BART spokespeople sent a rather alarming message to media Thursday afternoon, saying that East Bay passengers might have been exposed to the measles.

According to BART spokesman Jim Allison, "a person infected with the contagious disease traveled on BART in the East Bay last week. The Centers for Disease Control and Prevention (CDC) says measles has been virtually wiped out in the United States thanks to vaccinations but the disease still poses a risk to those who have not been vaccinated."

A KQED compilation of California Department of Health data suggests that Bay Area parents are choosing not to vaccinate their children against diseases like the measles in greater and greater numbers, making this a real concern for many BART riders.

Allison says that "the person infected with measles traveled between El Cerrito del Norte and Downtown Berkeley stations on Tuesday, February 4 through Friday, February 7 between 8 to 10 am and in the afternoon/evening commute hours."

Measles is an airborne virus that can remain in the air for as long as two hours. According to the CDC, "measles is so contagious that if one person has it, 90% of the people close to that person who are not immune will also become infected with the measles virus."

Symptoms typically kick in between a week to two weeks after infection. If you think you might have been exposed, and you have any symptoms, which include:

Blotchy rash
Runny nose
Red, watery eyes
Feeling run down, achy
Tiny white spots with bluish-white centers found inside the mouth

...Then stop reading this and go to the doctor right now. We're not messing around here, this disease can be fatal.

Update: BCN/ reports that the infected person is a UC Berkeley student who "was not vaccinated and was likely infected with the disease during a recent trip abroad." The student also "spent time in the Berkeley community" and "attended classes on the UC Berkeley campus."