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When researchers from Dalhousie University began studying mpox cases in central Africa, they expected to see patterns similar to those observed in recent global outbreaks. Instead, they found something different, and potentially important for how the disease is understood worldwide.

A new study published in The Lancet Infectious Diseases highlights an increased number of mpox cases among children and adolescents during a large outbreak in the Democratic Republic of the Congo. The findings are helping researchers better understand how the virus behaves in different populations, and how it may be changing.

A shift in who is affected

Mpox, a viral infection that spreads through close contact with an infected person, has often been associated with transmission via sexual activity among adults. It typically causes fever, swollen lymph nodes, and a painful rash or skin lesions. 

But the Dalhousie-led research suggests that pattern is evolving.

“Our group identified large numbers of children and adolescents with mpox disease in the eastern region of Democratic Republic of the Congo,” says Dr. Gustavo Sganzerla Martinez, postdoctoral fellow and mpox research team member in Dalhousie’s Department of Microbiology and Immunology. “This marks a major shift in the target population from mostly adults to children and adolescents.” 

Dr. Martinez works in the Laboratory of Emerging Infectious Diseases at Dalhousie, led by Dr. David Kelvin, Canada Research Chair in Translational Vaccinology and Inflammation. It’s here that they conduct internationally based research studies on ancient infectious diseases, infectious emerging diseases, and cancer development. 

New clues in transmission

The study also points to possible differences in how the virus spreads among children and that there may be other routes of transmission in younger populations.

“The shift of mpox infections from adults to children suggests new modes of transmission in children,” says Dr. Sganzerla Martinez. “We can now attribute the transmission in children to something else besides sexual activity.” 

Researchers identified the virus in the throat (oropharynx) of some participants, including children, in some cases even before skin lesions appeared, which is often an early sign. This raises the possibility that respiratory particles through coughing, as well as crowded household conditions, could contribute to transmission via droplets. 

“What are the routes of transmission in children?” asks Dr. Sganzerla Martinez. “We are intensely trying to find the answer to this question.” 

A global lens on infectious disease

The study underscores the importance of examining infectious diseases in diverse settings and populations. While the research focuses on an outbreak in central Africa, its implications extend far beyond the region.

As international travel increases, infectious diseases can move quickly across borders, making it essential to understand how they spread and evolve.

“While we were working on this new mpox virus, the World Health Organization declared a Public Health Emergency of International Concern (PHEIC) and travel-related cases of the new virus were documented worldwide, including North America with cases in Canada,” says Dr. Sganzerla Martinez. 

The PHEIC has since been lifted, but the study's findings have important implications for public health, including in Canada.

“Given the possibility of imported cases, it is important that public health officials be aware of possible mpox cases in both adults and children travelers and take appropriate measures to prevent transmission and stop outbreaks before they start,” says Dr. Sganzerla Martinez.

At the same time, it’s important to note that the findings reflect a specific outbreak context, and do not indicate a heightened risk to the general public in Canada. Rather, the work helps public health experts stay informed and prepared should cases arise.

By improving our understanding of how mpox presents and spreads in children, the research can help inform earlier detection, more effective prevention measures, and stronger responses to future outbreaks.

Looking ahead

This kind of work depends on strong collaboration across institutions and borders. The study is supported by a network of national and international funders, including the Canadian Institutes of Health Research, the Canadian Foundation for Innovation, Research Nova Scotia, the Dalhousie Medical Foundation, Moderna, the Li Ka Shing Foundation, and the European & Developing Countries Clinical Trials Partnership—reflecting the global effort required to study and respond to emerging infectious diseases.

As researchers continue to study the evolving mpox virus, one thing is clear: understanding how it behaves across different populations is essential to staying ahead of it.

For Dalhousie scientists, that means continuing to ask critical questions and working across global contexts to find answers that can protect communities everywhere.