Yolo County reports its first West Nile virus death of 2026

Yolo County has reported its first death from West Nile virus this year as health officials say mosquito activity increases across the county and throughout California.

The resident who died had neuroinvasive West Nile virus, the most severe form of the disease, a spokesperson for Yolo County Public Health announced on Tuesday.

Officials also confirmed two additional cases of neuroinvasive West Nile virus among Yolo County residents this year. The county recorded just one such case in 2025.

It was not clear where in the county the person lived or may have been exposed.

Yolo County Health Officer Dr. Joanna Locke said older adults, people with weakened immune systems and those with certain underlying medical conditions are at greater risk of developing severe illness from the virus. Most people infected with the virus experience either no symptoms or mild illness.

Symptoms may include fever, headache, body aches, nausea or vomiting, according to public health officials. Rarer symptoms may include severe neurological illness, which officials said can require hospitalization and can be fatal.

"West Nile virus activity remains elevated throughout our region, and we are entering the time of year when mosquito populations and virus activity typically remain high," said Gary Goodman, district manager of the Sacramento-Yolo Mosquito & Vector Control District.

Officials are urging residents to take steps to reduce their risk, including eliminating standing water around their homes and using insect repellent when outdoors.

The county and mosquito district recommend limiting outdoor activity around dawn and dusk, when mosquitoes are most active, and ensuring doors and window screens are in good condition to keep mosquitoes outside.