Topline
South Carolina’s growing measles outbreak is now the largest in United States history since the contagious viral disease was declared eliminated more than two decades ago in the wake of widespread vaccinations, according to a report from CNN.
Key Facts
As of Tuesday, 789 cases have been reported, according to data from the South Carolina Department of Public Health.
State health officials said Tuesday at least 18 adults and children have been hospitalized with measles-related complications, with no deaths reported.
600 of these cases have come in 2026 alone.
Measles is a fast-spreading viral illness tied to symptoms like fever, cough, and a red rash.
692 of the infected patients are unvaccinated, according to the department.
Cases are concentrated among children in the 5-11 age group, followed by infants and toddlers 0-4 years old.
Almost all cases (756) are located in the upstate county of Spartanburg, which has more than 350,000 people and is among the most-populated counties in South Carolina, according to the Census Bureau.
Big Number
88%. That’s the proportion of measles cases in South Carolina that have appeared in unvaccinated individuals, according to statistics shared by the state health department.
Crucial Quote
“We feel like we’re really kind of staring over the edge, knowing that this is about to get a lot worse,” said Dr. Johnathon Elke of South Carolina-based Prisma Health at a press briefing early this year.
Key Background
Measles cases have been booming in South Carolina since the start of the new year. As of last Friday, the state health authority had confirmed 416 cases since it began tracking the outbreak in late September. The updated count represents an increase of 90% in under a week. Childhood vaccinations against measles have been declining, according to Harvard Health. Rates among school-age kids fell from 95% in 2019 to 92% in 2023. The spread is happening at a faster rate than the 2025 nationwide outbreak, when the highly contagious disease made its biggest comeback in three decades, resulting in 2,255 confirmed cases for the year, according to data from the CDC.