The Centers for Disease Control and Prevention confirmed Wednesday that a person who lives in Yolo County has tested positive for Zika virus, according to Yolo County.
Yolo County officials say the individual recently traveled out of the country and had a mild case of Zika.
Zika virus has spread to 20 countries in Central and South America and the Caribbean, including Mexico.
Zika is spread through mosquito bites, not casual person-to-person contact.
The CDC says symptoms are usually mild and last several days to a week.
There is currently no vaccine or treatment for Zika.
Pregnant women, however, are believed to be most at risk for complications from the Zika virus because serious birth defects have been reported in infants born to women infected with the virus.
The CDC has a webpage dedicated to providing information about the Zika virus, including areas where the virus is on-going.