COLUMBIA, Md. — Although measles was considered "eliminated" from the U.S. 25 years ago, in recent years, epidemiologists could see the writing on the wall. Vaccination rates were starting to dip in the U.S., and cases were beginning to rise globally. An outbreak was likely.
"It's the most contagious germ that we know of," Dr. James Campbell, a pediatric infectious disease specialist at the University of Maryland Children’s Hospital and a professor at the University of Maryland School of Medicine, said. "90% of people who are susceptible who are in the same room within 2 hours of somebody who has measles will get measles."
"So you only need a small proportion of susceptible individuals or unvaccinated individuals in order for the virus to spread and cause outbreaks," Dr. William Moss, epidemiology professor at the Johns Hopkins Bloomberg School of Public Health, told WMAR-2 News.
IN FOCUS: Reported measles cases by year
And that's what we're seeing in Texas and New Mexico, where the majority of the 222 cases reported by the CDC have been located. Most of the patients are unvaccinated school-aged children.
There is now one case confirmed in Maryland, a Howard County resident who recently traveled abroad. The Maryland Department of Health says this case is not associated with the outbreaks elsewhere in the U.S.
"There has been an uptick of measles globally, really since the pandemic," Dr. Campbell said.
The doctors we spoke to say the good news for Marylanders is that our state has a vaccination rate that's higher than the national average.
"Close to 97%, whereas the national average is somewhere below 93%," Dr. Moss said.
So in the past, when there's been a singular case of measles—like in 2023 and 2024—it has remained just a singular case. However, the concern lies in communities where the vaccine coverage might be significantly lower than the rest of the state.
"Those few percent that are not, sometimes they cluster together," Dr. Campbell said.
But even if there are small communities in Maryland with lower vaccine coverage rates, Dr. Moss said, "I think we’re in pretty good shape."
The state health department put out the following warning over the weekend:
Anyone who visited the following locations during any of the following hours may have been exposed:
Washington Dulles International Airport: The international arrivals area
- March 5th, 4:00 pm - 9:00 pm
Johns Hopkins Howard County Medical Center Pediatric Emergency Department
- March 7th, 3:30 pm - 7:30 pm
Dr. Campbell explained that just because a disease is considered "eliminated" from the U.S. doesn't mean it's not around at all:
"By definition we’ve ‘eliminated’ measles from the United States, but that definition is not the same as if you look it up in Webster’s dictionary. Elimination by public health officials means measles has not continuously circulated for more than a year across the United States. That doesn’t mean there are no cases of measles. It means enough people are protected against measles that when it’s reintroduced, it doesn’t continue to spread for more than a year."
He said the belief that measles is not a threat is sometimes the reason why people choose not to get the MMR vaccine for themselves or their children.
"And for those who might have chosen in the past not to be vaccinated because they thought measles was not around, so they didn't think their child needed the first or the second shot, it's around; it's going to come back again probably," Dr. Campbell said. "Measles vaccines have been around since the 1960s, and getting two doses of MMR, the measles mumps rubella vaccine, is 97% protective against measles, so essentially you get lifetime and nearly complete protection. It’s nearly as good as having had measles in terms of how it protects you."
When will we know if the disease has spread in Maryland? Dr. Campbell told WMAR-2 News: "The incubation period is pretty long, so it’ll be a while before we know whether or not there are other cases. It’s usually about two weeks after exposure that you come down with measles."
If you believe you were exposed to measles and you start to experience symptoms, the Maryland Department of Health asks you to call your doctor before showing up to a waiting room or an ER so they can take measures to prevent the spread to other patients.
