South Carolina measles outbreak becomes largest in the US since 2000

A historic outbreak takes hold in one county

South Carolina’s measles outbreak reached 993 confirmed cases as of March 10, 2026, making it the largest in the United States since the disease was declared eliminated in 2000.

The state’s Department of Public Health reported two new cases that day. The outbreak is centered in Spartanburg County, in the Upstate region of the state.

As of now, 42 people are in quarantine and two are in isolation, with the latest quarantine period set to end April 2.

Outbreak started small, then exploded

The South Carolina Department of Public Health first confirmed the outbreak on Oct. 2, 2025, with eight cases in the Upstate region. It grew slowly at first.

Then, after the winter holidays, it surged, with more than 200 new cases reported per week in January 2026.

Spartanburg County’s school vaccination rate sits at 88.9%, below the state average of 93.7%, according to CDC data. The county is also home to a close-knit community of roughly 15,000 people with low vaccination rates.

Almost all cases are in unvaccinated people

Of the 993 cases, 927 involve people who were not vaccinated against measles. Nineteen people had received just one of the two recommended doses of the MMR vaccine.

Twenty-six cases involve people who had both doses. The vaccination status of 21 people is unknown.

The numbers make a clear case: the overwhelming majority of people who got sick had no vaccine protection at all.

Kids are bearing the brunt of this outbreak

Children make up the vast majority of cases. There are 261 cases in children under the age of 5, and 637 cases in people between the ages of 5 and 17. That adds up to nearly 900 cases in minors alone.

Eighty-six cases involve adults 18 and older. The age of nine people is unknown.

No deaths have been reported in the outbreak.

At least 21 people needed hospital care

At least 21 people, both adults and children, have been hospitalized for complications since the outbreak began. Those complications have included encephalitis, which is swelling of the brain, and pneumonia.

The state health department has noted that complications are not formally reportable, so the real number could be higher. Additional cases required medical care but did not require hospitalization.

The South Carolina Department of Public Health continues to track the full scope of the outbreak.

New cases have dropped sharply

New cases have fallen to roughly 10 per week, down from more than 200 per week in mid-January. State Epidemiologist Dr. Linda Bell said the downward trend is encouraging but cautioned the outbreak is not over.

Bell credited increased vaccination with helping slow the spread. The CDC’s scenario assessment for the outbreak also shows the rate of new cases is now declining.

Still, officials say it is too early to call it finished.

Vaccinations jumped after cases surged

In January 2026, more than 16,800 MMR vaccine doses were given statewide — a 72% increase over January 2025. Spartanburg County saw a 162% jump in vaccinations that same month compared to the year before.

In February 2026, statewide vaccinations rose 70% over February 2025, with Spartanburg County up 133%. Despite those gains, many schools in Spartanburg County still have some of the lowest vaccination rates in the state.

Spring break travel could bring another wave

Dr. Bell warned that spring break travel in late March and April could trigger another spike in cases. Officials pointed to the winter holidays as a precedent, when travel and gatherings fueled the January surge.

Bell said measles does not slow during any particular season the way other respiratory illnesses do.

Unvaccinated people who travel to tourist spots or large gatherings could carry the disease to new communities far outside Spartanburg County.

South Carolina has spent $1.6 million so far

South Carolina has spent an estimated $1.6 million on its public health response to the outbreak, according to data the state health department provided to reporters.

Most of that money has gone toward personnel, with as many as 90 staff assigned full-time to the response.

Those workers have been conducting case investigations and tracing contacts to identify and quarantine exposed people. Final costs will be calculated after the outbreak ends.

This is part of a bigger national problem

As of March 5, 2026, the CDC reported 1,281 confirmed measles cases across 31 states so far this year. That is roughly six times higher than the typical annual total since measles elimination was declared.

The U.S. recorded about 2,283 confirmed cases for all of 2025, the highest yearly total since 1992.

Other active outbreaks continue along the Arizona-Utah border and in several other states, signaling that South Carolina is not an isolated case.

The US could lose its measles-free status

The U.S. has held measles elimination status since 2000, meaning the virus has not spread continuously for more than 12 months.

A review of that status by the Pan American Health Organization, originally set for April 13, has been pushed back to November.

The CDC said the extra time allows for thorough genomic sequencing and analysis of the 2025 outbreaks.

If multiple outbreaks across different states are found to be part of one continuous chain of transmission, the U.S. could lose the designation.

What you can do to protect your family

The MMR vaccine is about 93% effective after one dose and about 97% effective after two. South Carolina requires two doses for school entry from kindergarten through 12th grade.

Adults born in 1957 or later who have not been vaccinated or had measles should talk to a doctor about getting the MMR vaccine.

Measles symptoms include fever, cough, runny nose, red eyes, and a rash that starts on the face and spreads downward.

A person with measles is contagious four days before and four days after the rash appears, and the virus can linger in the air for up to two hours.

This article was created with AI assistance and human editing.

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