South Carolina has recorded the most confirmed measles cases so far this year, as the United States continues to struggle with outbreaks.
Some 616 cases of measles have been confirmed in South Carolina in 2026, according to the Centers for Disease Control and Prevention (CDC).
This is by far the highest number, followed by 63 in Florida and 44 in Utah.
Why It Matters
Measles was declared eliminated in the United States in 2000, but falling vaccination coverage, increasing global measles activity and travel-related importations have driven a sharp rise in cases and outbreaks, threatening vulnerable communities and straining public health response, said the CDC.
Some 90 percent of this year’s confirmed 910 cases are outbreak-associated, underscoring how quickly the virus can spread.
What To Know
In the past week, 177 new cases were recorded across the country–up from 733 total cases recorded on February 5, and now to 910 total cases on February 12.
Six of these total cases were reported among international visitors while 904 were reported across the following 24 states:
- Arizona
- California
- Colorado
- Florida
- Georgia
- Idaho
- Kentucky
- Maine
- Minnesota
- Nebraska
- New York City
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- South Carolina
- South Dakota
- Utah
- Vermont
- Virginia
- Washington
- Wisconsin
There have been five new outbreaks this year but the majority of cases (760) are from outbreaks that started in 2025.
South Carolina has recorded 616 cases in the the six weeks of this year. Comparatively, Texas recorded a total of 803 cases in the whole of 2025.
Multiple states have recorded zero cases this year, with Colorado, Nebraska, Oklahoma and Georgia recording just one.
What Causes Measles
Measles is caused by a highly contagious virus that spreads through the air when an infected person breathes, coughs, or sneezes, and people can become infected simply by being in a room where a person with measles has been, according to the CDC.
Measles Symptoms in Children and Adults
Early symptoms often include fever, cough and runny nose for seven to 14 days after exposure, followed by tiny white spots in the mouth (Koplik spots) and then a characteristic rash, and people are contagious before the rash appears, according to Harvard Medical School.
Complications can include pneumonia, encephalitis, hearing loss, and, rarely, fatal outcomes, with severe disease more likely in children under 5, adults over 20, pregnant people, and those with weakened immune systems.
What to Know About Measles Vaccine
The MMR vaccine is described by the CDC as very safe and effective, and when more than 95 percent of people in a community are vaccinated, community immunity helps protect those who cannot be vaccinated, federal guidance says.
Breakthrough infections among fully vaccinated people are uncommon and typically milder, and approximately 10 percent of all measles infections occur in vaccinated individuals during outbreaks, consistent with prior years, according to the CDC.
What Happens Next
The CDC will continue weekly updates of national measles case counts and outbreak status, and state and local health departments will publish the most current jurisdiction-level information, with counts subject to revision as investigations progress.
Public health officials will emphasize vaccination, rapid case isolation, contact tracing, and post-exposure prophylaxis, and will use modeling to identify high-risk communities where declining MMR coverage could fuel additional outbreaks.
