In the past week, South Carolina officials have confirmed 212 new measles cases, raising the state total to 646 and threatening to overtake last year’s West Texas outbreak as the largest in decades in the United States.
There are currently 538 people in quarantine and 33 in isolation, the South Carolina Department of Public Health said today. Six schools have recent public exposures that have resulted in new quarantines.
The outbreak centered in Spartanburg County has been primarily rooted in elementary and secondary schools that have large portions of unvaccinated students. Now two universities have reported new infections and exposures, with officials saying Clemson University has 34 students in quarantine, and Anderson University has 50 in quarantine. Each school has reported one confirmed measles case.
Among the South Carolina cases, 563 patients are unvaccinated, 12 are partially vaccinated, 13 are fully vaccinated, and 58 have unknown status. Of the 646 case-patients, 155 are under the age of 5 years, and 419 are between the ages of 5 and 17.
The South Carolina outbreak is now the largest in the country and will likely surpass the 762-case West Texas outbreak that began one year ago today, putting the United States at risk of losing its measles elimination status. That outbreak was declared over in August 2025.
Washington outbreak linked to South Carolina
Now officials in Washington state have confirmed that three measles cases in a family from Snohomish County are linked to an exposure from a South Carolina family who visited multiple locations in King and Snohomish counties over the holidays.
The three cases, in unvaccinated siblings aged 23 months to 9 years, are the state’s first measles cases since 2023.
Additionally, one person in Kittitas County has also been confirmed to have measles. This is Kittitas County’s first measles case in at least 18 years, and the patient is a student at Central Washington University.
PAHO to assess elimination status
In related news, the Pan American Health Organization’s (PAHO’s) Regional Monitoring and Re-Verification Commission for Measles, Rubella, and Congenital Rubella Syndrome has formally invited the United States and Mexico to a virtual meeting on April 13 to review their measles elimination status.
The meeting date has been set to give national health authorities and national sustainability committees sufficient time to prepare comprehensive reports
“The meeting date has been set to give national health authorities and national sustainability committees sufficient time to prepare comprehensive reports, including descriptions and analyses with detailed epidemiological and laboratory evidence, for review by the Commission,” PAHO said.
Measles elimination status may be lost if the commission finds uninterrupted measles transmission chains lasting for more than 12 months in both countries. The two countries experienced the beginning of large measles outbreaks in January and February of last year.
In the United States, there has been debate if current measles cases can be traced to last year’s West Texas outbreak. The current South Carolina outbreak began in October, with other states seeing spikes in activity throughout the year, including a large outbreak on the Arizona-Utah border that has sickened more than 200 people.
Scientists have confirmed the same measles strain in Texas, New Mexico, Utah, Arizona, South Carolina, Canada, and Mexico, a PAHO spokesperson told NPR.
The United States first achieved measles elimination status in 2000.
