By admin 
Placer County on Wednesday reported its first human West Nile virus case this season as statewide cases “soar,” reaching more than four times the number of cases this time last year, according to the Placer Mosquito and Vector Control District.
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This is the first human case in the county in 2026, though the mosquito-borne disease itself was first detected in June, the control district said in a news release. A total of nine dead birds and 112 mosquito samples collected in the county have tested positive for the virus, which is the most common and serious vector-borne disease in California.
Roughly 5% of people infected develop symptoms including fever, headaches, body aches, nausea and vomiting. More severe neurological symptoms, which affect fewer people, can lead to hospitalization and death.
The Placer County resident may have contracted the virus in another county, the release said.
“West Nile virus continues to pose a real risk in our region, even for people who may feel perfectly healthy,” said Dr. Rob Oldham, director of Placer County Health and Human Services. “Most infections are mild, but serious illness can occur, which is why taking steps to avoid mosquito bites is essential.”
Sacramento, Yolo counties report West Nile virus deaths
Four people in the capital region have died from complications of West Nile virus this year, according to the California Department of Public Health — two in each of Sacramento County and Yolo County.
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A person in Sacramento County died Aug. 21 — the Sacramento region’s first West Nile virus death in 2026 — and a Yolo County resident died earlier this month after suffering from neurological complications of the disease, which affect about one in 150 people infected. A Yolo County spokesperson confirmed Wednesday that a second person died in the county but did not provide further details. A Sacramento County representative did not immediately confirm the other death in its jurisdiction.
Six other deaths have been reported throughout California. State data showed three deaths in Butte County, two in Glenn County and one in Kings County.
California health officials as of last Friday had recorded 147 confirmed human cases this year, including 11 in Sacramento County and four in Yolo County. At this point last year, there were only 34 cases statewide, and the five-year average is just over 61 cases.
The Placer Mosquito and Vector Control District said the risk for West Nile virus transmission to humans “remains high,” so residents should get rid of any sources of standing water, contact the district for any issues and apply insect repellent with DEET, picaridin, lemon eucalyptus oil or IR3535. They should also report dead birds at westnile.ca.gov or by calling 1-877-WNV-BIRD.
“As in previous years, our surveillance showed a peak in West Nile virus-positive mosquitoes in mid-summer, with activity typically decreasing as the weather cools,” said District General Manager Joel Buettner. “However, we expect other mosquito species that are not associated with West Nile virus transmission to remain abundant into the fall, and we urge residents to continue protecting themselves from bites by using repellent and wearing protective clothing.”
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This story was originally published September 23, 2026 at 5:04 PM.