Between the start of January and October 31, 2026, the Region of the Americas recorded 57,666 confirmed cases of measles across 17 countries and territories, marking a 4.7-fold increase compared to the same period in 2025, MesVaccins reported.
Guatemala, Mexico, the United States, Peru, and Canada accounted for 99.5 percent of those confirmed cases. Across the region, 81 deaths were reported during this timeframe, with 53 in Guatemala, 23 in Mexico, three in the United States, one in Peru, and one in Bolivia.
During epidemiological weeks 41 and 42 of 2026, the region registered 547 new confirmed measles cases in six countries and territories. That figure represents a 38 percent decrease compared to the preceding two-week period.
In the United States, 5,182 confirmed measles cases were logged by November 5, 2026. Pennsylvania, South Carolina, Utah, and Wisconsin reported the highest totals, while 47 jurisdictions nationwide felt the impact.
Roughly 96 percent of the U.S. cases occurred in individuals who were unvaccinated or whose vaccination status remained unknown. The effective reproduction number across the country settled at 1.01, pointing toward sustained transmission.
Guatemala carried the heaviest burden with 34,748 cumulative cases through epidemiological week 43. While national numbers declined from a peak earlier in the year, young adults aged 15 to 39 made up 62 percent of the confirmed infections.
Mexico recorded 13,761 cumulative cases, concentrated heavily within the states of Jalisco, Mexico City, and Chiapas. Meanwhile, Peru logged 2,862 cases, with transmission clustered primarily in the southern departments of Puno and Arequipa.
Canada marked 1,126 cumulative cases, recording its latest imported case during epidemiological week 41 following a multi-state outbreak that began in New Brunswick. Bolivia and Brazil reported active transmission in localized pockets, while smaller nations across Central America logged only sporadic cases tied to recent travel.
