At a Glance
- South Carolina measles cases jumped from about 100 to 558 since last fall
- Over 200 new infections emerged in just seven to nine days
- 531 people are under 21-day quarantine after exposure
- Why it matters: The state now hosts the nation’s largest active measles outbreak and health officials warn the toll is “about to get a lot worse”
South Carolina’s measles outbreak is accelerating at an alarming pace. The state’s case count has reached 558 since the first diagnoses last fall, with more than 200 new infections recorded in the past week alone, according to doctors at Prisma Health and the South Carolina Health Department.
Explosive Growth
“Over the last seven to nine days, we’ve had upwards of over 200 new cases. That’s doubled just in the last week,” emergency physician Dr. Johnathon Elkes told reporters Friday. “We feel like we’re really kind of staring over the edge, knowing that this is about to get a lot worse.”
Between Tuesday and Friday the health department confirmed an additional 124 cases, pushing the statewide total to 558. Dr. Robin LaCroix, a pediatric infectious-disease specialist, estimates roughly 200 people are currently infectious.
Hospitalizations and Quarantine
Eight residents-adults and children-have required hospital care for complications since the outbreak began. It remains unclear how many are currently admitted.
Prisma Health would not release details on hospitalized patients’ symptoms, but infectious-disease specialist Dr. Helmut Albrecht noted that admission generally signals critical illness. “Patients don’t get hospitalized if they have red spots,” he said.
Meanwhile, 531 people exposed to the virus are completing mandatory 21-day quarantines.
Hidden Cases
Doctors caution the official tally understates reality. “The numbers that you see are actually an undercount,” said Columbia pediatrician Dr. Deborah Greenhouse. “Not everyone with measles is going to see a physician.”
Measles spreads before symptoms arise; each carrier can infect up to 12 others, according to LaCroix.
Vaccination Gaps Drive Surge
The vast majority of patients are unvaccinated children and teens. The two-dose MMR vaccine is 97% effective, yet coverage in the hardest-hit counties falls short of the 95% threshold needed for community protection.
K-12 MMR vaccination rates, 2024-25 school year:
| County | Rate |
|---|---|
| Spartanburg | 90% |
| Greenville | 90.5% |
Despite free pop-up clinics this week in Spartanburg, only 18 people-nine adults and nine children-received shots.
Cultural Factors
Dr. Eliza Varadi, a South Carolina pediatrician who emigrated from Russia, said resistance is concentrated in a Ukrainian immigrant community where Soviet-era experiences foster vaccine distrust. “I find myself constantly having to explain that, ‘yes, these vaccines are safe,’ and ‘no, they aren’t going to cause harm,'” she explained.
Exposure Alerts
Health officials warned that an infectious individual visited the South Carolina State Museum in Columbia on January 2, a day that drew nearly 1,000 visitors. Unvaccinated attendees risk a 21-day quarantine, though a shot within 72 hours of exposure can avert both illness and isolation.
Regional Spread
The outbreak has crossed state lines:
- Ohio: at least three children diagnosed
- North Carolina: eight cases, seven linked to South Carolina
- Washington: three cases in Snohomish County children who had holiday contact with a visiting South Carolina family
Snohomish County health officer Dr. James Lewis expects more diagnoses but notes the local children, all under age 10, did not require hospitalization.
No Slowdown in Sight
“We have right now the largest outbreak in the U.S., and it’s going to get worse before it gets better,” Albrecht warned.
Key Takeaways
- Measles cases in South Carolina have doubled within a week
- Low vaccination rates in Spartanburg and Greenville counties fuel transmission
- Free MMR shots are available, but turnout remains minimal
- Residents exposed to the virus face a 21-day quarantine unless vaccinated within three days
