Mosquitoes, West Nile virus activity looks increasingly bad this year in OC

Key Points:

• Orange County is on track to record the highest number of West Nile virus-carrying mosquitoes in its history this season, with 102 positive mosquito pools detected so far, compared to 186 at the end of 2025.
• West Nile virus, transmitted to humans through mosquito bites after mosquitoes bite infected birds, can cause mild flu-like symptoms in one in five infected people, while severe cases may lead to brain inflammation, hospitalization, or death.
• The virus has been found in mosquitoes across 16 Orange County cities, particularly in Anaheim, Buena Park, and Fullerton, though no human infections have been reported this year so far.
• The Orange County Mosquito Vector and Control District is actively combating the increase by treating standing water with mineral oil, releasing sterilized male mosquitoes to reduce populations, and urging residents to eliminate stagnant water around their homes.
• Residents are advised to take precautions such as removing standing water weekly, wearing protective clothing at dawn and dusk, using EPA-registered repellents, and reporting dead birds or high mosquito activity to local authorities for free mosquito control services.