US has already had more measles cases in 2024 than all of 2023

The number of measles cases reported in the U.S. so far this year has already surpassed the total number of infections counted in 2023.

According to data released by the Centers for Disease Control and Prevention (CDC), 64 confirmed and suspected cases of measles had been reported across 17 states as of March 21. Last year, 58 total cases were reported in 19 states and Washington D.C.

This year's case count hasn't yet smashed records seen in the past decade. 2014 and 2019 stand out as particularly bad years, with more than 660 and 1,200 measles cases apiece; these high numbers partly stemmed from major outbreaks tied to Disneyland and to underimmunized, close-knit religious communities.

However, measles cases have rebounded significantly since 2020, when only 13 infections were reported in the U.S. And internationally, Austria, the Philippines, Romania and the U.K. are experiencing outbreaks, the CDC cautioned in a recent health advisory.

Related: Measles deaths jumped over 40% from 2021 to 2022, CDC reports

"Given currently high population immunity against measles in most U.S. communities, the risk of widescale spread is low," the advisory reads. "However, pockets of low coverage leave some communities at higher risk for outbreaks."

At the time of the advisory, issued March 18, 58 of this year's measles cases had been confirmed by the CDC. The vast majority, over 90%, were tied to international travel, the CDC reported, while some have been tied to domestic travel to Florida, according to CBS. Most cases were reported in unvaccinated children ages 1 year and older.