Study Highlights Critical gaps in Understanding Zoonotic Disease origins
A new systematic map reveals that zoonotic diseases – those transmissible from animals to humans – cause an estimated 2.5 billion cases of illness and 2.7 million deaths globally each year, with agrifood systems playing a meaningful role in their emergence. However, despite this substantial impact, decision-makers currently lack sufficient evidence linking specific agricultural practices to the rise of these diseases.
The research, led by a safety expert at Newcastle University and dr. Hazel Cooley,co-lead author of the study,systematically reviewed nearly 50,000 publications,ultimately analyzing 424 relevant studies focusing on factors influencing zoonotic disease occurrence in low- and middle-income countries (LMICs). The review process involved both manual screening and machine learning techniques.
The study identified four key areas of investigation: exposure to potential hosts (particularly livestock, featured in 53% of publications), social and economic factors (47%), physical and environmental factors like land use, climate, and weather (46%), and domesticated animal practices (38%).
While research exists in these areas, the authors emphasize significant knowledge gaps remain, particularly concerning specific food system contexts, geographic regions, and the request of a “One Health” approach - recognizing the interconnectedness of human, animal, and environmental health.
“zoonotic diseases linked to agrifood systems represent a significant risk to global health, but the factors behind their rise are not fully understood,” stated dr. cooley. “By advocating for systems-based research and policies to address these gaps, decision-makers can prioritize resources, improve preparedness, and reduce the risk of diseases spreading from animals to humans.”
The researchers recommend a greater emphasis on understanding disease transmission throughout the entire food chain, including processing, distribution, and consumption. They also advocate for integrated, systems-based research to analyze the interplay between farming practices, land use changes, and food demand. Furthermore, the study stresses the importance of international collaboration, particularly with LMICs, to address country-specific research needs and enhance understanding of zoonotic risks.
The findings contribute to a One Health research roadmap developed by CABI’s One Health Hub, and will be discussed further in a webinar hosted by the FAO’s One Health knowledge nexus (OHKN) as part of their Community of Practice on emerging pests and diseases, including zoonotic spillover.
The research was published in Juno Reports (Cooley, H., et al. (2025) What are the factors behind emerging zoonotic diseases associated with agrifood systems? A systematic map. Juno Reports. DOI: 10.1079/junoreports.2025.0002).
