State Disease Outbreak: 997 Cases Reported With Zero Deaths

U.S. Declares End to Largest Measles Outbreak in 35 Years After Nearly 1,000 Cases in South Carolina

Health officials in South Carolina have officially declared the end of the state’s measles outbreak—the largest in the United States in more than three decades. The outbreak, which began in October 2025, infected 997 people and resulted in 21 hospitalizations, though no deaths were reported. After 42 consecutive days without a novel case linked to the outbreak, state authorities confirmed its conclusion on Monday, April 27, 2026.

The response to the outbreak, which was largely contained within a single county, cost an estimated $2.1 million, according to state health officials. The financial burden included contact tracing, vaccination campaigns, and public health interventions aimed at preventing further spread. Dr. Edward Simmer, acting director of the South Carolina Department of Health and Environmental Control (DHEC), credited the containment efforts to rapid investigations, the identification of exposed individuals, and community cooperation in adhering to isolation guidelines.

“This outbreak was a stark reminder of how quickly measles can spread in under-vaccinated communities,” Dr. Simmer said in a statement. “Our ability to contain it to a specific geographic area, rather than allowing it to spread statewide, was due to the swift actions of our health teams and the willingness of residents to follow public health recommendations.”

The Outbreak’s Scope and Impact

The measles outbreak in South Carolina was the most severe in the U.S. Since 1991, when a resurgence of the virus led to more than 2,200 cases nationwide. The 2025-2026 outbreak in South Carolina accounted for nearly half of all U.S. Measles cases reported during that period, according to data from the Centers for Disease Control and Prevention (CDC). While the state avoided fatalities, the 21 hospitalizations underscored the virus’s potential severity, particularly for vulnerable populations such as young children, pregnant women, and individuals with compromised immune systems.

Measles is one of the most contagious viruses known to medicine, with an estimated basic reproduction number (R₀) of 12 to 18. So that, on average, one infected person can spread the virus to 12 to 18 others in a fully susceptible population. The virus spreads through respiratory droplets and can remain airborne for up to two hours after an infected person leaves an area. Symptoms typically appear 7 to 14 days after exposure and include high fever, cough, runny nose, and a characteristic red rash that begins on the face and spreads downward.

While most people recover from measles within two to three weeks, complications can be severe. According to the CDC, about 1 in 5 unvaccinated people who contract measles will be hospitalized. Common complications include ear infections (which can lead to permanent hearing loss), pneumonia (the most common cause of measles-related death), and encephalitis (swelling of the brain), which can result in long-term neurological damage or death. Pregnant women who contract measles are at higher risk of premature birth or low birth weight.

Public Health Response and Costs

The $2.1 million spent on containment efforts in South Carolina reflects the extensive resources required to manage a measles outbreak. These costs included:

• Contact tracing to identify and notify individuals exposed to the virus.
• Vaccination clinics to administer the measles, mumps, and rubella (MMR) vaccine to unvaccinated or under-vaccinated individuals.
• Public education campaigns to inform residents about measles symptoms, transmission, and prevention.
• Enhanced surveillance to monitor new cases and prevent further spread.

The outbreak’s financial toll highlights the economic burden of vaccine-preventable diseases on public health systems. A 2019 study published in JAMA Pediatrics estimated that each measles case costs public health agencies approximately $142,000 when accounting for direct medical costs, outbreak response, and lost productivity. The South Carolina outbreak’s total cost aligns with these estimates, given the nearly 1,000 cases reported.

Dr. Simmer noted that the outbreak’s containment was aided by the state’s existing immunization infrastructure, which allowed health officials to quickly identify and vaccinate at-risk individuals. “We were fortunate to have a robust public health system in place, but this outbreak also exposed gaps in vaccination coverage in certain communities,” he said. “Moving forward, we must prioritize outreach to ensure all residents, especially children, are up to date on their vaccines.”

Why Measles Outbreaks Are Resurging in the U.S.

The South Carolina outbreak is part of a broader trend of measles resurgences in the U.S. And globally. After being declared eliminated in the U.S. In 2000, measles has made a comeback in recent years, driven by declining vaccination rates and international travel. The CDC reported 1,274 measles cases in the U.S. In 2019, the highest number since 1992. While cases declined during the COVID-19 pandemic due to reduced travel and social distancing, outbreaks have since rebounded as restrictions eased.

Several factors contribute to the resurgence of measles:

• Vaccine hesitancy: Misinformation about vaccine safety, particularly regarding the MMR vaccine, has led some parents to delay or refuse vaccination for their children. Despite overwhelming scientific evidence that the MMR vaccine is safe and effective, concerns about a debunked link to autism persist in some communities.
• Global travel: Measles remains endemic in many parts of the world, including Europe, Africa, and Asia. Travelers can unknowingly bring the virus into the U.S., where it can spread in under-vaccinated communities.
• Vaccination gaps: Some communities have vaccination rates below the 95% threshold needed to achieve herd immunity, leaving them vulnerable to outbreaks. In South Carolina, vaccination rates for kindergarteners were 93.6% for the 2023-2024 school year, slightly below the national average.

