The measles outbreak in South Carolina is “accelerating” with no end in sight following Thanksgiving and other large gatherings, state health officials said Wednesday.
As of Wednesday, 111 measles cases had been reported in what’s known as upstate South Carolina — an area in the northwest of the state that includes Greenville and Spartanburg.
“We are faced with ongoing transmission that we anticipate will go on for many more weeks,” Dr. Linda Bell, state epidemiologist for the South Carolina Department of Public Health, said during a news briefing Wednesday.
Twenty-seven of those cases have been reported since Friday. “That is a significant increase in our cases in a short period of time,” Bell said. She attributed the spike in part to holiday travel and get-togethers, as well as low vaccination rates.
According to NBC News data, the K-12 vaccination rate for measles-mumps-rubella (MMR) in Spartanburg County was 90% for the 2024-25 school year, below the 95% level doctors say is needed to protect against an outbreak. In neighboring Greenville County, the MMR vaccination rate was 90.5%.
The health department deployed mobile health clinics to the area to provide MMR shots, but few people in the community took advantage. “I can tell you that a relatively small number of doses was administered at each of the mobile health unit clinics that we offered,” Bell said.
No other vaccination clinics are planned, according to the department’s website.
People who are not vaccinated are almost always infected after they’re exposed to the virus; measles is the most contagious known virus in the world and can hang in the air for hours.
The current spread in South Carolina is occurring at several schools and a church in Spartanburg County, Bell said, with 254 people under a three-week quarantine. It takes 21 days for symptoms to occur after an exposure.
But with the ongoing spread in schools, some students who remain unvaccinated are now in a second 21-day quarantine since the beginning of the school year, Bell said. She did not have an exact number of kids in their second quarantine, but said it’s not a “significant proportion.”
While the quarantine includes weekends and holidays, 42 days is a significant amount of time away from the classroom.
The spread of measles is not isolated to South Carolina. On Wednesday, the Centers for Disease Control and Prevention reported a total of 1,912 measles cases so far in 2025.
The majority of cases have occurred in unvaccinated children and teenagers.
Outbreaks in the Western U.S. are ongoing: 176 in Arizona and 115 in Utah, according to state health officials. One of the Utah cases occurred at a child care facility with a high school in Salt Lake County.
The infected person was at the facility all day, every day last week (Dec. 1 through Dec. 5), the Utah Department of Health & Human Services said.
And health officials in Montezuma County, Colorado, located on the border of Utah and Arizona, reported an unvaccinated child had been diagnosed with measles. The child had no known connection to any other cases and hadn’t traveled outside of the state.
“The lack of a clear source of infection suggests that unidentified measles cases may be occurring in or traveling” through the area, investigators said.
Symptoms of measles can include:
Headache, fever that may spike to over 104 degrees
Tiny white spots inside the mouth
A rash that begins on the scalp and travels down to the neck, trunk, arms and legs.
Approximately 11% to 12% of measles cases require hospitalization. Three people, including two young girls, have died in the U.S. this year.
MMR vaccines, given in two doses around a child’s first and fifth birthdays, provide 97% protection against the virus.
This article was originally published on NBCNews.com
