Canada is no longer considered measles-free, according to international health experts who reported on Monday that the country is grappling with ongoing outbreaks. This alarming development is attributed to a decline in childhood vaccination rates coupled with the rapid spread of the highly contagious virus across both North and South America.
The loss of Canada’s measles elimination status comes more than a year after the virus began to circulate within the population. As of now, Canada has reported a staggering 5,138 measles cases in 2023, alongside two tragic deaths. Both fatalities involved infants who were exposed to the measles virus in utero and were born prematurely.
The designation of measles elimination is symbolic but represents significant progress in the battle against this infectious disease. It is awarded to countries that successfully halt the continuous spread of the virus within their communities, although isolated cases may still arise due to international travel. Measles typically initiates with a high fever, followed by a distinctive rash that starts on the face and neck. While most individuals recover, measles remains one of the leading causes of death among young children, as highlighted by the World Health Organization.
Serious complications associated with measles, such as blindness and encephalitis, are notably more prevalent among young children and adults over the age of 30. The most effective prevention method is through the measles vaccine, which is administered routinely and safely to children worldwide.
“It’s a deeply disheartening development. It’s a deeply worrisome development. And, frankly, it’s an embarrassing development,” stated Jennifer Nuzzo, an infectious disease expert from Brown University. She emphasized that no country with the resources available to Canada, or other nations in North America, should lose their measles elimination status.
Canada achieved measles elimination in 1998, followed by the United States in 2000. Following successful vaccination campaigns, the Americas were declared the first region in the world to be free of measles in 2016. Health officials estimate that the measles vaccine has prevented approximately 6.2 million deaths in the Americas between 2000 and 2023. However, vaccination rates have since dropped below the 95% coverage required to effectively halt outbreaks.
Major outbreaks in Venezuela and Brazil in 2018 and 2019 led to the region losing its elimination status, which was only temporarily regained in 2024 before losing it again due to Canada’s recent challenges. Experts from the Pan American Health Organization determined that the virus had spread continuously in Canada for over a year, prompting their assessment.
Dr. Jarbas Barbosa, director of the Pan American Health Organization, acknowledged the difficulty in stopping measles from circulating within local communities. “As a region, we have eliminated measles twice,” he stated. “We can do it a third time.” In response, Canadian health officials are collaborating with government and community partners to enhance vaccination coverage, share data, and provide evidence-based guidance.
Measles is recognized as one of the most contagious viruses known to medicine, with an infected individual capable of transmitting the virus to up to 90% of unprotected individuals they come into close contact with. Health experts assert that the best prevention strategy remains the vaccine, which offers 97% protection after two doses. Barbosa's organization has confirmed nearly 12,600 cases across 10 countries this year, marking a 30-fold increase from 2024. Most of the cases are concentrated in Canada, the U.S., and Mexico, but outbreaks are also occurring in Bolivia, Brazil, Paraguay, and Belize.
The United States, which achieved measles elimination in 2000, faces a similar risk of losing its status. Although a large outbreak that resulted in three deaths and nearly 900 infections across Texas, New Mexico, and Oklahoma earlier this year has concluded, new outbreaks are emerging. Current cases include 34 in South Carolina and over 150 linked to an outbreak on the Arizona-Utah border.
To lose its elimination status, the U.S. must demonstrate a continuous chain of measles spread for one year. International health officials have advised the U.S. to enhance case investigation protocols, as closing data gaps is crucial to prevent the virus from re-establishing itself, according to Dr. Daniel Salas, who directs immunization efforts at the Pan American Health Organization.
As of now, the U.S. Centers for Disease Control and Prevention (CDC) has confirmed 1,681 cases and 44 outbreaks in 2023, marking the worst year for measles in the U.S. in over three decades. Only nine states have not reported cases, highlighting the widespread nature of the current outbreaks.
In Mexico, a significant outbreak is ongoing in Chihuahua, with health officials confirming 4,430 cases and 21 deaths as of last week. Mexican and U.S. authorities have noted that the genetic strains of measles circulating in Canada match those in the Texas and Chihuahua outbreaks, many of which have affected specific Mennonite Christian communities linked historically between Canada and Mexico.
While Mennonite churches do not formally discourage vaccination, many conservative communities have historically exhibited low vaccination rates and a distrust of governmental health initiatives. Nuzzo emphasized the interconnectedness of these outbreaks, attributing them not only to travel but also to the spread of anti-vaccine misinformation. “It’s not a religious prohibition in most of these cases,” she clarified. “It is just people being, perhaps, distrustful of authorities, but also preyed upon by these anti-vaccine influencers who profit off of the fears that some people may have.”
As health officials continue to work towards improving vaccination rates and combating misinformation, the situation remains critical. Addressing the challenges of measles outbreaks is essential for protecting public health across Canada, the United States, and the broader region.