A public health approach is required when researching zoonotic disease risks

A public health approach is required when researching zoonotic disease risks

A new evidence brief based on a Juno Evidence Alliance study conducted in collaboration with CABI's One Health Hub has highlighted the need for a One Health approach to researching the risks of zoonotic diseases around the world.

The study, an evidence synthesis conducted by the Juno Evidence Alliance with Newcastle University and funded by UK International Development, found no published research on zoonotic disease risks associated with agricultural and food systems for 46% of low- and middle-income countries (LMICs), which may indicate an unequal distribution of research resources.

It adds that several key areas related to the emergence of zoonotic diseases remain poorly understood in published research. This includes evidence from specific food system contexts using One Health perspectives, wildlife hosts, and how exposure to wildlife may influence abundance in humans and domesticated animals.

Zoonoses pose a significant threat to human health and well-being, with approximately 60% of known human infectious diseases and 75% of emerging infections originating from animals.

Decision makers lack evidence-based linkages

Dr. Marie McIntyre, Fellow in Translational Food Safety at Newcastle University and lead subject matter expert on the study, said: "Zoonoses are responsible for 2.5 billion cases of illness and 2.7 million human deaths worldwide each year. Agricultural and food systems play an essential role in the emergence of zoonotic diseases."

"Factors such as land use change, intensification of livestock production and wildlife trade all contribute to disease risks. Meanwhile, the impacts of climate change could pose further challenges."

“However, despite the increasing recognition of these connections, our research shows that decision-makers lack evidence-based connections linking certain practices to the emergence of zoonotic diseases.”

The research presents the current evidence base on factors influencing the occurrence of zoonotic diseases in agricultural and food systems in LMICs.

The researchers conducted a systematic mapping and search of five bibliographic databases and 17 organizational websites. In total, 7839 of the 49,038 unique publications were identified as potentially relevant using manual review and machine learning. A 14% random sample (1034 publications) was reviewed in full text and 424 of these were included in the map.

The four most frequently examined categories of factors were exposure to potential hosts or vector species, particularly livestock (occurring in 53% of publications), social and economic factors (47%), physical and environmental factors including land use, climate and weather (46%), and practices in domesticated animals (38%).

Zoonotic diseases associated with agricultural and food systems pose a significant risk

Zoonotic diseases associated with agricultural and food systems pose a significant risk to global health, but the factors driving their increase are not fully understood.

While certain areas are well studied, knowledge gaps exist in other areas, such as specific food system contexts, geographic regions, and One Health perspectives.

By engaging in systems-based research and policies to address these gaps, policymakers can prioritize resources, improve preparedness, and reduce the risk of disease spreading from animals to humans.”

Dr. Hazel Cooley, co-lead author of the study

Several recommendations

The study presents several recommendations for researchers, policy makers and decision-makers.

The focus is on understanding the transmission processes along the food chain. This includes food processing, distribution and consumption systems. Research that focuses on an integrated, systems-based approach is critical, the researchers say. It describes in detail how changes in agriculture, land use and food demand interact across agricultural and food systems.

Additional recommendations include supporting international collaboration, particularly with LMICs, to address country-specific research gaps and improve understanding of zoonotic risks.

Creating a dialogue around One Health research

The results of the Zoonoses Systematic Map will inform a One Health research roadmap published by CABI's One Health Hub.

FAO's One Health Knowledge Nexus (OHKN) will host a webinar to discuss these findings and their implications for global One Health research. The event takes place as part of the OHKN Community of Practice on the topic “Drivers of emerging plant and animal pests and diseases, including zoonotic spillovers”.

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