Health officials confirmed Friday that a Contra Costa County resident visiting Berkeley libraries may have had the measles virus.

The adult, who has not been confirmed to have measles, visited Berkeley’s Central Branch Library on the afternoon of Feb. 27 and was at the West Branch Library throughout the day Feb. 27 and Feb. 28, according to a news release.

The Berkeley public health division is working with the libraries to notify and evaluate those who might have been exposed. Library patrons who visited during those dates should monitor themselves for symptoms until March 21, according to the release.

Since December 2014, California has been experiencing a large outbreak of measles that has reached several Bay Area counties, including Alameda County. There have been at least 132 confirmed cases statewide and at least six confirmed cases in Alameda County, according to the California Department of Public Health.

Measles, a highly contagious and airborne disease, can stay in the air for up to two hours after an infected person coughs or sneezes. Symptoms usually begin with a fever, followed by a runny nose, cough and rash, which begins typically on the face and spreads to the rest of the body.

People who have received the recommended two doses of the measles vaccine are at low risk, according to health officials.

“I encourage Berkeley community members to make sure they and their children have received the required two doses,” said Dr. Janet Berreman, Berkeley’s health officer, in the news release. “Obtaining records of your vaccination could prove critical in the event of a local outbreak.”

Contact Amy Jiang at [email protected] and follow her on Twitter @ajiang_dc.