Los Angeles County has confirmed the first four human cases of West Nile Virus (WNV) for the 2025 season.

The patients, hospitalized between July and August in Antelope Valley, San Fernando Valley, and central Los Angeles, are currently recovering.

The virus is transmitted through the bite of infected mosquitoes and can cause fever, headache, nausea, and in severe cases, meningitis, encephalitis, or paralysis. Adults over 50 and people with chronic health conditions are at higher risk of complications.

Authorities recommend using EPA-approved insect repellent, wearing protective clothing, keeping window and door screens in good condition, and eliminating standing water where mosquitoes breed. There is no specific treatment or vaccine for WNV.

Prevention and community cooperation are key to reducing mosquito exposure during the warm months when mosquito activity increases and the risk of infection rises.