The woman, whose identity was not released, was admitted to the hospital in July and remains in serious condition, according to county health officials.
In 2015 in Orange County, 97 people were infected with West Nile, and there were eight West Nile-related deaths, authorities said.
"West Nile Virus is endemic in Orange County, recurring every year during the summer months and continuing into the fall," said county health officer Dr. Eric Handler in a statement. "The best way to avoid West Nile Virus infection is to take precautionary measures to avoid mosquito bites."
Here are some precautions to take against contracting West Nile Virus:
- Emptying all standing water on your property to reduce areas in which mosquitoes may breed, including flower pots and pet bowls.
- Making sure your window and door screens are in good condition.
- Using 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 when outdoors.
Health officials say most people who become infected with West Nile do not experience symptoms, but about 20 percent develop fever and may experience headaches, body aches, nausea, tiredness and sometimes a skin rash.
Those who experience more serious symptoms such as severe headaches, neck stiffness, confusion, muscle weakness or paralysis 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 West Nile, authorities said.
Information on mosquito control and West Nile Virus can be found on the following websites: