Epidemiological Update Measles in the Americas Region - 2 May 2025

In 2025, between epidemiological week (EW) 1 and EW 16, in the Americas Region, 2,325 measles cases have been confirmed, including four deaths, in Argentina (n= 22), Belize (n= 7), the Plurinational State of Bolivia (n= 1), Brazil (n= 5), Canada (n= 1,069), Mexico (n= 421 cases, including one death), and the United States of America (n= 800, including three deaths) . This total represents an 11-fold increase compared to the 205 measles cases reported in the same period of 2024.

The distribution of confirmed measles cases in the Americas Region by epidemiological week shows an increase in cases as of EW 3 of 2025, with the maximum number of cases recorded in EW 14 related to outbreaks in vaccine hesitant communities settled in several countries of the region. According to the information available from confirmed cases, the age group with the highest proportion of cases corresponds to the 10-19-years-old group (24%), the 1–4-year-old group (22%) and the 20–29-year-old group (19%). Regarding the history of vaccination, 30% of the cases were not vaccinated and in 65% this information was unknown or absent.