South Carolina Confirms Measles Outbreak as U.S. Cases Hit 25-Year High

South Carolina health officials have confirmed a significant measles outbreak concentrated in the Upstate region, contributing to a national surge that has pushed U.S. case numbers to their highest point in a quarter-century. The South Carolina Department of Public Health (DPH) reported on October 1, 2025, that eight measles cases have been identified in the Upstate, with five of those emerging in the last month alone. This cluster prompted the official declaration of an outbreak, which is defined as three or more epidemiologically linked cases.

sc.gov reported, State Epidemiologist Dr. Linda Bell confirmed that the individuals involved in the outbreak were unvaccinated and lacked immunity from any previous measles infection. The announcement has intensified concerns over declining immunization rates and the potential for the highly contagious virus to spread rapidly.

The situation in South Carolina mirrors a troubling nationwide trend. As of late September 2025, the Centers for Disease Control and Prevention (CDC) has recorded 1,544 confirmed measles cases across 41 states, the highest number since 1992 and a stark contrast to the disease's official elimination status declared in 2000. Health officials report that 92% of individuals infected nationwide are either unvaccinated or have an unknown vaccination status.

yahoo.com noted, In response to the Upstate outbreak, the DPH has activated rapid response teams and is conducting extensive contact tracing to notify anyone who may have been exposed. Dr. Bell stated that the unknown source for two of the recent cases points to unrecognized community spread, leading her to anticipate that more cases will be identified. Health authorities are strongly urging all residents to review their immunization records and get vaccinated, emphasizing that the measles-mumps-rubella (MMR) vaccine is the most effective tool for preventing infection.

• Historical Context of Measles Elimination: The United States declared measles eliminated in 2000, a public health achievement credited to a highly effective national vaccination program. Elimination status means the disease has not been continuously transmitted for over 12 months.
• Before the first vaccine was licensed in 1963, measles infected an estimated three to four million people in the U.S. annually, causing 48,000 hospitalizations and 400 to 500 deaths each year. The current national surge, with over 40 outbreaks reported in 2025, now threatens the country's long-held elimination status.
• Details of the South Carolina Outbreak: The eight cases confirmed in South Carolina in 2025 began with two travel-associated cases in July and another in September. However, the five most recent cases, which constitute the current outbreak, include two individuals with no history of travel or known exposure, indicating that the virus is now circulating locally within the Upstate community.
• Dr. Linda Bell, the state epidemiologist, has warned that this community spread poses a significant risk for rapid transmission, especially in areas with low vaccination rates.
• The Science of Measles and Transmission: Measles is a highly contagious viral illness that spreads through the air when an infected person coughs or sneezes. The virus is so potent that it can remain infectious in the air for up to two hours after an infected person has left a room.
• If one person has it, up to 90% of their close contacts who are not immune will also become infected. Symptoms typically appear 7 to 14 days after exposure and include a high fever, cough, runny nose, and red, watery eyes, followed by a characteristic rash that spreads from the face to the rest of the body.
• The Role and Efficacy of the MMR Vaccine: The measles-mumps-rubella (MMR) vaccine is a safe and highly effective method of prevention. Two doses of the MMR vaccine are about 97% effective at preventing measles, providing long-term protection.
• Widespread vaccination creates "community immunity" (or herd immunity), which protects vulnerable individuals who cannot be vaccinated, such as infants, pregnant women, and the immunocompromised. Health officials state that vaccination coverage of 95% is needed to prevent outbreaks.
• Complications and Public Health Risks: Measles is not just a simple rash and can lead to severe complications, especially in children under five and adults over 20. About one in five unvaccinated people in the U.S. who get measles is hospitalized.
• Common complications include ear infections and diarrhea. More severe outcomes include pneumonia, which is the most common cause of death from measles in young children, and encephalitis (brain swelling), which can lead to permanent brain damage or deafness.
• National and Community Implications: The resurgence of measles places a significant strain on public health resources. Responding to an outbreak requires costly and labor-intensive efforts, including contact tracing, laboratory testing, and public awareness campaigns.
• A 2019 measles outbreak in Washington State cost an estimated $3.14 million, or over $47,000 per case, with the public health response accounting for two-thirds of the total. These outbreaks also impact communities by forcing the quarantine of exposed individuals and creating risks in public spaces like schools and childcare centers.
• South Carolina's Public Health Response: The South Carolina DPH is actively working to contain the spread by isolating infected individuals and identifying all potential contacts. The agency is urging anyone who believes they have been exposed or has symptoms to call a healthcare provider before visiting a clinic to prevent further transmission.
• Officials are also reviewing student immunization records to identify potential risks in schools. For the 2023-2024 school year, only 92.1% of kindergarten students in South Carolina had their two required doses of the MMR vaccine, a drop from 95% in 2019-2020, falling below the threshold needed for robust community immunity.