The Pan American Health Organization (PAHO) has issued a fresh warning as measles cases continue to rise sharply across the Americas, urging countries to step up disease monitoring and vaccination efforts. The alert comes amid a growing regional outbreak that has pushed infections well beyond levels seen in recent years.
According to PAHO, measles infections have climbed steadily since 2025, outpacing figures recorded over the previous five years—a worrying trend that shows no sign of slowing. In just the first three weeks of 2026, health authorities confirmed 1,031 new cases across seven countries. Mexico and the United States reported the highest numbers, marking a dramatic 43-fold jump compared with the 23 cases recorded during the same period last year.
The resurgence has already had serious consequences. In November, Canada lost its measles elimination status for the first time in nearly 30 years after failing to contain a prolonged outbreak. This setback also stripped the entire Americas region of its elimination status. Meanwhile, a fast-expanding outbreak in South Carolina has led to 876 confirmed cases, with officials cautioning that transmission could continue for weeks or even months due to lagging vaccine coverage.
In response, PAHO is pressing governments to act decisively. The agency is calling on member states to reinforce epidemiological surveillance systems, expand laboratory testing, and close immunity gaps through stronger vaccination campaigns. Rapid identification and response to suspected measles cases, PAHO says, will be critical to preventing further spread.
Data from the outbreak highlights the scale of the challenge. Among cases where vaccination status was known, 78% involved unvaccinated individuals, while another 11% had an unknown vaccination history. These figures, PAHO stressed, point directly to weaknesses in routine immunization programs as a key driver of the current surge.
As PAHO urges stronger disease surveillance as measles cases continue to climb across the Americas, health officials across the region face mounting pressure to restore vaccination coverage and contain outbreaks before they escalate further.
