This is the first confirmed case of the virus in Los Angeles County this year.
Summer and fall are peak seasons for the virus, which is spread to humans who are bitten by an infected mosquito.
Most people who are infected with West Nile do not feel sick, according to the CDC. About 1 in 5 people infected develop a fever and other symptoms, and 1 in 150 people develop a serious -- sometimes fatal -- illness from the virus.
There are no vaccines or medications to treat the virus in people, according to the CDC.
To prevent West Nile, experts recommend using bug repellent and getting rid of any standing water outside your home.