A measles outbreak in the upstate of South Carolina has necessitated the quarantine of 153 unvaccinated children for at least 21 days. This measure aims to curb the spread of the virus among students who have not received vaccinations.

Meanwhile, in Minnesota, a small outbreak that has been expanding over the past month has resulted in the quarantine of 118 students in the Minneapolis-St. Paul region. Health officials confirmed this on Friday, acknowledging the significant number of exposures to the highly contagious virus.

The restrictions mean three weeks of remote learning as parents monitor for fever, rash and other symptoms.

Michael Osterholm, an infectious disease expert and director of the Center for Infectious Disease Research and Policy at the University of Minnesota, remarked on the situation, saying, “Communities are having to bear the price of quarantining so many children. Expect more of the same. This is going to happen more and more frequently.”

Active, ongoing transmissions

The South Carolina Department of Public Health reported on Thursday that a case of measles had been diagnosed in Greenville County, separate from seven other cases identified in adjacent Spartanburg County.

Dr. Linda Bell, state epidemiologist for the South Carolina Department of Public Health, commented during a Thursday press briefing, “What this new case tells us is that there is active, unrecognized community transmission of measles occurring.”

In South Carolina, the cases have been pinpointed in two schools: one is an elementary school, and the other is a charter school catering to students from kindergarten through 12th grade.

Unvaccinated children who were exposed to the virus will be “excluded” from school for three weeks, the length of time it could take for a measles exposure to cause symptoms, Bell said.

“Those measures will help us be effective in preventing the spread of measles virus in those schools and in our communities,” she said.

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%.