The United States is currently facing a resurgence of measles, with the Centers for Disease Control and Prevention (CDC) reporting over 1,900 cases in 2025. The majority of these cases have occurred among unvaccinated individuals. Recent data indicates that 84 new cases were reported nationwide in a single week, marking the highest weekly total since April.

In South Carolina, the situation is particularly alarming, with state health officials noting that more than 250 individuals are currently in quarantine due to potential exposure, and 16 are in isolation due to illness. Some individuals are undergoing quarantine for a second time, as they have not received additional protection through vaccination or natural immunity since their initial exposure. Dr. Linda Bell, the state epidemiologist, emphasized the significant disruption that measles can cause to education and employment, highlighting vaccination as the most effective preventive measure.

The outbreak in South Carolina has resulted in 111 reported cases since October, with at least 105 of those cases occurring in individuals who had not received any doses of the measles-mumps-rubella (MMR) vaccine. The MMR vaccine is recommended in childhood and provides 97% protection against measles infection. Most cases have been concentrated in the upstate region, particularly near Greenville, with exposures linked to gatherings at churches, schools, and medical facilities.

Dr. Bell noted that the highly infectious nature of measles means that each new case in an undervaccinated population can lead to further spread, underscoring the need for increased vaccination coverage to contain the outbreak. In addition to South Carolina, measles cases are also rising in Utah and Arizona, with Arizona reporting 176 cases and Utah 115 cases as of the latest updates.

This year has seen a record number of measles cases in the U.S., with nearly 1,300 cases reported between January and July, the highest since the disease was declared eliminated in the country 25 years ago. If the outbreaks persist into January, the U.S. risks losing its elimination status, similar to Canada, which experienced a similar setback last month. The CDC has recorded 47 outbreaks in 2025, nearly three times the number from the previous year. The outbreaks have resulted in over 200 hospitalizations and three fatalities, including two children.