Reintroduction of measles in Chihuahua, Mexico, February–August 2025

Abstract

In February 2025, a measles virus circulating among Mennonites in western Texas, USA, was introduced into Cuauhtémoc, Chihuahua, Mexico. Since then and until August 8, 2025, 3,652 cases and 14 deaths have been confirmed in the state. In late April and early May, a vaccination campaign was implemented with nearly half a million doses, resulting in a gradual decline in the number of reported cases. The state has reported 93.4% of all cases nationwide. It has been observed that the majority of cases (86.8%) have no documented vaccination history, that the highest rates of reported incidence are in children aged 6-11 months, followed by those aged 0-6 months, and then among people aged 20-39. The fatality rate among indigenous peoples is almost 20 times that of the rest of the population.