Orange County ramps up mosquito control as West Nile cases surge

West Nile virus has been identified in mosquito samples from 13 Orange County cities this season, with the number of positive samples more than doubling in a single week, according to the Orange County Mosquito and Vector Control District. The district has recorded 38 positive samples, and Fullerton accounts for roughly 40% of those cases, reporting 15 positive samples.

In response, officials have begun overnight mosquito-control treatments in a 4.5-square-mile section of Fullerton, scheduled from Thursday through Saturday. Crews will spray between about 1 a.m. and 5 a.m. each night in an area bounded by Valencia Drive, the 91 Freeway, Euclid Street and Raymond Avenue. > "We only treat when there is an abundance of mosquitoes and the presence of disease," district officials told KTLA. "Then that triggers us to go out with our trucks and knock down the adults."

Residents in the spray zone have been notified and are being urged to eliminate standing water, clean bird baths and pet bowls, repair torn screens, and use insect repellent containing DEET, picaridin, IR3535 or oil of lemon eucalyptus. The district also encourages reporting of neglected pools or unusually heavy mosquito activity for inspection.

West Nile virus spreads through the bite of an infected mosquito. While most infected individuals remain asymptomatic, some may develop fever, headache, body aches, vomiting, diarrhea or a rash. In rare cases, the infection can lead to severe neurological illness such as encephalitis or meningitis, with older adults and immunocompromised persons at higher risk.