South Carolina measles outbreak tops 300 cases, spreads beyond state lines

Empty desks, fast spread

SPARTANBURG, S.C. — In a Spartanburg County elementary school this month, nearly half a fifth-grade class stayed home, ordered into 21 days of quarantine after a classmate was diagnosed with measles. The desks sat empty, but the virus that once seemed a relic of another era was very much present — in classrooms, church pews and family living rooms across South Carolina’s Upstate.

State health officials on Jan. 9 reported 99 new measles cases since earlier in the week, bringing the total linked to an ongoing outbreak to about 310. It is among the largest state-level measles outbreaks since the United States declared the disease eliminated in 2000 and has already seeded cases in at least two other states.

“This is not a small flare-up,” Dr. Linda Bell, South Carolina’s state epidemiologist and incident commander for the response, said when the latest figures were released. “The number of those in quarantine does not reflect the number actually exposed. We know there are hundreds more people exposed who are not aware they should be in quarantine if they are not immune to measles.”

How the outbreak grew

The outbreak is centered in Spartanburg County in the Upstate region and has unfolded as the United States recorded its worst measles year in decades. It is testing South Carolina’s school vaccine rules, religious exemption policies and the country’s ability to maintain its measles “elimination” status in the face of rising hesitancy toward shots that were once routine.

Health officials first signaled trouble last fall. Through the summer of 2025, the South Carolina Department of Public Health confirmed several scattered measles infections, many tied to international travel. On Sept. 26, the department reported a case in an unvaccinated Upstate resident with no known exposure — a red flag that the virus might be spreading quietly.

On Oct. 2, the department formally declared a measles outbreak in the Upstate after confirming eight cases in the region, five of them epidemiologically linked. All were unvaccinated and lacked evidence of prior immunity. Within days, the state launched a dedicated outbreak website and began issuing twice-weekly updates.

The numbers climbed steadily:

• Oct. 17: 19 measles cases statewide for the year; 15 linked to the Upstate outbreak; 84 people in quarantine.
• Oct. 24: 25 total cases; new infections largely among household contacts already being monitored.
• Mid-November: 49 outbreak cases; some new patients had no known exposure source, confirming community circulation.

The outbreak accelerated in December. On Dec. 12, the health department announced 15 new cases in a single update, for an outbreak total of 126. At least 11 schools in and around Spartanburg County — including elementary, middle and high schools — had documented exposures. More than 300 people were in quarantine, and mobile health units were dispatched to offer free measles, mumps and rubella (MMR) vaccinations in affected neighborhoods.

When schools reopened after winter break, case counts surged again. In a Jan. 6 update, the department reported 26 new cases since the previous Friday, bringing the outbreak total to 211. The age breakdown underscored how heavily the virus was hitting children: of those 211 patients, 45 were under 5 years old and 143 were 5 to 17. Only 17 were adults.

Who is getting sick

Vaccination status data has shown the outbreak is concentrated among people without immunity.

As of the Jan. 6 update, 196 of the 211 people infected — more than 90% — were unvaccinated. Four had received one dose of MMR, one was fully vaccinated, and vaccination status for the rest was unknown or under investigation.

“Vaccination continues to be the best way to prevent measles and stop this outbreak,” the department said in its Jan. 6 release, urging parents to check their children’s records and consider immunization even if they had previously claimed exemptions.

The most recent spike, announced Jan. 9, pushed the total to about 310 outbreak-related cases. According to data reported by the state and confirmed by national news agencies, 256 of those patients were unvaccinated and only two had documentation of full vaccination. At least four people — including children and adults — have been hospitalized. No deaths have been reported.

Cases linked in other states

The outbreak has not stayed within South Carolina’s borders.

On Dec. 31, the North Carolina Department of Health and Human Services reported a presumed measles case in an unvaccinated child from Polk County, just across the state line. The child had visited locations in Spartanburg County identified in South Carolina’s outbreak notices. North Carolina officials called it the state’s second measles case of 2025 and explicitly linked it to “a large ongoing measles outbreak in Upstate South Carolina.”

