Measles Cases Surge 32-Fold in the Americas, WHO Issues Alert
The number of measles cases across the Americas has increased dramatically, prompting an alert from the World Health Organization (WHO). The surge in infections underscores the critical importance of vaccination efforts to prevent the spread of this highly contagious disease.
In 2025, a total of 14,891 measles cases were identified throughout the continent, a nearly 32-fold increase compared to the 446 cases reported in 2024. This trend has continued into 2026, with preliminary data from January indicating 1,031 cases – almost 45 times the number recorded during the same period in 2025 (23 cases). There have been no deaths confirmed in 2026, but 29 fatalities were reported in 2025.
The majority of these cases are concentrated in North America, with Mexico (6,428), Canada (5,436), and the United States (2,242) accounting for approximately 95% of all reported cases in 2025. In January 2026, these three nations represented 92% of the cases reported across the continent.
According to the Pan American Health Organization (PAHO), the regional office of the WHO, the increase in measles cases “constitutes a warning sign that requires immediate and coordinated action by Member States.” PAHO had previously removed the region’s certification as being free of measles transmission in November.
A significant proportion of those contracting the disease are unvaccinated. In the United States, 93% of individuals who developed measles were not vaccinated or had an unknown vaccination history. Similar trends were observed in Mexico (91.2%) and Canada (89%).
PAHO is urging countries to prioritize strengthening vaccination activities to combat the outbreak. While Brazil has reported 38 cases and is currently considered free of the disease, the organization notes the country faces a risk of reintroduction due to travel between nations. The findings could guide future vaccination strategies and public health interventions across the region.
The alert from PAHO details that the vast majority of cases are occurring among individuals without a history of vaccination against the disease. This underscores the importance of maintaining high vaccination coverage rates to protect communities from outbreaks.
