Orange County has confirmed 36 human West Nile virus cases so far this year, compared with one at the same point in 2025, according to the Orange County Health Care Agency. The county recorded three cases last year.
The county's figures, current through Sept. 24, list no West Nile deaths. However, the family of a 61-year-old Anaheim man told ABC7 that he died this month after contracting the virus, a death that does not yet appear in the county's official count.
The increase matters for households across one of Southern California's most populous counties. Most infections cause no symptoms, but a small share become serious, and older adults and people with certain medical conditions face the greatest risk.
A Sharp Climb in County and State Counts
In August, the California Department of Public Health said West Nile activity had reached its highest level in five years. As of Sept. 18, the state's West Nile tracking site listed 147 human cases and 10 deaths across 21 counties, up from 117 cases at the same point last year.
County and state totals do not match. The state site listed 10 Orange County cases as of Sept. 18, while the county reported 36 six days later. The county's own count is more recent, and state tallies can lag behind local reporting.
Mosquito testing shows the same trend. On Sept. 15, a spokesperson for the Orange County Mosquito and Vector Control District said 718 of the district's mosquito nets had tested positive for the virus this year, compared with 70 at the same point in 2025, CBS Los Angeles reported. "This is a fire-alarm year for mosquitoes," the spokesperson said.
The district scheduled overnight spraying for adult mosquitoes in Anaheim, Costa Mesa, and Garden Grove. The spokesperson told CBS the ultra-low-volume treatment uses about two tablespoons of product per acre and, at that rate, will not harm people.
All 10 deaths reported by the state as of Sept. 18 were in Central Valley counties: Butte, Glenn, Kings, Sacramento, and Yolo. If the Anaheim death is confirmed, it would be the first West Nile death on Orange County's official 2026 count.
One Family's Warning and an Uncounted Death
Daniel Clavel of Anaheim fell ill in August, ABC7 reported. He developed a rash, was later found unconscious at home, and spent 24 days in intensive care before he died.
"He left us for people to be aware," his wife, Tracey, told the station.
The county had not added his death to its West Nile count as of Sept. 24. Deaths can take time to be reviewed and added to official figures. Until the county updates its count, the case remains a family account rather than an official statistic.
Adults Over 50 and People with Chronic Conditions
About 1 in 5 infected people develop fever, headache, body aches, nausea, or fatigue, according to the county. A much smaller number develop neuroinvasive disease, which affects the brain and spinal cord and can cause severe headache, stiff neck, confusion, muscle weakness, or paralysis.
"West Nile virus is endemic in Orange County, recurring every year during the summer months and continuing into the fall," County Health Officer Dr. Regina Chinsio-Kwong said when the county reported its first 2026 case on Aug. 5.
The county says people over 50 and those with certain medical conditions face a higher risk of serious illness. That makes older relatives, people with chronic conditions such as diabetes or high blood pressure, and anyone with a weakened immune system the priority for protection, especially if they spend evenings outdoors or live near standing water.
There is no vaccine or specific antiviral treatment for West Nile virus in people. Care for severe illness is supportive, so preventing bites is the main defense.
Severe cases also make up a large share of reported infections nationally. MedicalDaily previously reported that seven in ten reported West Nile cases this year have been neuroinvasive. That partly reflects testing patterns, since the sickest patients are the most likely to be tested, but it shows how often reported cases involve serious illness.
"People should be concerned," the vector control district spokesperson told ABC7, urging residents who are outside at dusk and dawn to wear repellent.
Mosquito Season Is Not Over Yet
County health officials say the virus circulates through the summer and into the fall, so the risk has not passed. The county recommends emptying standing water in places such as flowerpots and pet bowls, keeping window and door screens in good repair, and using EPA-registered repellent with DEET, picaridin, oil of lemon eucalyptus, or IR3535.
Wearing long sleeves and pants and limiting time outside at dawn and dusk also lowers risk. Residents can contact the Orange County Mosquito and Vector Control District about mosquito problems.
Anyone with a sudden severe headache, stiff neck, confusion, or weakness after mosquito exposure should seek medical care promptly. Milder fevers and body aches still warrant a call to a health care provider, particularly for older adults and people with chronic illnesses.
Sept. 24, 2026: Orange County reports 36 human cases and no official deaths. ABC7 reports that an Anaheim man's family says he died after contracting West Nile virus.
Sept. 18, 2026: California reports 147 cases and 10 deaths statewide.
Aug. 5, 2026: Orange County confirms its first human case of the year in Anaheim.
Key Questions Answered
How many West Nile cases does Orange County have? The county reports 36 human cases as of Sept. 24, compared with one at the same point in 2025.
Has anyone died? The county's official page lists no deaths. An Anaheim man's family told ABC7 he died after contracting the virus, but the county had not added the death to its count as of Sept. 24.
Why do state and county numbers differ? The county's figures are more recent, and state tallies can lag behind local reporting.
Who faces the highest risk? People over 50 and those with certain medical conditions.
What are the warning signs of severe illness? Severe headache, stiff neck, confusion, muscle weakness, or paralysis.
How can I protect my family? Empty standing water, use EPA-registered repellent, repair screens, and cover up and limit time outdoors at dawn and dusk.
Published by Medicaldaily.com
