Zoonoses are infectious diseases that can be transmitted from animals to humans. Shockingly, they are responsible for a disproportionately large number of infectious diseases that have become widespread over the last 50 years. As the most recent zoonotic disease to emerge, COVID-19 has forced us to examine zoonoses closer, and in turn the root causes of zoonotic disease emergence.
The commercial wildlife trade plays an important role in the emergence and perpetuation of zoonoses. Wildlife markets see cages of wild animals, both dead and alive, stacked alongside dog and cat meat and domestic farm animals, creating a hotbed for disease. Farming of wildlife is growing on an industrial scale, with farms dedicated to sourcing bear bile and tiger bone for traditional medicines. Whether it be for consumption, to wear, to play with, or to own, human greed is fuelling the international trade of wild animals, and when the time comes, it will be human greed to blame when the next pandemic arises.
The scale of the international wildlife trade can be difficult to quantify due to its varied states of existence. An informal trade within a village, a market frequented by locals and tourists alike, all the way to fully established international trade routes – these must all be considered when estimating the scale of the wildlife trade industry. And with every documented case, we must also consider the poorly and undocumented cases of illegal wildlife trade that are rife throughout the globe.
Although we cannot estimate the full extent of wildlife trade, we can use the Convention on International Trade in Endangered Species (CITES) to assess the legal trade of around 6,000 animal groups. CITES focus on whether wildlife trade is legal and sustainable (setting quotas to ensure population numbers do not drastically reduce), however, zoonotic disease prevalence in wildlife trade does not fall into their remit. Previous studies have investigated whether a handful of zoonoses are prevalent in CITES-listed live animal trade, but new research has emerged that covers a broad range of zoonoses in both live and raw animal parts (i.e., trophies, skins and bones).
Could CITES play a meaningful role in controlling zoonoses?
Research indicates that 44% of CITES-listed animal groups such as bears, canines (wolves, foxes, dogs) and felines (tigers, cheetahs, cats) are associated with a zoonotic disease. What’s worse, just under 50% of these zoonotic diseases fall under the OIE’s 25 zoonoses that pose high-risk to human health. Are wild pets, traditional medicines and exotic foods really worth the risk of the next pandemic?
Approximately 300,000 CITES live animal transactions occurred between 2009 and 2018 using animals associated with zoonotic risk. Whilst this is only 29% of all CITES live animal transactions in this timeframe, this still equates to 26.5 million individual animals being trapped in crates and shipped hundreds of miles overseas. When it comes to the trade of animal parts, birds and reptiles are the most common animals to have their parts traded and possess a significant zoonotic risk. These parts include the skins of alligators, crocodiles and pythons, the pelts and trophies from bears and felines, and physical dead specimens of baboons and macaque monkeys.
Animal parts do not only include crocodile skins for a handbag, or the heads of lions as trophies to mount on your wall. Between 2009 and 2018, 12% of all CITES exported meat trades came from animal groups associated with at least one zoonotic disease, with the most popular meats coming from crocodiles. To put this into perspective, 23.5 million kg of meat traded over these ten years came from animals associated with harbouring diseases that can be passed on to humans!
What can be done to help reduce the zoonotic risk of the wildlife trade?
CITES could play a significant role in addressing the zoonotic risks present in the international wildlife trade, however, they cannot work alone in mitigating the next pandemic. There are several actions that can be taken to help us understand this problem better, and recommendations based on current knowledge on how we can reduce the risk:
Adopt the ‘One Welfare’ Framework
We are pushing for the key players of the International quartet of OIE, FAO, WHO and UNEP to adopt this holistic framework which considers human, wildlife and livestock health holistically. By establishing a cooperative relationship between these global organisations and CITES, we could ensure that research specific to wildlife trade and zoonoses is identified and prioritised.
Create a centralised zoonoses database
Collating all known zoonotic diseases and the associated species that possess these pathogens would create a vital resource that current databases lack. Through regular updates we could create a comprehensive collection that could be accessed globally and allow for more sophisticated and rigorous analysis. When put into practice, this database could be used to cross reference a new zoonotic disease with species that carry the pathogen, and a blanket ban on said species trade could limit the spread.
Research illegal trade & non-CITES species
By limiting ourselves to CITES-listed legal trades, we are only getting half the story. For a comprehensive idea of the connection between wildlife trade and zoonoses, we must factor in the trade of non-CITES species and use CITES illegal trade reports to better understand the pathogen pathways of illegal trades.
In the wake of COVID-19, it is understandable that our focus is to mitigate the current spread of infection and control the emergence of new variants. However, to truly reduce the risk of another pandemic, we must focus on prevention. To completely prevent the spread of zoonotic disease in the global trade of wild animals, we must end the global trade of wild animals. The commercial wildlife trade has already caused SARS, Ebola and HIV to name but a few, and if we continue to exploit wildlife, it will not be long before we see lockdown again.