The resident was hospitalized after developing West Nile virus encephalitis following the onset of symptoms in late June, according to the Los Angeles County Department of Public Health.
"The first human cases of West Nile virus are an important reminder that we all need to take steps to prevent mosquito bites and mosquito
breeding,'' Los Angeles County Health Officer Dr. Muntu Davis said in a statement. "Mosquitoes thrive in hot weather, increasing the risk of bites and mosquito-borne diseases.''
Davis urged residents to use insect repellent, eliminate standing water around homes where mosquitoes can breed and ensure window and door screens are properly installed and maintained.
Officials also encouraged residents to report neglected swimming pools that could serve as mosquito breeding grounds and to notify authorities when dead birds are found, since increases in infected birds often precede human cases of the virus.
Public health officials said West Nile virus is spread through the bite of an infected mosquito and can cause symptoms including fever, headache, nausea, body aches and skin rash. In severe cases, the virus can affect the nervous system and lead to meningitis, encephalitis, paralysis or death.
Adults older than 50 and people with chronic health conditions face a higher risk of severe illness, according to health officials.
"Detecting West Nile virus in our district is a reminder that this virus has been present in California -- and right here in our community -- for
over 20 years,'' Brenna Bates-Grubb of the Antelope Valley Mosquito and Vector Control District said. It's part of our local environment and continues to reappear year after year.''
Public health officials report human cases of West Nile virus every year in Los Angeles County, averaging 41 annually over the last five years, excluding cases reported separately by the Pasadena and Long Beach health departments.
Health officials said there is no vaccine or specific treatment for West Nile virus.
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