Less than a week later, on Jan. 6, North Carolina authorities announced three additional pediatric cases in siblings from Buncombe County. The family had traveled to Spartanburg County one to two weeks before the children became ill. One child visited the emergency department at Mission Hospital in Asheville while infectious, prompting the hospital and health officials to alert people who were in the waiting room during specific hours.

National wire services have reported that Ohio has also identified measles cases in families who recently traveled to the outbreak area in northwestern South Carolina. As of early January, federal health officials said all confirmed U.S. measles cases in 2026 were tied to ongoing outbreaks, including South Carolina’s.

Elimination status and why vaccination levels matter

Measles was declared eliminated in the United States in 2000, meaning the virus no longer spread continuously year-round in the country, even though cases still occurred from international importations. That status is assessed by the Pan American Health Organization using criteria that include whether a single strain circulates for more than 12 months.

The South Carolina outbreak is unfolding after a year in which the United States reported 2,144 measles cases and 49 separate outbreaks, according to federal surveillance data — the highest national case count since at least the early 1990s. Large clusters in Texas and along the Arizona-Utah border, as well as the Upstate South Carolina outbreak, have prompted health officials to analyze viral genetic sequences to show the events are driven by separate introductions rather than one prolonged chain of transmission.

In November, Canada lost its measles elimination status after authorities documented sustained transmission over a full year. U.S. officials have said they are working to present evidence this year that, despite the high case numbers, measles has not become reestablished nationally.

Measles is among the most contagious human viruses; public health experts say that to prevent outbreaks, about 95% of people in a community must be immune, mainly through vaccination.

South Carolina’s most recent school immunization data show that 92.1% of kindergartners received the recommended two doses of MMR vaccine in the 2023-24 school year, a decline from roughly 95% before the COVID-19 pandemic. About 4.4% of kindergartners have exemptions from at least one required vaccine, and another 4.5% are enrolled under grace-period or provisional status — meaning they are not yet fully vaccinated but do not hold exemptions.

Federal data show the share of U.S. kindergartners protected with two doses of MMR has fallen to 92.7%, the fourth straight year below the 95% target. Exemptions from any vaccine are at a record high of 3.3%, with nonmedical exemptions accounting for nearly all of the increase.

Quarantines, exemptions and the response

South Carolina law allows only medical and religious exemptions for school and childcare vaccines; personal or philosophical objections are not recognized. Parents seeking religious exemptions must sign a state certificate, typically obtained through a local health department. The same law authorizes schools and public health officials to exclude students who are not immune during an outbreak until it is safe for them to return.

Those provisions are now being used extensively. Students who are unvaccinated or lack proof of immunity and were exposed to measles at school have been told to stay home for 21 days after their last exposure, sometimes repeatedly if new cases are identified. The Department of Public Health has asked employers to be flexible with parents who need to stay home to care for quarantined children.

The state’s response has included rapid laboratory testing, intensive contact tracing, public notices of exposure sites, and expanded opportunities to get vaccinated. Mobile clinics have parked outside schools, churches and community centers in Spartanburg County to offer free MMR shots without appointments.

What comes next

Health officials say those measures can slow the outbreak but cannot instantly compensate for years of gradual slippage in vaccination coverage, in South Carolina and nationally.

For families in the Upstate, the consequences are immediate: missed school days, lost work, and anxiety about a disease that can cause pneumonia, encephalitis and, in rare cases, death — particularly in young children.

Bell has repeatedly urged residents to view the outbreak as a reminder of measles’ seriousness rather than a distant statistic.

“We are seeing widespread community transmission in an area where many people are not protected,” she said. “We still have an opportunity to prevent further spread — but that depends on people knowing their vaccination status and taking steps to protect themselves and their families.”

As winter continues and the last rounds of quarantines are scheduled to end, health officials say the virus’s eventual toll in South Carolina will depend less on what happens in laboratories and command centers than on everyday decisions in doctors’ offices, schools and homes — whether parents bring children in for delayed shots, whether pastors and community leaders encourage immunization, and whether a disease once pushed to the brink of disappearance can again be kept in check.