Worldwide biosurveillance network needed to protect from diseases from unchecked wildlife trade
The severity of COVID-19 highlights the need for widespread pathogen screening and monitoring to better understand, predict and contain outbreaks in wildlife and humans. A group of eight researchers from San Diego Zoo Global in California, US, recommend a “decentralised” disease surveillance system which builds in-country capacity for addressing such challenges – the network would take a more fundamentally proactive approach to wildlife screening for pathogens and more thoroughly evaluates their spillover risk (of spreading from wildlife to humans or vice versa).
“The COVID-19 crisis has shown that the international wildlife trade is a global system in need of greater oversight,” said Elizabeth Oneita Davis, a conservation social scientist in Community Engagement at San Diego Zoo Global.
Davis added that ill-conceived measures such as ‘blanket bans’ could affect millions of people and drive wildlife trade activities deeper underground. This would further impede efforts to understand and reduce demand for wildlife. The scientists advise that surveillance focal points should include all wildlife markets and farms, as well as free-ranging populations of “high-risk” wildlife.
Genomic technologies, which have transformed radically since previous infectious disease outbreaks such as the H1N1 outbreak of 2009, can also supplement the surveillance system. Mrinalini Erkenswick Watsa, conservation geneticist on San Diego Zoo Global’s Population Sustainability team, explained, “Sequencing the genome of a virus is now feasible on miniature sequencers, directly at the point of sample collection.
“Today, we can more directly and powerfully survey wildlife health, identify areas of high spillover potential and contribute to minimising those behaviors, to keep human and wildlife populations safe,” Watsa said. This references the creation of a pathogen database to provide early warnings of spillover potential, and assist in containment and development of therapeutic treatments.
The scientists note that beyond endangering human health, emerging infectious diseases can imperil wildlife populations that have not evolved resistance to unfamiliar pathogens. A centralised location for deposition, analysis and reporting would therefore add even more value to conservation, and could serve as an open-access resource.
Additionally, the scientists call for an internationally recognised standard for wildlife trade, as little monitoring takes place in wildlife markets like the one believed to be the original vector of the SARS-CoV-2 virus.
“Decentralised pathogen screening in wildlife lends itself not only to early detection of pathogen spillover into humans, but helps conservation veterinarians and disease experts understand the natural host-pathogen relationship, allowing us to better conserve wildlife populations and save species,” said Dr. Caroline Moore, Steel Endowed Pathology Fellow and veterinary toxicologist on San Diego Zoo Global’s Disease Investigations team.
The decentralised system echoes the collaborative, holistic disease mitigation strategy of the One Health approach, used by the US Centers for Disease Control and Prevention: The One Health approach seeks to decrease the threat of disease through the conservation of nature and ecosystem function, while the proposed disease surveillance model will enable relevant authorities to track future changes in viruses and ecosystem health that are related to both human and wildlife populations.
