U.S. Measles Cases Near 100, Up Nearly 70% From 2023

Measles has surged in the U.S. over the past three months, as cases in places like Chicago, Florida and Philadelphia have driven the total number of infections nationwide well above the tally for all of 2023.

A total of 97 cases had been reported across 17 states as of March 28, according to the most recent figures from the Centers for Disease Control and Prevention. That’s a 67% increase from a total of 58 for all of 2023.

So far, a total of seven outbreaks – defined by the CDC as three or more related cases – have been reported for 2024, up from four in 2023. More than 70% of all cases this year have been associated with an outbreak, while more than half of the 97 cases involved children under 5, according to the CDC.

Over 70% of those infected were either unvaccinated or had received just one dose of measles, mumps and rubella vaccine.

Many measles cases have occurred in the Chicago area, where an outbreak at a migrant shelter had fueled an overall total of 52 cases as of Friday, according to provisional data from the Chicago Department of Public Health. In Florida, 11 measles cases have occurred this year, according to reports, with many tied to spread among students at an elementary school in Broward County. State health officials on March 8 announced the infection period tied to the school cases had ended.

The rise in measles cases in the U.S. and globally prompted the CDC to issue an advisory on March 18 urging parents to get their children two doses of the measles, mumps and rubella vaccine, which has been shown to be 97% effective.

And though the level of measles vaccination coverage overall may prevent a massive outbreak from occurring, public health experts remain concerned about potential outbreaks in clusters of vulnerable communities where vaccination rates are low.