Canada loses its measles elimination status. Will the U.S. be next?
Canada has lost its measles elimination status, the country’s Public Health Agency announced Monday, due to its failure to control an ongoing outbreak for at least a year.
A World Health Organization group “reviewed recent epidemiological and laboratory data confirming sustained transmission of the same strain of measles virus in Canada for a period of more than a year,” the Public Health Agency of Canada said in a statement.
Canada eliminated measles in 1998, two years before the United States
As of Monday, the country’s health authorities had recorded 5,138 cases of measles since October 2024. The epidemic began in New Brunswick, a province located on the east coast of the country. Two babies, infected in utero, were born prematurely and died.
The United States is also on the verge of losing its measles elimination status, as an outbreak that emerged in January continues to spread across the country.
The outbreak began in West Texas and spread to New Mexico. At least 862 people – mostly in Texas – have been infected. Three people died. Two were little girls who lived in the epicenter of the outbreak, in Gaines County, Texas.
Although cases declined in West Texas, the virus continued to spread. Utah and Arizona are experiencing an outbreak concentrated in a close-knit community that straddles the state line.
Last week, 1,681 cases of measles were confirmed in the United States in 2025, according to the Centers for Disease Control and Prevention, the highest number in more than 30 years.
Who determines a country’s measles elimination status?
The Pan American Health Organization (PAHO), part of the WHO, determines whether a country in North, South, or Central America has maintained or lost its elimination status.
In 2019, PAHO created a group of independent experts, called the Regional Verification Commission, to conduct an annual review of how well countries are able to control the spread of measles.
The group met last week in Mexico City to analyze the latest measles data submitted by countries with active outbreaks through October.
There are many criteria for losing official measles elimination status, including declining vaccination rates. The most important factor is continued transmission of the same strain of the virus for a full year.
Canadian health authorities will now need to develop a plan to get back on track, including improving vaccination rates and “enabling better overall surveillance efforts,” the agency wrote.
Measles is the most contagious virus known on the planet. The virus can linger in the air for up to two hours after an infected person leaves the room. Anyone in this room who has not been vaccinated against measles will likely get sick.
