South Carolina is now reporting the worst measles outbreak in the country, as case numbers continue rising rapidly.
State health officials released a statement over the weekend reporting that measles cases jumped nearly 30 percent in just a few days. The state reported 124 new cases since Tuesday, bringing the total to 558 infections.
The outbreak is centered in Spartanburg County, where officials say measles is spreading within the community. Since the holidays, the Upstate outbreak has become the largest active measles outbreak nationwide.
South Carolina first confirmed the outbreak on October 2, 2025. An outbreak is defined as three or more linked cases from a common exposure.
While some infections are tied to travel or known contacts, others have no identified source, signaling ongoing community spread.
Measles spreads through the air when an infected person breathes, coughs, or sneezes. The virus is highly contagious but preventable through vaccination. Health officials warn the disease spreads quickly in unvaccinated households and communities.
Measles was declared eliminated in the U.S. in 2000, but officials say that status is increasingly at risk.
So far in 2026, 171 measles cases have been reported nationwide across nine states, with the largest number of cases being in South Carolina, according to the CDC.
Last year marked the nation’s worst measles spread since 1991. The U.S. reported 2,242 cases in 2025, including 49 outbreaks and three deaths, all among unvaccinated individuals.
State officials continue aggressive response efforts in the Upstate as the outbreak expands.
