Sustained increase in measles cases prompts the Americas to strengthen surveillance, rapid response and vaccination efforts

[EXTRACT] 3 February 2026, WASHINGTON, D.C. —
 During 2025, the Region of the Americas experienced a sharp increase of measles with a total of 14 891 confirmed measles cases, including 29 deaths, reported in 13 countries (Figure 1). This marks the highest annual case count since 2020 and a 32-fold increase compared with 2024 (Figure 2). Cases were reported in countries where measles had been previously low or absent, including Argentina (n=36), Belize (n=44), the Plurinational State of Bolivia (n=597), Brazil (n=38), Canada (n=5 436; including two deaths), Costa Rica (n=1), El Salvador (n=1), the United States of America (n=2 242; including three deaths), Guatemala (n=1), Mexico (n=6 428 cases; including 24 deaths), Paraguay (n=49), Peru (n=5), and Uruguay (n=13) (Figure 1). Despite intensified surveillance and vaccination efforts, the increase in cases throughout the Region led to the reestablishment of endemic measles transmission in Canada in October 2025 and by persistent outbreaks in the United States, Mexico and Bolivia.[...]