Mosquitoes carrying West Nile virus found in L.A. County

Los Angeles County has detected mosquitoes carrying the West Nile virus for the first time this year.

The mosquitoes were recovered from a trap in the Winnetka neighborhood of the San Fernando Valley, the Greater Los Angeles County Vector Control District said Saturday.

“While the presence of West Nile Virus in our community is not unusual, this early detection serves as a critical reminder for all residents to take preventative actions,” said Steve Vetrone, the director of scientific and technical services at the vector control district, in a prepared statement. “We urge everyone to protect themselves from mosquito bites and to eliminate standing water around their homes where mosquitoes can breed.”

The main spreader of the West Nile virus in California is the culex mosquito, which becomes infected with the virus by feeding on the blood of infected birds. The disease is usually spread to humans through mosquito bites.

About 20% of people infected with West Nile virus have symptoms, which can include fevers, headaches, body aches, nausea, skin rashes and fatigue. In rare cases, the infections can lead to serious brain and spinal cord inflammation. People who are 60 and older have a higher risk of complications.

There is no human vaccine for West Nile virus. Public health officials say the best way to protect yourself is to wear insect repellent and long sleeves and pants in mosquito-infested areas.

It also helps to eliminate standing water, where mosquitoes breed. Experts recommend emptying out any standing water in rain gutters, buckets, planters or any other area that can hold water for more than a week.

Neglected swimming pools with green water can also be reported to the local vector control district for treatment.

Experts have warned that California’s record-breaking rainfall could lead to a boom in the mosquito population and an increase in West Nile virus.

There were 461 cases of West Nile in humans in California last year, and 19 were fatal, according to the California Mosquito-Borne Virus Surveillance and Response Program.

The number of mosquitoes with West Nile virus in the Golden State rose about 78% between 2013 and 2023, the program said.

California has reported 25 samples of mosquitoes carrying the West Nile virus so far this year, up from five at the same time last year, according to the data. Of those 25, 18 were found in Riverside County.

The state has also reported 17 dead birds carrying the virus, up from 14 at the same time last year.