17 JUNE 2026, WASHINGTON, D.C. — More than 184 000 suspected measles/rubella cases have been reported worldwide in 2026, reflecting widespread transmission across all WHO regions. In the Americas Region, confirmed cases have reached 20 521 by EW 20 -- with 25 deaths -- representing a four-fold increase from the number reported in the same period in 2025. Against this backdrop, mass gatherings and cross-border travel act as amplifiers of transmission, particularly in populations with suboptimal vaccination coverage. Strengthening active case-finding, maintaining high immunity levels, and ensuring pre-travel vaccination are essential to reducing the risk of measles importation and onward spread.
These trends are further characterized by the global distribution and confirmation of cases across regions. Across the six WHO regions, 100 239 (54.3%) measles cases were confirmed by laboratory testing, clinical or epidemiological criteria. The WHO South-East Asia Region accounted for 29% of reported cases, followed by the WHO Eastern Mediterranean Region with 21%, while the WHO African Region and the Americas each accounted for 19%.
In the Region of the Americas, cases were reported by 16 countries and one territory. Altogether, the 5 123 cases reported in 2025 and 20 521 confirmed cases in 2026 represent the highest regional measles activity since 2019, when the Americas recorded the highest number of confirmed cases in the previous 22 years (n = 23 269) (Figure 2). By EW 20 of 2026, the largest numbers of confirmed cases were reported by Mexico (n=10 920, including 13 deaths), Guatemala (n=6209, including 12 deaths), This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 IGO License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited. No modifications or commercial use of this article are permitted. In any reproduction of this article there should not be any suggestion that PAHO or this article endorse any specific organization or products. The use of the PAHO logo is not permitted. This notice should be preserved along with the article’s original URL. Open access logo and text by PLoS, under the Creative Commons Attribution-Share Alike 3.0 Unported license. the United States of America (n=1 952), Canada (n=1 018), Peru (n=301), and Bolivia (n=70) (Figure 3).
Available data on confirmed cases in 2026 in the Americas show a higher proportion among people aged 20–29 (24%), followed by those aged 10–19 (20%) and 30–39 (16%). However, the incidence was highest among children under one year of age (9.7 cases per 100 000 population), followed by children aged 1–4 years (4.1 per 100 000) and 5–9 years (3.0 per 100 000). Forty-five percent of cases were unvaccinated, and for 45%, vaccination status was unknown or unavailable. The source of infection was identified as unknown in 36% of cases, related to imported cases in 23%, endemic in 6%, and imported in 2%.