Ontario measles surge prompts CMAJ to warn of cross-border data gaps and rising misinformation
More measles cases have been reported in Ontario alone than across the entire US since February, according to the Canadian Medical Association Journal (CMAJ), which warns that Canada’s ability to manage communicable diseases is being undermined by dismantled US health infrastructure.
As per the CMAJ editorial authored by medical editor Shannon Charlebois and University of Toronto public health physician Jasmine Pawa, the Trump administration’s health budget cuts pose “immediate and long-term risks to the health of neighboring countries.”
They reported that the US has nearly halved the budget of the Centers for Disease Control and Prevention (CDC), reduced the National Institutes of Health (NIH) budget by 40 percent, and is planning mass retrenchments at the Department of Health and Human Services.
Programs monitoring pandemic threats and tracking the spread of diseases such as HIV and avian influenza have been “decimated,” according to the CMAJ, limiting long-term trend estimation and response planning.
These actions have also weakened the United States’ ability to share essential data with global counterparts, including Canada.
Charlebois and Pawa wrote that “cuts have included actions to paralyze evidence-based science, such as firing of personnel with the skills to develop tests for rapidly evolving diseases.”
They warned that Canadian preclinical trials, such as those treating Ebola, could be affected due to reliance on antibodies developed in US NIH-funded labs.
The editorial further pointed to a surge in infectious disease rates within Canada.
According to the CMAJ, syphilis and HIV rates have risen sharply, vertical transmission of infections has increased, and livestock across the country are being culled due to avian influenza.
From 1993 to 2004, Canada reported only 1 to 4 congenital syphilis cases per year, but from 2018 to 2023, the figure rose to over 50 annually.
The CMAJ also flagged growing concerns around drug-resistant tuberculosis, hepatitis B, and imported Oropouche virus.
The authors stressed that outbreaks tend to disproportionately affect marginalised populations, adding complexity to Canada’s public health response.
To address these risks, they recommend strengthening health surveillance systems, including improved national interoperability and data exchange across medical, hospital, and health records.
As per the CMAJ, this can be guided by the Pan-Canadian Health Data Content Framework and other collaborative platforms.
They urged collection of equity stratifiers — demographic, social, economic, and geographic data — based on the Canadian Institute of Health Information’s inequality toolkit standards.
Charlebois and Pawa also recommend tracking vaccine coverage and antimicrobial resistance rates more precisely and aligning with the World Health Organization’s International Health Regulations.
Community collaboration to co-design responses to structural health determinants was also cited as crucial.
The CMAJ editorial underscored another escalating threat: misinformation.
They stated that “the Trump administration’s appointment to positions of authority of individuals who seed misinformation and publicly discredit national health institutions adds to the effects of existing misinformation.”
Robert F. Kennedy Jr., US Secretary of Health and Human Services, was highlighted for his history of promoting vaccine conspiracies.
The editorial warned of a “cross-border bleed” of misinformation and attitudes into Canada, amplified by exposure to biased US media.
As reported by the Canadian Medical Association’s 2025 Health and Media Tracking Survey, 43 percent of Canadians were highly susceptible to misinformation in 2023, and 35 percent were moderately susceptible.
To address this, Charlebois and Pawa support increased investment in plain-language public content through knowledge translators in Canadian media.
The CMAJ committed to continuing its role in curating health information to support the country’s systems in managing what it describes as an “acute-on-chronic burden of infectious disease.”
