Passengers on San Francisco’s Bay Area Transit Authority (BART) subway system were exposed last week to the measles.
Officials with the agency said a passenger who has the measles virus rode one of its trains prior to being diagnosed.
The agency said passengers should watch for symptoms of the virus, even as they stressed the risk of other passengers becoming infected is very low.
{mosads}“Contra Costa Public Health officials confirmed this week the county’s first measles case since the statewide outbreak began in December and issued an advisory today after learning the person traveled on BART before being diagnosed,” the agency said. “Most people are not at risk since they are vaccinated against measles, but anyone who is not vaccinated is at risk to be infected if exposed to the virus. BART uses industrial-strength disinfectant to clean its trains at the end of the line during the day and each night.”
BART is the fifth-busiest subway system in the U.S., trailing only networks in New York, Washington, Chicago and Boston. The transit system carries about 422,000 passengers on average weekdays on 104 miles on track.
The agency said the passenger who is carrying the measles “traveled between the Lafayette Station and Montgomery Street Station during the morning and evening commutes from 6 to 8 am and 7 to 9 pm on Wednesday, Thursday and Friday, February 4-6.
“Contra Costa Public Health and the San Francisco Department of Public Health are working together on investigating the person’s movements and notifying people who were in close contact,” the agency said. “The person’s employer is cooperating fully with the San Francisco Health Department to ensure the safety of any employees who may have been exposed.”
BART officials said “people who are vaccinated or have had measles before are extremely unlikely to catch measles, even if they had contact with a contagious person.”
The agency warned passengers who have not been vaccinated to be mindful, however.
“Those who were not previously vaccinated are at high risk if exposed,” BART said. “Measles is a serious, highly contagious disease that is spread through the air when an infected person coughs or sneezes.
“Because the measles virus can stay in the air for up to two hours and BART cars circulate throughout the Bay Area, anyone who used the transit system during that time could have potentially exposed to the virus,” the agency continued. “Health officials urge anyone who shows symptoms of measles to contact their healthcare provider immediately.”