Santa Clara County, the most populous region in the Bay Area, has reported its first mosquito-related death of the year. Health officials confirmed two human cases of West Nile virus, with one adult recovering at home after hospitalization and another immunocompromised adult passing away earlier this month.

This marks the first West Nile virus death in the county in nearly two decades. The health department noted that there was no known connection between the two cases, and neither individual was identified due to privacy concerns.

West Nile virus is primarily spread through the bite of an infected mosquito, which becomes a carrier after feeding on infected birds. Last month, Santa Clara County officials detected virus-carrying mosquitoes in five ZIP codes in northern San Jose and the Alum Rock area. In response, Vector Control sprayed pesticides to reduce the mosquito population.

Although it's unclear if the individuals contracted the virus within the county, state officials have warned of an intense mosquito season due to climate change and flooding, which creates stagnant water ideal for mosquito breeding. In 2023, California saw 473 West Nile virus cases and 20 deaths, more than double the previous year.

Residents are urged to drain standing water, use insect repellent, and seal windows and doors to protect against mosquito bites.

Contra Costa County also reported its first West Nile virus death since 2006, with an East County resident succumbing to the virus on July 16.