The United States has lost its measles elimination status after 26 years, an independent expert commission reporting to the Pan American Health Organization has determined, following two years of falling vaccination rates and record case numbers.

Measles had been considered eliminated as a continually transmitting illness in the US since 2000. A source close to the process told CNN on Friday that the commission found the country no longer qualified. The decision was first reported by The Wall Street Journal.

How the determination is made

The commission treats an infection as endemic if infections caused by the same strain pass from person to person for at least a year within one country. Members examine the genetic code of viruses sampled from patients: every time a virus copies itself it makes small changes, so genome sequencing shows how closely infections are related and whether they belong to the same chains of transmission.

In August, scientists at Utah’s public health laboratory published a preprint showing the same strain had circulated in the state for more than a year, accounting for more than 95% of cases there and causing more than 600 cases between June 2025 and June 2026. Sustained outbreaks have also run in South Carolina, Pennsylvania, Wisconsin and New York.

It is not clear what data the commission relied on, but the Utah data alone would have been enough, Dr. Angela Rassmussen, a virologist at the University of Saskatchewan, told CNN.

The case numbers

More than 5,400 measles cases have been reported in the US this year — the highest since 1991. Most are linked to the 43 new outbreaks this year, though more than 1,000 are linked to outbreaks that began last year. Nearly all cases were in people who had not received the MMR vaccine or whose vaccination status is unknown. About one in nine reported cases resulted in hospitalisation, according to the CDC, and at least 10 people have died.

Two doses of the measles-mumps-rubella vaccine cut an exposed person’s chance of falling ill by 97%.

“Measles elimination is a vital sign for our public health system. It shows cracks in our foundation.”

— Dr. Demetre Daskalakis, former director of the CDC’s National Center for Immunization and Respiratory Diseases

The regional picture

The Americas were the first region in the world to eliminate endemic measles transmission, in 2016. Canada lost its status last November, and Mexico, Guatemala, Peru and Bolivia were also under review, Al Jazeera reported as the commission began its annual conference in Washington on Tuesday.

PAHO recorded 57,666 confirmed measles cases across 17 countries and territories in the Americas between January and October 2026.

Al Jazeera’s explainer noted that reported cases or deaths alone do not cost a country its status — a limited outbreak seeded by an infected traveller would not — and that the commission also weighs vaccination coverage, surveillance and the speed of outbreak response. To regain elimination status, a country must stop transmission and stay outbreak-free for at least 12 months.

A caution on the announcement

The commission makes recommendations to PAHO Director Jarbas Barbosa, who makes the final determination. Al Jazeera reported on Wednesday that the official announcement was expected early the following week. CNN’s Friday report rests on a source close to the process rather than on a published PAHO statement, so the formal announcement had not been made at the time of writing.

Hiru News carried the decision in Sinhala on Saturday morning, attributing it to CNN; its case, death and Utah figures match CNN’s.

Not reported

No filing says what data the commission actually relied on, when the US might regain elimination status, or what the decision changes in practice — Al Jazeera notes the loss triggers no immediate consequences. None of the sources reports any implication for Sri Lanka, for travellers between the two countries, or for local measles surveillance, and this desk has not established whether there is one.