South Carolina health officials yesterday said the state now has 434 measles cases after 124 new cases have been confirmed.

There are currently 409 South Carolinians in quarantine and 17 in isolation, with some quarantines extending to February 6. Mobile vaccine units will be active this week, and officials urge local residents to get vaccinated.

“Vaccination now can avoid long quarantines at home for those exposed to the measles virus. Vaccination within 72 hours of exposure can prevent measles infections,” the state’s department of public health said in its update.

Almost all cases come from the Upstate region in an outbreak centered in Spartanburg County that began in October and has involved exposures at several schools and churches. Spartanburg County is home to several charter schools with a significant number of students with religious exemptions from routine vaccinations.

In South Carolina, religious exemption from vaccination requires a notarized form but not a doctor’s note. One of the schools involved in the initial weeks of the outbreak, Global Academy of South Carolina, had only a 17% vaccination rate during the 2024-25 school year.

Of the 434 measles patients tracked in the past six months, 378 are unvaccinated and 47 have unknown vaccination status. Only six patients have been fully vaccinated, and three have been partially vaccinated. Two-thirds of all measles case-patients in South Carolina are between the ages of 5 and 17 (287 cases).

Utah cases crack 200

South Carolina now has the largest measles outbreak in the country, and the second largest outbreak recorded in the past year in the United States. A West Texas outbreak that began last January and was declared over in August saw 762 cases. More than two-thirds of the West Texas cases were in children, including two fatalities in school-aged children.

In other measles news, Utah has 25 new cases, raising the state total to 201. Southwest Utah has the most cases, at 147, followed by Utah County with 24 cases, and Wasatch County with 9 cases.

Arizona officials yesterday confirmed three new measles cases in the state, all from this year. All three are in Mohave County, which has seen a lingering cross-border outbreak with Southwest Utah for several months. Arizona’s outbreak has now reached 217 infections.