Orange County Health Care Agency officials have confirmed the county’s first human West Nile case of 2026, which some medical experts believe could be one of the worst mosquito seasons on record.
It’s already the third reported human case in Southern California, after Long Beach and Los Angeles health officials reported their first cases in late June and July.
The patient has only been identified as an Anaheim resident, HCA officials said.
“West Nile virus is endemic in Orange County, recurring every year during the summer months and continuing into the fall,” said a statement from Orange County Health Officer Dr. Regina Chinsio-Kwong. “There have been multiple detections of WNV-positive mosquitoes in Orange County, signaling that this could be an intense WNV season. The best way to avoid West Nile virus infection is to take precautionary measures to avoid mosquito bites.”
A map from Orange County Vector Control shows that Anaheim, Cypress, Buena Park and Fullerton are among the county’s hotspots for mosquitoes that have tested positive for the virus. Officials are concerned that this year’s numbers could surpass the county’s worst-ever recorded numbers in 2014, when nine people died.
“We are concerned that with the high activity detected in the mosquitoes, that people are likely to be at risk of getting sick for getting sick from West Nile virus,” said the Orange County Vector Control lab director, Amber Semrow.
So far in 2026, more than 300 West Nile virus-positive samples have been collected from mosquitoes, more than two times higher than the 2014 numbers, which vector control officials referred to as an epidemic, as they had more cases than anywhere in the nation.
Health care officials said that most people who become infected with the virus don’t show symptoms, but approximately 20% of people will develop fever and may get headaches, body aches, nausea, tiredness and sometimes a skin rash. Serious symptoms, which are more rare, can include severe headaches, neck stiffness, confusion, muscle weakness or paralysis.
People over 50 and those who have certain medical conditions are at an increased risk of serious complications, HCA’s release said.
Residents were advised to empty standing water on their property, make sure window and door screens are in good condition, use insect repellant, limit outdoor activity at dusk and dawn or wear long sleeves when outdoors to limit risk of contracting the virus.
“A lot of times we tell people dump and drain … get rid of that standing water. That’s still true,” said OC Vector Control spokesperson Brian Brannon. “But, with mosquitoes flying around with West Nile virus, you also need to put on repellant at dusk and dawn. You need to protect yourself from getting that disease, which can be deadly.”
More information on Orange County Vector Control and mosquito mitigation efforts can be found on their website
