearing Protective Clothing: Long sleeves and pants can help reduce the likelihood of bites.
• Installing Screens: Keep doors and windows screened to prevent mosquitoes from entering homes.

While Las Vegas remains a prime destination for summer fun, travelers should remain vigilant and take these precautions to protect themselves from mosquito-borne illnesses.