California residents are being warned by health officials that they were potentially exposed to measles after a college student commuted on Bay Area Rapid Transit (BART) during rush hour this month.
The unidentified University of California, Berkeley student likely contracted the illness during a recent trip to Asia.
Health officials issued a warning last Thursday that commuters on BART from Feb. 7 to Feb. 10 could have been exposed.
BART gives an average of 390,000 rides in one workday.
Officials also warned Berkeley students who shared classrooms with the infected student.
"Measles is a serious, highly contagious disease," Dr. Janet Berreman, health officer for the city of Berkeley, said in a statement. "It spreads through the air when an infected person coughs or sneezes. Fortunately, the measles vaccine is highly effective in preventing infection."
The virus can remain in the air for up to two hours.
The university ordered 300 shots of the Measles, Mumps, Rubella vaccine for students who haven’t received it.
The MMR vaccine put an end to measles in the United States in 2000, but cases are on the rise as more individuals refuse vaccinations for themselves and their children. A movement that claims MMR causes autism, has led to a resurgence of the measles. Polio and whooping cough are also on the rise.
An estimated 1,300 people have died since June 3, 2007, from vaccine-preventable diseases like measles, mumps, and rubella.