The Virginia Department of Health says passengers who rode an Amtrak train from Boston to Lynchburg should be looking for symptoms of the measles.
It's believed passengers from the stop in Philadelphia to Lynchburg on Train 171 could have been exposed to the highly contagious illness.
"Quick identification of measles is essential to prevent the spread of this disease," said Frances Philips of Public Health Services.
Amtrak says that the infected passenger boarded train #171 in Philadelphia. The train then made stops at Aberdeen, Penn Station in Baltimore, Baltimore-Washington International Thurgood Marshall Airport and New Carrollton. The train ended its run in Lynchburg at about 8:30 p.m.
Neither Amtrak not health officials are identifying the passenger that reportedly had an active case of measles.
Measles is "highly contagious and anyone not immunized most likely will get it," said Dr. Alison Ansher, director of the Prince William County health department
Measles are highly contagious and can be spread through coughing and sneezing and by contact with nasal, oral or throat secretions from an infected person.
Virginia Health Department spokeswoman Maribeth Brewster said symptoms from an Aug. 17 exposure could develop until Sept. 7.
"Obviously you take the precautions and you use the hand-sanitizer, wash your hands whenever you can but otherwise, I don't worry about germs," said train passenger Anne Delehanty, waiting to board a train at the Alexandria station Monday.
Health Department officials say symptoms like fever, runny nose and coughing would appear in the next few days. Passengers who got off the train before its arrival in Philadelphia would not have been exposed.
To avoid infections when travelling, passengers should "check to see that they have received a immunization against measles, mumps or rubella or the MMR and make sure that all their family members have done the same," recommends Dr. Ansher.
She would be happy to hear Bill Deiss has taken all the precautions. "I'm up on my vaccinations. I think that's just the responsible thing to do," Deiss said.