The Southwest United States is facing a historic health crisis as federal officials confirm the region is experiencing the largest single measles outbreak since the disease was declared eliminated in the country in 2000.
According to internal details shared during a CDC-led meeting with state health officials, the outbreak has now surpassed earlier case counts from previous years, including the major 2019 outbreak that reached 1,249 cases nationwide. Unlike that outbreak, which was fueled by multiple international introductions, health experts say this one is spreading from a single source and is largely concentrated in Texas, Oklahoma, and New Mexico.
“This is the largest outbreak in the U.S. since measles elimination was declared in 2000,” said Dr. Dan Filardo, who heads the CDC’s measles response task force. He confirmed the agency is deploying additional personnel to Texas, the current epicenter of the crisis.
Texas at the Center of the Crisis
Texas health officials have reported at least 624 cases since late January. Among them are two young, unvaccinated girls who have died—marking the first measles-related fatalities in the United States in more than a decade. Of the total infections reported nationwide, 70 percent have occurred in children, with the median age of patients being just 8 years old.
Roughly 11 percent of all known U.S. cases have required hospitalization, most of those in Texas. The CDC says more than 800 cases have been officially documented, but the actual figure is likely higher due to reporting delays and ongoing case confirmations.
Low Vaccination Rates Fueling the Spread
Nearly all infections have occurred in people who were either unvaccinated or whose vaccination status remains unknown. The outbreak has disproportionately impacted Mennonite communities across the Southwest—groups known for lower vaccine uptake.
Religious gatherings, weddings, and large community events tied to the 500th anniversary of Mennonite origins are believed to be accelerating the spread. Dr. Filardo warned that more outbreaks could follow in other rural and Plains communities if transmission is not halted quickly.
International Links Widen the Threat
The situation is no longer confined to U.S. borders. Related outbreaks have erupted in Ontario, Canada, and Chihuahua State, Mexico—both areas with strong Mennonite populations. Canada has recorded nearly 1,000 cases since October, and Mexico has surpassed 400 infections, including one adult death.
Health officials say that gatherings bringing together individuals from different countries are increasing the risk of cross-border transmission, especially in regions where immunization rates are lower than average.