The MMR vaccine, which protects against measles, mumps, and rubella, is highly effective. Two doses of the vaccine are about 97% effective at preventing measles, while one dose is about 93% effective. The CDC recommends that children receive their first dose at 12 to 15 months of age and their second dose at 4 to 6 years of age. Adults who are unsure of their vaccination status or were born after 1957 should receive at least one dose of the MMR vaccine, unless they have evidence of immunity.

Lessons from the Outbreak

The South Carolina outbreak serves as a cautionary tale for public health officials and communities nationwide. While the state’s response was largely successful in containing the virus, the outbreak’s scale and cost underscore the importance of maintaining high vaccination rates. “This was a preventable crisis,” said Dr. Anne Schuchat, former principal deputy director of the CDC, in an interview with NPR. “Measles is not a benign disease, and outbreaks like this one are a wake-up call for all of us.”

Health officials in South Carolina are now focusing on post-outbreak efforts, including:

• Conducting vaccination audits in schools and childcare centers to identify and address gaps in immunization coverage.
• Launching targeted outreach campaigns to communities with low vaccination rates, including underserved and rural populations.
• Strengthening partnerships with local healthcare providers to ensure they are equipped to recognize and report measles cases promptly.

The state is also collaborating with the CDC to analyze the outbreak’s origins and identify potential improvements for future public health responses. Preliminary investigations suggest that the outbreak may have been sparked by an unvaccinated traveler who contracted the virus abroad and returned to South Carolina, though the exact source remains under review.

What’s Next for Measles Prevention in the U.S.?

The end of the South Carolina outbreak does not signal the end of measles risks in the U.S. Public health experts warn that without sustained efforts to improve vaccination rates, similar outbreaks could occur in other states. The CDC continues to monitor measles activity nationwide and has issued guidance for travelers, recommending that all individuals ensure they are up to date on their MMR vaccinations before international travel.

For parents and caregivers, the South Carolina outbreak highlights the importance of following the CDC’s recommended vaccination schedule. “Vaccines are one of the most powerful tools we have to protect our children and communities from preventable diseases,” said Dr. Peter Hotez, co-director of the Texas Children’s Hospital Center for Vaccine Development, in a Scientific American op-ed. “The consequences of vaccine hesitancy are real, and we are seeing them play out in outbreaks like this one.”

As of April 2026, the CDC reports that measles cases in the U.S. Have declined compared to the peak of the South Carolina outbreak, but sporadic cases continue to be reported in other states. The agency urges all Americans to check their vaccination status and consult their healthcare providers if they are unsure whether they are protected against measles.

Key Takeaways

• Outbreak scale: The South Carolina measles outbreak infected 997 people and resulted in 21 hospitalizations, making it the largest in the U.S. In 35 years.
• Containment efforts: The outbreak was contained within a single county, thanks to rapid public health interventions and community cooperation.
• Cost of response: The state spent an estimated $2.1 million on outbreak response, including contact tracing, vaccination clinics, and public education.
• Vaccine effectiveness: The MMR vaccine is 97% effective after two doses, making vaccination the best defense against measles.
• Global resurgence: Measles outbreaks are increasing worldwide due to vaccine hesitancy, global travel, and gaps in vaccination coverage.
• Prevention: Maintaining high vaccination rates is critical to preventing future outbreaks and protecting vulnerable populations.

How to Stay Informed and Protected

For the latest updates on measles activity in the U.S., readers can visit the CDC’s measles webpage, which provides real-time data on cases and outbreaks. The World Health Organization (WHO) also offers global measles surveillance reports and vaccination guidelines.

Individuals who are unsure of their vaccination status can request their immunization records from their healthcare provider or state health department. The CDC’s vaccine information page provides detailed guidance on the MMR vaccine, including who should obtain vaccinated and when.

As the U.S. Moves forward from the South Carolina outbreak, public health officials emphasize that the fight against measles is far from over. “This outbreak was a reminder of what can happen when vaccination rates drop,” said Dr. Simmer. “Our goal now is to ensure that every community in South Carolina—and across the country—is protected against this preventable disease.”

The next official update on measles activity in the U.S. Is expected from the CDC in June 2026, when the agency will release its quarterly surveillance report. In the meantime, health officials encourage all Americans to prioritize vaccination and stay informed about measles risks in their communities.

What are your thoughts on the recent measles outbreak and the importance of vaccination? Share your comments below and join the conversation on how we can work together to prevent future public health crises.