In 2026 to date, the Los Angeles County Department of Public Health (LA County DPH) has documented 135 West Nile virus (WNV) human infections and five deaths.
In all of 2025, 22 cases and two deaths were reported in the county. The number of persons infected in the 2026 season is greater than the 5-year average during the same period of time.
Of the 135 cases, 120 were neuroinvasive disease, 10 West Nile fever and 5 were asymptomatic blood or organ donors.
130 cases required hospitalization for their illness.
Of the neuroinvasive cases, 91 were encephalitis, 20 were meningitis and 9 were acute flaccid paralysis.
According to the CDC, 987 total WNV cases were reported in 43 states, including 750 neuroinvasive cases. California has reported the most with 211.