West Nile virus claims first 2026 death in California as Arizona reports surge in cases

Maricopa County, Arizona, is experiencing an active West Nile virus season with 47 confirmed human cases and five deaths. Health officials have tested 183 mosquito trap samples, all positive for the virus, indicating a high level of mosquito infection.

In Kings County, California, the first West Nile virus death of 2026 was reported after a resident succumbed to the illness. The county has recorded three human cases this year, including the fatal infection. Officials warned that while many infections are mild or asymptomatic, severe disease can affect older adults and those with underlying conditions, leading to neurological complications. No vaccine exists, so prevention focuses on eliminating standing water and avoiding mosquito bites.