U.S. measles elimination status may be lost

The Pan American Health Organization will meet April 13 to review whether the U.S. has lost its measles elimination designation after outbreaks that began in West Texas spread to multiple states and other countries.

It has been a year since a measles outbreak began in West Texas and international health officials are now reassessing the United States' measles-free designation. Public health experts say chains of cases have appeared in several states and the same virus strain has been identified in other North American countries. The formal question focuses on whether a single chain of measles transmission persisted uninterrupted for at least 12 months. Pan American Health Organization officials will review final data at an April 13 meeting to make the determination. Key facts: - The Centers for Disease Control and Prevention reported 2,144 confirmed measles cases across 44 states in 2025, the most since 1991. - The Texas outbreak that began in January 2025 was officially reported to have 762 cases and was linked to cases in other states and countries. - U.S. health officials say they do not currently have evidence that a single chain of transmission continued for a full year. - The Pan American Health Organization will meet on April 13 to decide whether the U.S. has lost its measles elimination status. Summary: The pending PAHO review will use available case data and sequencing to judge whether uninterrupted national transmission meets the definition for loss of elimination. The outcome will be a formal determination by international health authorities on April 13; the final decision is undetermined at this time.