Capital region’s first West Nile virus sample of 2026 found in Sacramento neighborhood
A mosquito sample collected in Sacramento County has tested positive for West Nile virus, according to the Sacramento-Yolo Mosquito and Vector Control District, the first detection of the virus in the capital region this year and the third in Northern California.
The sample, collected in an area south of Tahoe Park, is the first mosquito sample to test positive for the virus in Sacramento County this season. Mosquito season typically runs from May through October. No West Nile virus activity has been detected in Yolo County, district spokesperson Luz Maria Robles said.
“This finding is an important reminder that mosquito season is already underway, and much earlier than we typically see,” Gary Goodman, manager of the district, said in a statement. “It’s important for residents to take these findings seriously and do everything they can to protect themselves.”
West Nile virus was first detected in California in 2003 and is now considered endemic in Sacramento and Yolo counties. It is the most common mosquito-borne disease in the United States, according to the district.
There were 124 confirmed human cases of West Nile Virus in California last year, including 11 fatalities.
Robles said the district will increase mosquito trapping and surveillance to identify breeding sites. The district also may conduct targeted ground spraying to reduce adult mosquito populations.
As summer approaches, Goodman urged residents to wear insect repellent and report mosquito problems, dead birds — which can carry the virus — and neglected swimming pools, where mosquitoes breed in standing water. Residents also can report standing water, request free home inspections and receive mosquitofish for ponds and fountains through the district.
Robles said Fresno, Alameda, Santa Clara, Los Angeles and San Diego counties also have reported West Nile virus activity, signaling the start of mosquito season.
