The United States has reportedly lost its measles elimination status after health experts found the virus had spread continuously for at least 12 months. The decision ends a 26-year period in which the country was considered to have eliminated the disease.
The Pan American Health Organization (PAHO) made the determination after reviewing evidence from the Centers for Disease Control and Prevention, according to reporting by the Reuters news service, which cited a Wall Street Journal report. An independent expert commission advising PAHO’s director concluded that the United States no longer met the criteria, DW reported.
The review focused on whether one measles strain had circulated without interruption for 12 months or longer. Continuous transmission indicates local spread rather than cases brought into the country from elsewhere.
Cases have risen across the country
The CDC had recorded 5,182 confirmed measles cases this year as of Thursday, across 45 states, New York City and Washington, D.C. That is more than twice the 2,289 cases reported in 2025. Nearly all of this year’s cases have involved people who were unvaccinated or whose vaccination status was unknown, according to the source report.
Measles elimination does not mean a disease has disappeared permanently; the designation depends on stopping sustained transmission. To regain the status, a country must end transmission and remain free of outbreaks for at least 12 months.
PAHO had said it would review the measles elimination status of the United States and Mexico in November. The organization’s review notice outlined the planned assessment.
Reid Bentley