South Carolina health officials today said the state now has 188 cases of measles, 185 of which are associated with a growing outbreak in the Upstate region linked to elementary schools with low vaccination rates. 

As of late last week, 223 people were in quarantine for measles exposure. “Four of the new cases were known household exposures, one resulted from a previously reported school exposure, the source of three cases is unknown, and one is still being investigated,” officials said. 

Of the 185 case-patients in the Upstate outbreak, 172 are unvaccinated, 4 have unknown vaccination status, and only one patient was fully vaccinated. Forty of the patients in the outbreak are under age 5, and 123 are between ages 5 to 17.

Ongoing outbreaks in South Carolina, Arizona 

South Carolina is now likely to follow Arizona in reaching the 200-case mark at the start of the new year. Arizona has 205 cases currently, with neighboring Utah tracking 156 cases. Many of the cases in those two states are linked to an outbreak in Mohave County, Arizona, and Southwest Utah.

At the end of December, the United States passed the 2,000-case milestone and could soon lose its measles elimination status, first obtained in 2000.