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

On Monday, South Carolina public health officials announced the conclusion of the largest measles outbreak in the U.S. since 1991.

On Sunday, the state reached 42 consecutive days without reporting any new cases related to the outbreak. Over a six-month period beginning last October, 997 individuals in South Carolina contracted measles, primarily unvaccinated children. At least 21 people required hospitalization due to complications from the disease.

The outbreak was mostly confined to the state’s northwest region, avoiding a statewide spread. This was attributed to prompt investigations, identification of those exposed, and people’s cooperation in staying home, according to Dr. Edward Simmer, interim director of the South Carolina Department of Public Health. He described the response as a textbook example of managing an outbreak.

The measles virus can cause severe complications like pneumonia and brain swelling. Dr. Brannon Traxler of the South Carolina Department of Public Health stated during a Monday briefing that while many measles cases were mild, others faced life-threatening or potentially long-lasting effects.

Measles can be deadly. Last year, three individuals, including two school-aged children in Texas, died from the disease. Though most recover, measles can lead to prolonged complications such as immune amnesia, where the virus diminishes parts of the immune system, making children susceptible to new infections for years. Furthermore, children infected before age two are at a heightened risk of developing a fatal degenerative neurological condition that generally emerges seven to ten years post-infection.

In South Carolina, the outbreak was concentrated in Spartanburg County, where most schools had vaccination rates below the 95% required to prevent outbreaks. Traxler noted the outbreak was halted partly due to increased vaccination uptake. Measles is among the most contagious diseases known.

However, Traxler cautioned that pockets of unvaccinated individuals remain in Spartanburg County and across the state, posing ongoing risks.

Dr. Martha Edwards, president of the South Carolina chapter of the American Academy of Pediatrics, reported that pediatricians have seen previously hesitant families return to request the measles vaccine after witnessing the disease’s impact on their community.

“Families that experienced measles communicated that it was not an easy illness,” she said. “It was really tough, and they were genuinely concerned.”

Though South Carolina’s outbreak has ended, more than 20 new outbreaks have been reported this year across the U.S., according to the Centers for Disease Control and Prevention. These include significant outbreaks in Texas, Florida, and Utah, each with over 100 confirmed cases.

The resurgence of measles in the U.S. coincides with declining vaccination rates nationwide. According to the CDC, 92.5% of kindergartners received the measles vaccine in the 2024-2025 school year. However, in many communities, the vaccination rates are much lower, creating conditions conducive to outbreaks. Experts warn that a single spark can ignite these outbreaks.

Last year, the U.S. reported 2,288 cases of measles, the highest since 2000 when the disease was declared eliminated in the country. This designation is given to countries that have gone a year without ongoing transmission.

This status is now at risk. With 1,792 measles cases confirmed so far this year, according to the CDC, the U.S. is on track to surpass last year’s record number of cases.