South Carolina health officials said the state’s measles outbreak has grown by nearly 100 cases over three days, prompting additional quarantine and isolation orders.
The outbreak centered in Spartanburg County, where it grew to 310 cases over the holidays. Officials said families who traveled to the outbreak area in northwestern South Carolina during the school break have also been linked to cases in North Carolina and Ohio.
Health officials acknowledged that the rise in cases had been expected after holiday travel and family gatherings during the school break. They said the surge is being driven by a growing number of public exposure sites and low vaccination rates in the area.
As of Friday, state health department data showed 200 people were in quarantine and nine were in isolation. Dr. Linda Bell, who leads the state health department’s outbreak response, said the quarantine count did not capture the full number of exposures.
“The number of those in quarantine does not reflect the number actually exposed,” Bell said. She added: “An increasing number of public exposure sites are being identified with likely hundreds more people exposed who are not aware they should be in quarantine if they are not immune to measles.”
Bell has warned since the outbreak began in October that the virus was spreading undetected in the area. She said hundreds of school children have been quarantined from school, some more than once.
South Carolina was one of two active measles hot spots, with the other outbreak on the Arizona-Utah border. In that region, officials reported 337 people had gotten measles since August.
Last year, the U.S. confirmed 2,144 measles cases across 44 states, according to Centers for Disease Control and Prevention end-of-year data cited by the Associated Press. Health experts said measles is on the verge of making a lasting comeback in the U.S. as the one-year anniversary of the Texas-New Mexico-Oklahoma outbreak approaches.
Experts said that if transmission continues, the U.S. would lose its status of having eliminated local spread of measles, as Canada did in November. International health experts said the same strain of measles is spreading across the Americas.