The Centers for Disease Control and Prevention is urging Americans to make sure they’re protected against measles before traveling to other countries this summer.
Last week, the agency updated its travel guidance for the virus as cases pop up nationwide. Nearly all exposures at airports are linked to international travel.
That includes six cases linked to a Turkish Airlines flight that landed at Denver International Airport on May 13. The Colorado Department of Public Health and Environment said that four of the patients had been on the plane.
Two other people were exposed at the airport before getting sick. Measles is one of the most contagious viruses in the world. Droplets can linger in the air for up to two hours after an infected person has been there.
According to an NBC News tally, 1,125 measles cases in 33 states have been diagnosed in the U.S. this year. Texas, the state with the largest outbreak, has reported 738 cases.
The numbers are likely vast underestimates, experts say, because many people don’t get tested.
Three people, including two young girls in Texas, have died.
Canada and Mexico are also experiencing outbreaks. The Canadian government said it’s logged 2,515 confirmed or probable cases of measles since the beginning of the year.
Yemen, Pakistan and India top the CDC’s list of countries with the most cases, and the agency notes that measles is a global problem.
“Measles outbreaks are happening in every region of the world. Anyone who is not protected against measles can get measles while abroad and easily spread it to others when they return home,” the CDC wrote on its website.
“Travelers can catch measles in many travel settings including travel hubs like airports and train stations, on public transportation like airplanes and trains, at tourist attractions, and at large, crowded events,” according to the agency’s latest guidance.
People traveling internationally who aren’t vaccinated or who have never had measles “should talk to their clinician and consider postponing their trip,” the agency said.
Babies as young as 6 months old can get an early dose of the measles-mumps-rubella vaccine at least two weeks before international travel, according to the CDC. Older kids and adults who don’t know whether they’ve been vaccinated should get two doses, 28 days apart before a trip.
It takes two weeks to build immunity. After that, people are considered 97% protected against measles infection.
