A positive case of measles was reported in a Maryland resident who recently traveled internationally, the Maryland Department of Health confirmed on Sunday.

The state's Department of Health said the resident resides in Howard County, but the case is not associated with the measles outbreak in Texas and New Mexico.

The state is working on locating people who may have been exposed, which includes travelers at Terminal A, on the transportation to the main terminal, and in the baggage claim area, between 4 p.m. and 9 p.m. on March 5, 2025.

Measles symptoms typically develop 10 to 14 days after exposure to the virus but can develop as soon as seven days and as long as 21 days after exposure.

According to the Centers for Disease Control and Prevention, there have been three measles outbreaks , defined as three or more related cases, in the United States in 2025.

"It is one of the most infectious diseases that we have," said Dr. Lucia Donatelli, Center for Immunization, Infectious Disease Epidemiology and Outbreak Response Bureau for the Maryland Department of Health. "So, there's a 90% secondary attack rate, we're not fully immunized against measles, there is a 90% chance that if you're exposed that you will contract, measles, so that's why it's so important for everybody to be vaccinated against measles."

People are generally immune to measles if they've had the two vaccine shots, previously had the virus, or were born in the United States before 1957.

Washington Dulles International Airport: Terminal A, on transportation to the main terminal, and in the baggage claim area, between 4 p.m. and 9 p.m. on March 5, 2025.

Johns Hopkins Howard County Medical Center Pediatric Emergency Department, between 3:30 p.m. and 7:30 p.m. on March 7, 2025.

Measles symptoms

Early symptoms of measles are a fever of more than 101 degrees Fahrenheit, runny nose, cough, and red, watery eyes. Usually, one to four days after the early symptoms, a red rash appears on the face and spreads to the rest of the body.

A person with measles is contagious, beginning four days before the rash appears until four days after the rash begins.

People in these at risk groups concerned about potential exposure and that are not immune should contact their health care provider or call Howard County Health Department's Infectious Disease Surveillance and Response Program at 410-313-6284 for additional guidance.

The release states "Measles cases do occur sporadically in Maryland" the most recent cases are one case of measles identified in Maryland in 2024, one in 2023 , and no cases from 2020-2022.