A person with measles traveled through the District of Columbia while contagious, city health officials said Tuesday, marking the city’s first recorded infection this year.
The individual traveled on Amtrak’s Northeast Regional route heading southbound on March 19 and walked through the concourse at Union Station between 11:00 p.m. and 1:30 a.m.
The person sought treatment at an urgent care facility three days later, the DC Health Department said. The agency is informing people who were at these locations that they may have been exposed.
Measles is highly contagious, but high vaccination rates stop it from spreading. Measles was officially eliminated in 2000 due to a highly effective vaccination program, but it’s not uncommon for states to see a handful of cases every year tied to travel.
Most measles cases in the U.S. are initially introduced by an unvaccinated person exposed during international travel who then brings the virus back to spread among undervaccinated communities at home.
Earlier this month, Maryland reported three cases of measles connected to international travel.
Measles is preventable through a safe and effective vaccine. Two doses of the vaccine are given to provide lifetime protection. However, infants younger than 12 months of age are too young to be vaccinated.
According to health officials, it takes the body about 14 days after vaccination to develop immunity to measles, so people aren’t considered vaccinated until that 14-day period has passed.
The latest data from the Centers for Disease Control and Prevention show 378 people in 18 states have been diagnosed with measles this year.
The case in D.C. does not appear to be connected to a growing outbreak in Texas, Oklahoma and New Mexico. To date, 327 cases have been reported in Texas alone, almost entirely linked to unvaccinated people or people whose vaccination status is unknown.
Just two cases were reported in people who were vaccinated.
In the Texas outbreak, children and teenagers between ages 5 and 17 make up the majority of cases, followed by children ages 4 and under.