The measles outbreak is in South Carolina over but more are starting elsewhere : NPR

A health care worker examined a patient with measles symptoms in Spartanburg, South Carolina, in January. Strict public health measures and increased vaccination have helped curb the outbreak.

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South Carolina public health officials declared the largest measles outbreak in the United States since 1991 over on Monday.

On Sunday, the state marked 42 days without any new cases linked to the outbreak. Over a six-month period beginning last October, 997 people were infected with measles in South Carolina. Most of them were unvaccinated children. At least 21 people have been hospitalized for measles-related complications.

The outbreak has been largely confined to the northwest region of the state. It was never broadcast statewide, “thanks to timely investigations, identification of exposed individuals and people’s willingness to stay home,” said Dr. Edward Simmer, acting director of the South Carolina Department of Public Health. “In many ways, this was a classic response to dealing with an epidemic.”

The measles virus can cause serious complications, including pneumonia and brain swelling. At a briefing Monday, Dr. Brannon Traxler of the South Carolina Department of Public Health said that while many cases of measles are mild, “it is sometimes life-threatening or can be long-lasting for others.”

Measles can be fatal. Last year, three people – including two school-age children in Texas – died from the disease. Although most people recover from measles, it can cause long-term complications, including immune amnesia, a phenomenon in which the virus destroys parts of the immune system, leaving children vulnerable to new infections for several years.

And children infected before age 2 are at higher risk of developing a fatal degenerative neurological disease that typically develops seven to 10 years after measles infection.

South Carolina’s outbreak was centered in Spartanburg County, where the majority of schools had measles vaccination rates below the 95% threshold required to prevent outbreaks. Traxler says the state has managed to stop the outbreak, in part due to an increase in the number of people getting vaccinated. Measles is one of the most contagious diseases known.

But Traxler says pockets of people without immunity — acquired either through measles infection or vaccination — remain in Spartanburg County and across the state, “so there’s an ongoing risk there.”

Dr. Martha Edwards, president of the South Carolina chapter of the American Academy of Pediatrics, says she’s heard from pediatricians who had previously hesitant families returning to seek the measles vaccine after seeing the disease’s impact on their community.

“I think the families who suffered from measles kind of made it known that it wasn’t such an easy disease,” she says. “It was really hard, they were really worried.”

Although the outbreak in South Carolina is over for now, more than 20 other new outbreaks have been reported this year in the United States, according to the Centers for Disease Control and Prevention. This includes large outbreaks in Texas, Florida and Utah, each with more than 100 confirmed cases of measles.

The resurgence of measles in the United States comes as vaccination rates are falling across the country. Nationally, 92.5% of kindergartners received the measles vaccine in the 2024-2025 school year, according to the CDC. In many communities across the country, these numbers are much lower, creating the conditions for measles outbreaks to spread. Experts say all it takes is a spark to ignite it.

Last year, the United States reported 2,288 cases of measles, the highest number since 2000, when the disease was declared eliminated from the country. This is a technical designation given to countries that have gone a year without a continuous chain of transmission.

This status is now under threat. With 1,792 measles cases confirmed so far this year, according to the CDC, the United States is on pace to surpass last year’s record number of cases.