LA County confirms season's first human West Nile virus case

File: Aedes aegypti mosquito photographed through a microscope.
File: Aedes aegypti mosquito photographed through a microscope.
Felipe Dana/AP

An elderly resident of the San Gabriel Valley was hospitalized in late March in the first case of human West Nile virus infection in L.A. County for the 2017 season, health officials confirmed Thursday.

The resident has since recovered, but the L.A. County Department of Public Health urged residents, especially those older than 50, to take precautions against mosquito bites, including by using a repellent containing DEET when outdoors.

“West Nile is a serious illness spread by mosquitoes in Los Angeles County,” Jeffrey Gunzenhauser, the county's interim health officer, said in a statement.

A vaccine for West Nile virus doesn't exist, and symptoms from the illness can last up to a year, Gunzenhauser added.

Mosquitoes are mostly active form dusk to dawn. "That's the time when we say it's most at-risk for humans," the health department's Dr. Dawn Tershita told KPCC.

The department recommends wearing long sleeves and pants to avoid mosquito bites when outside. Symptoms of West Nile virus can include fever, headache, and aches and pains.