With the measles outbreak spreading across the country, a new health advisory has been issued by officials for commuters in the San Francisco area.

Jenna Lee reported on "Happening Now" that Bay Area BART passengers may have been exposed to the highly contagious disease last week from an infected passenger.

According to public health officials in Contra Costa county, the sick passenger used BART to travel between East Bay and San Francisco. The unidentified passenger reportedly traveled before being diagnosed with measles.

The first measles case for Contra Costa County was confirmed by public health officials this week after the outbreak began in December.  

KPIX reported:

The passenger traveled between Lafayette Station and Montgomery Station in San Francisco from February 4-6 from during both the morning and evening commutes from 6 a.m. to 8 a.m. and 7 p.m. to 9 p.m.

The person was also at E & O Kitchen and Bar on 314 Sutter Street in San Francisco on the evening of February 4, between 5:30 p.m. and 7:00 p.m.

Contra Costa Public Health and the San Francisco Department of Public Health were working together to track the person’s movements and notifying people who were in close contact.

Health officials said the person’s employer was cooperating with the San Francisco Health Department to ensure the safety of any employees who may have been exposed.