Six countries in the Americas had reported 2,318 confirmed measles cases and three related deaths by April 18, 2025. The number of reported cases during this period represents an 11-fold increase compared to 2024 statistics. The highest number of infections has occurred among unvaccinated individuals or those with unknown vaccination status, particularly within the 1 to 29-year-old age group. Most transmissions have been linked to imported cases or travel-related exposure, underscoring the disease’s potential for global spread.
Measles is highly contagious, spreading through respiratory secretions, airborne particles, and contact with contaminated surfaces. It can lead to serious complications, including pneumonia and encephalitis (brain inflammation), which can result in blindness or death. Although two doses of the MMR (measles, rubella) vaccine provide effective protection, global vaccine coverage remains insufficient. In 2023 alone, 22 million children were left unvaccinated against measles, increasing the vulnerability of multiple population groups.
The current outbreak has revealed significant case counts in several countries. Canada has reported the highest number, with 1,069 confirmed cases, followed by the United States (800), Mexico (421), Argentina (21), Brazil (5), and Belize (2). In Canada, most cases have stemmed from under-vaccinated communities, with a large outbreak traced to international travelers in 2024.
