Vet Med postdoc studies impact of deforestation on wildlife viruses and human health in Cambodia

In a major advancement for wildlife health research, Dr. Charles C.Y. Xu, PhD, a postdoctoral scientist, has joined the University of Calgary's Faculty of Veterinary Medicine (UCVM) as a postdoctoral scholar for the next three years. 

Xu is conducting pioneering research on how land-use change in Cambodia, a biodiversity hotspot and country that has experienced high levels of deforestation in recent years, affects wildlife viral diversity and evolution. When forests are cleared for agricultural development, it causes significant disruptions to animal communities. Rodent populations, for instance, transition from stable, low-density forest species to those that are seasonally variable and typically found closer to human habitats. This shift can create pathways for pathogens, previously confined to the forest, to spread to humans and domestic animals.

Xu emphasizes the significance of exploring the impact of how land-use, and namely the rapid expansion of cities and towns taking over previous wildlife habitats, changes wildlife viruses at the genomic level. 

“Genomics enable us to ask deeper ecological and evolutionary questions beyond simply knowing whether pathogens are present or not," says Xu. "We can reconstruct viral genomes, identify specific genes, and observe the evolution of wildlife viruses in response to deforestation.”

Built on the foundational work of UCVM’s Dr. Mathieu Pruvot, PhD'14, DVM, and the Institut Pasteur du Cambodge, Xu’s research is a multi-faceted collaboration led by the Wildlife Conservation Society (WCS) Health Program including the Leibniz Institute for Zoo and Wildlife Research, and supported by a prestigious three-year fellowship from the U.S. National Science Foundation (NSF).

Above: Image A shows land-use change between 1989 and 2014 across Cambodia. Evergreen forest is in dark green; open or degraded forest in light green, urban or agriculture in tan; and water in blue. Image B shows a forest before deforestation, and four to six months after, at one sampling site.

Pruvot’s most recent work highlights the importance of understanding how deforestation influences zoonotic disease emergence, in the study titled, "Small Mammals at the Edge of Deforestation in Cambodia: Transient Community Dynamics and Potential Pathways to Pathogen Emergence."  

Pruvot underscores the critical nature of this research: “As society grapples with the intertwined challenges of land-use change, biodiversity loss and emerging infectious diseases, understanding these dynamics becomes crucial.”

Together, the researchers aim to map wildlife viral communities at different stages of deforestation using cutting-edge molecular and bioinformatic tools. This work will not only inform policy decisions, but also highlight the human health benefits of protecting nature. 

In addition to his research, Xu is committed to broadening the impact of his work through science communication and outreach. He is collaborating with the WCS Education Department at the Bronx Zoo to develop online educational modules targeted at grades 3-12, as well as local stakeholders in Cambodia. Xu is also engaging with UCalgary through potential collaborations, including co-instructing courses and working alongside PhD students.

"I am really excited about this work because, as COVID-19 recently reminded us, pandemic-prevention is one of the greatest challenges facing human civilization," says Xu. "The international nature of this project also reminds us that we need to collaborate across borders since viruses know not of them. We are all in the same boat, on one planet, with One Health."