(Santa Ana, CA) - The first human deaths associated with West Nile virus (WNV) infection in Orange County in 2026 have been confirmed in older adults this week by OC Health Care Agency (HCA) officials. With a severe season and increased cases reported across California, residents and visitors are urged to take precautions to prevent mosquito bites.
Orange County has had 36 WNV infections reported this year. Because about 80% of people infected with WNV have no symptoms, and the majority of cases of West Nile fever do not seek medical care and are not tested, the reported case counts greatly underestimate the number of infected people in Orange County.
Symptoms of West Nile infection include fever, headache, body aches and fatigue. Anyone who develops the more serious symptoms of West Nile neuroinvasive disease such as severe headaches, neck stiffness, confusion, muscle weakness or vision loss should seek medical care immediately. People over 50 years of age and those with underlying medical conditions are at increased risk of serious complications from West Nile virus infection.
“Our hearts go out to the loved ones of those who passed. 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. “This year has been particularly intense, with detections of the virus in humans, mosquitoes, and birds. The recent fatalities show how serious and harmful WNV can be. The best way to reduce the risk of West Nile virus infection is to take measures to avoid mosquito bites and take measures to reduce mosquito breeding around your home.”
Recommended WNV precautions include:
- Emptying all standing water on your property to eliminate areas in which mosquitoes may breed, including flowerpots and pet bowls.
- Making sure your window and door screens are in good condition.
- Using Environmental Protection Agency (EPA) registered insect repellent containing DEET, picaridin, oil of lemon eucalyptus, or products containing IR3535, always following label directions.
- Limiting outdoor activity at dawn and dusk, when mosquitoes are most active.
- Wearing long-sleeved shirts and long pants outdoors.
Most people who become infected with WNV do not experience symptoms, but about 20% will develop fever and may have headache, body aches, nausea, tiredness and sometimes a skin rash. More serious symptoms, such as severe headaches, neck stiffness, confusion, muscle weakness, or paralysis, occur more rarely, but people who develop these symptoms should seek medical care immediately. People over 50 years of age and those with certain medical conditions are at increased risk of serious complications from WNV infection.
Information on mosquito control is available on the Orange County Mosquito and Vector Control District website at www.ocvector.org. Other websites with helpful information about WNV include:
- Centers for Disease Control and Prevention: CDC West Nile Virus
- State of California: California Department of Public Health - West Nile Virus
- State of California WNV Testing: West Nile and St. Louis Encephalitis Viruses in CA: Guidelines for Human Testing, Surveillance, and Reporting
- OC Health Care Agency: West Nile Virus | Orange County California - Health Care Agency
- OC Health Care Agency: Mosquitoes More Than Just a Nuisance
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ABOUT THE OC HEALTH CARE AGENCY
The OC Health Care Agency (HCA) is a regional interdisciplinary health jurisdiction and an accredited health department, charged with protecting and promoting individual, family and community health through partnership and coordination of public and private sector resources. Visit www.ochealthinfo.com to learn more about services and resources.