As measles cases continue to rise in the United States, neighboring countries Canada and Mexico are also grappling with significant outbreaks, each reporting at least one death linked to the virus.
According to CNN, in Ontario, Canada, officials confirmed the death of an infant who was born prematurely with a measles infection.
On Thursday, the province’s chief medical officer of health, Dr. Kieran Moore, explained the circumstances, “The infant contracted the virus before birth from their mother, who had not received the measles, mumps and rubella (MMR) vaccine,” he said in a statement. “While measles may have been a contributing factor in both the premature birth and death, the infant also faced other serious medical complications unrelated to the virus.”
Mexico has reported four measles-related fatalities so far in 2025. In the United States, three deaths have occurred, two children in Texas and one adult in New Mexico, all of whom were unvaccinated.
This year’s outbreaks pose particular dangers to pregnant individuals and infants, as health experts stress. Both Canada and Mexico are facing their largest measles surges in decades.
The World Health Organization recently stated that the “overall risk of measles in the Americas Region is considered high.”
According to the agency, low vaccination coverage is a major factor driving the current wave of infections.
By late May, Mexico had logged at least 1,520 measles cases, based on data from the Pan American Health Organization.
Canada, which achieved measles elimination in 1998, is also seeing an alarming spike.
Federal data updated Monday show at least 2,755 cases reported this year alone, more than the cumulative total for the previous 27 years, with the majority concentrated in Ontario.
Meanwhile, the United States has documented at least 1,168 measles cases in, according to federal numbers released Friday.
Nearly 80% of those are connected to an outbreak that began in West Texas and has since extended into New Mexico, Oklahoma, and potentially Canada.
This marks the second highest annual case count in the U.S. since it declared measles eliminated in 2000.
Health authorities have traced a significant portion of the outbreaks across all three countries to Mennonite communities, which tend to have lower vaccination rates and limited interaction with conventional healthcare systems.
However, PAHO experts have so far stopped short of confirming a direct epidemiological connection between outbreaks in Canada, Mexico, and the U.S.
During a recent presentation, Dr. Alvaro Whittembury, regional adviser for PAHO’s Comprehensive Immunization Special Program, noted, “The outbreak [in Mexico] started in Chihuahua, at the heart of Mennonite communities, who were very close to Texas through the border, but they’re also close to other Mennonite communities in Canada.”
He emphasized, however, that “It’s important to show that although at first the outbreak starts in Mennonite communities … the vast majority of cases are outside of these communities, and they are sustained in the general population.”
Limited genetic sequencing of confirmed measles cases has further complicated efforts to establish direct links between outbreaks in different countries.
Experts from PAHO confirmed that not enough identical viral sequences have been found to definitively connect the cases.
As measles continues to spread, airports and tourist areas have emerged as high-risk exposure zones.
Travel advisories have been issued to help mitigate transmission. In April, Mexico cautioned its citizens about travel to the U.S. and Canada due to rising measles rates. Similarly, the U.S. Centers for Disease Control and Prevention urged international travelers to ensure they’ve received two doses of the MMR vaccine.
Dr. Moore reinforced this advice in his statement, “Anyone who is unvaccinated is at risk and I urge everyone, but especially those who may become pregnant, to ensure they have received two doses of the MMR vaccine, which will protect both a parent and baby.”
He added, “This vaccine has been safely used for over 50 years and is highly effective. Two doses provide nearly 100 per cent protection.”