The measles outbreak in South Carolina continues to grow, with state health officials warning that transmission is increasing and could persist for weeks, particularly following holiday travel and large gatherings.
As of yesterday, the South Carolina Department of Public Health reported 135 confirmed measles cases in the state’s Upstate region, which includes Greenville and Spartanburg counties. Nine new cases have been identified since last Friday alone.
State epidemiologist Dr. Linda Bell said ongoing transmission is expected to continue, citing low vaccination rates and increased movement around Thanksgiving as contributing factors. Health officials have emphasized that measles spreads easily in communities where immunization levels fall below the threshold needed to prevent outbreaks.
According to available data, measles-mumps-rubella (MMR) vaccination rates in Spartanburg County stood at 90% during the 2024–25 school year, while neighboring Greenville County reported a rate of 90.5%. Public health experts generally consider a 95% vaccination rate necessary to prevent sustained community spread. As a result of exposure, some unvaccinated students in the affected areas have entered a second 21-day quarantine since the start of the school year, amounting to more than six weeks away from classrooms when consecutive quarantines are required.
South Carolina’s outbreak is part of a broader national rise in measles cases. The Centers for Disease Control and Prevention reported 1,912 measles cases across the United States so far in 2025. Most cases have occurred among unvaccinated children and teenagers.
Several western states are also reporting active outbreaks. Arizona has recorded 176 cases, while Utah has reported 115. In Utah, one case involved exposure at a child care facility connected to a high school in Salt Lake County, where the infected individual was present throughout the week of December 1–5, the Utah Department of Health & Human Services said. In Colorado’s Montezuma County, an unvaccinated child was diagnosed with measles despite no known travel or links to other cases, prompting officials to warn that undetected transmission may be occurring in the region.
Measles symptoms typically include high fever, cough, runny nose, red or watery eyes, and a characteristic rash that begins on the scalp and spreads downward. Tiny white spots inside the mouth can also appear early in the illness. Health officials note that approximately 11% to 12% of measles cases result in hospitalization. Three deaths have been reported in the U.S. this year, including two young children.
The MMR vaccine, administered in two doses around a child’s first and fifth birthdays, is estimated to be 97% effective at preventing measles. Public health agencies continue to urge vaccination as the most effective way to stop the spread and reduce the risk of severe illness.
(AI was used in part to facilitate this article.)