SANTA ANA, Calif. (CNS) — Orange County Friday announced its first West Nile virus infection for this year.

A man tested positive recently, according to the Orange County Health Care Agency. It’s unknown how he is doing or when he tested positive.

Last year, there were three West Nile infections and no virus-related deaths in the county.

“It’s pretty rare,” Andrew Noymer, an epidemiologist and UC Irvine professor of population health and disease prevention, said of the disease.

Dr. Matthew Zahn, the deputy county health officer, said, “West Nile virus is endemic in Orange County, recurring every year during the summer months and continuing into the fall.”

Zahn said the “best way to avoid West Nile virus infection is to take precautionary measures to avoid mosquito bites.”

The virus is spread by insects, mostly mosquitoes, and can infect humans, birds, horses and other mammals. Most people do not fall ill when they get it, but about 20% do experience flu-like symptoms.

Residents are encouraged to dump any standing water on their property, because that’s where mosquitoes breed.