A San Francisco resident infected with measles traveled to and from work on the BART train for three days—possibly exposing tens of thousands of people, according to reports.

Officials say they are tracking the resident—reportedly a LinkedIn employee—who was diagnosed last week:

In the Bay Area case, the infected person was known to have traveled between the Lafayette station in the East Bay and the Montgomery station in San Francisco during the morning and evening rush-hour commutes on Wednesday, Thursday and Friday of last week, BART spokeswoman Alicia Trost said. That ride is 35 minutes long, but health officials said the highly infectious, airborne virus could have remained in the air for up to two hours. Because BART cars circulate throughout the Bay area, tens of thousands of people could have potentially been exposed, Trost said. The infected rider, who was not identified by name, age or gender, also spent time at the E&O Kitchen and Bar in San Francisco on Wednesday evening, potentially exposing others who were in the restaurant between 5:30 p.m. and 7 p.m., health officials said.

The latest measles outbreak began in December at Disneyland and has since spread to dozens of states with more than 110 cases in California alone.

Hani Durzy, LinkedIn's director of corporate communications, confirmed the story, telling ABC, "We are working very closely with the San Francisco Department of Public Health, and following their recommended protocol for managing this situation."

Great, but the protocol is—and please don't forget this—to vaccinate your damn kids.