West Nile Virus Hits Orange County Hard: 36 Cases This Year, Health Officials Urge Precautions
Santa Ana is a city in Orange County, California. The Orange County Health Care Agency (HCA) has confirmed a severe West Nile virus (WNV) season this year, with 36 human infections reported and the first WNV-related deaths of 2026 confirmed. Health officials urge residents to take mosquito precautions, as mosquito season is not over yet.
The season began on Aug. 5, when an Anaheim resident tested positive, becoming the first human WNV infection in Orange County this year. "West Nile virus is endemic in Orange County, recurring every year during the summer months and continuing into the fall," said Dr. Regina Chinsio-Kwong, County Health Officer. "There have been multiple detections of WNV positive mosquitoes in Orange County, signaling that this could be an intense WNV season."
By late September, the county had reported 36 human infections. In late September, HCA confirmed the first human deaths associated with WNV infection in 2026, both in older adults. A 61-year-old Anaheim man died after contracting the virus and spending 24 days in intensive care.
Health officials note that because about 80% of people infected with WNV have no symptoms, and most West Nile fever cases do not seek medical care or get tested, reported case counts greatly underestimate the actual number of infections.
Symptoms of West Nile infection include fever, headache, body aches and fatigue. About 20% of infected people develop these symptoms. Anyone who develops serious symptoms of West Nile neuroinvasive disease — severe headaches, neck stiffness, confusion, muscle weakness or vision loss — should seek medical care immediately. People over 50 and those with underlying medical conditions face higher risk of serious complications.
There is no human vaccine for WNV and no specific antiviral treatment; preventing bites is the only reliable protection. HCA recommends:
- Emptying all standing water around your property (flowerpots, pet bowls) to reduce mosquito breeding areas
- Keeping window and door screens in good repair
- Using EPA-registered insect repellent containing DEET, picaridin, oil of lemon eucalyptus, or IR3535
- Limiting outdoor activity at dawn and dusk, when mosquitoes are most active
- Wearing long-sleeved shirts and long pants outdoors
Mosquito control information is available on the OC Mosquito and Vector Control District website.
Sources: OC Health Care Agency, Medical Daily (September 2026)
Published by GSM · USA (original Chinese edition)
Photo: Wikimedia Commons, CC BY-SA 3.0, 作者 Walkabout12
