South Carolina measles outbreak threatens US elimination status

South Carolina is experiencing the largest measles outbreak in United States history since the disease was declared eliminated in 2000. As of January 30, the state's Department of Public Health confirmed 847 cases, surpassing the previous record set by a Texas outbreak in 2025. The rapid spread is happening across 17 states and jurisdictions nationwide, with health officials warning that the United States could lose its measles elimination status if the outbreak continues to accelerate.

The outbreak, which began in October in South Carolina's Upstate region, has grown exponentially in recent weeks. In just one week in late January, cases jumped by 90 percent, with 89 new infections reported in a single update. The speed of transmission has alarmed public health experts, who point to declining vaccination rates as the primary driver of the crisis.

Background

Measles was declared eliminated from the United States in 2000 following decades of widespread vaccination campaigns that brought childhood immunization rates above 95 percent. The disease had killed hundreds of Americans annually before the vaccine became standard. For more than two decades, the country maintained its elimination status, with only sporadic cases linked to international travelers.

That success began to unravel in 2025, when the nation recorded 2,255 measles cases across the year—the largest number in three decades. This year's outbreak in South Carolina is spreading far faster than last year's national numbers. The state alone has already recorded cases that exceed the entire 2025 Texas outbreak, which had been the largest in recent memory.

The outbreak is not contained to South Carolina. At least 17 states have reported measles cases since January 1, including Arizona, California, Florida, Georgia, Idaho, Kentucky, Minnesota, Nebraska, North Carolina, Ohio, Oregon, South Dakota, Utah, Virginia, Washington, and Wisconsin. Nationally, 588 cases have been confirmed so far in 2026, meaning the country has recorded more measles cases in one month than is typically seen in an entire year.

Key Details

Vaccination rates tell the story of the outbreak. Among the 789 cases documented in South Carolina as of January 27, 695 people were completely unvaccinated. Only 20 people were fully vaccinated, while 14 were partially vaccinated. The remaining 60 cases had unknown vaccination status. Across the outbreak, 88 percent of cases involved unvaccinated individuals.

Nationally, the picture is similar. The Centers for Disease Control and Prevention reports that 94 percent of measles cases across the country are either unvaccinated or have unknown vaccination status. This pattern reflects a troubling trend in childhood immunization rates that has been declining for years. Vaccination rates among school-age children fell from 95 percent in 2019 to 92 percent in 2023, according to health data.

School Exposures and Community Spread

The outbreak is no longer limited to close contacts of known cases. Health officials have identified multiple public exposure sites, indicating that measles is spreading through the general community. Schools have become particular hotspots. As of late January, students from at least seven schools were in quarantine, including Holly Springs-Motlow Elementary with 59 students quarantined, Campobello Gramling School with 46 students, and Libertas Academy with 28 students in isolation.

More than 400 people were in quarantine across South Carolina as of late January, with the latest quarantine dates extending into mid-February. Health officials have identified new exposures at additional schools, including Dorman High, Inman Intermediate, and New Prospect Elementary.

Severity and Hospitalizations

While most measles cases resolve on their own, the outbreak has produced serious complications. At least 18 people, including both children and adults, have required hospitalization for measles-related complications since the outbreak began. Additional cases required medical care without being hospitalized. The age breakdown shows that children bear the heaviest burden: 203 cases involved children under 5 years old, and 493 cases involved children aged 5 to 17.

"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.

What This Means

The outbreak poses a direct threat to the United States' measles elimination status. The disease spreads through the air and can remain infectious for up to two hours after an infected person leaves a space. With vaccination rates below the 95 percent threshold needed for community immunity, the virus finds ample opportunity to spread.

Losing elimination status would represent a significant public health setback. It would mean the United States could no longer claim to have eradicated a disease that once killed hundreds of Americans annually. The designation carries international implications as well, affecting how other countries view American disease control efforts.

Health officials emphasize that vaccination remains the most effective way to stop the outbreak. Vaccines are available at primary care offices, pharmacies, and health department locations. The MMR vaccine requires two doses and provides protection against measles, mumps, and rubella. For those who are unvaccinated or unsure of their status, getting vaccinated is the primary defense against infection.

The South Carolina outbreak serves as a warning about the consequences of declining vaccination coverage. As immunization rates continue to fall, the conditions become increasingly favorable for diseases that were once controlled to resurface and spread rapidly through communities.