The COVID-19 pandemic has ravaged the world, infecting 134 million and killing nearly 3 million people. The SARS-CoV-2 virus that causes the COVID-19 disease is thought to have likely originated in bats, a misunderstood and often maligned order of mammals that includes over 1,400 species. How the virus jumped the species barrier remains unclear, but strong evidence exists linking the wildlife trade to human exposure to the virus.
It is important here to make the distinction that this trade includes both legal and illegal trade, the latter of which is often referred to as wildlife trafficking. While one would like to imagine that the legal trade would provide safeguards against zoonotic disease transmission, one account by a former U.S. Fish and Wildlife inspector states that “[other than a] few exceptions, the U.S. has no laws specifically requiring disease surveillance for wildlife entering the country, and the vast majority of wild animal imports are therefore not tested”. The Centers for Disease Control does work with the U.S. Fish and Wildlife Service as well as international authorities to monitor zoonotic disease threats, but their focus is on known carriers of zoonoses4. This means that constantly evolving pathogens that can cause pandemics can easily travel along with novel host animals traded live across international borders for various purposes.
To put the scale of the wildlife trade into perspective, approximately 200 million live animals are imported into the U.S. annually, providing an avenue for zoonotic diseases to enter the country. It is difficult to quantify the global scale of the wildlife trade, but it is surely many times greater in volume, bringing foreign species with any pathogens they may be carrying to their destination as they travel across the globe.
So, what can be done to prevent the next pandemic?
Some argue a blanket ban on wildlife trade may be warranted. Others argue for a narrower ban on commercial trade for human consumption (particularly of birds and mammals), or stricter regulations on wildlife trade with potential bans accompanied by a suite of policy actions to ensure the root causes of zoonotic disease transmission, such as habitat destruction and fragmentation, are addressed. Others call for the closing of wildlife ‘wet markets’, particularly those that sell live mammals and birds, that are ideal breeding grounds for zoonotic diseases, along with the provision of assistance to those that derive their livelihoods from such markets. In contrast, some argue that banning the wildlife trade would be detrimental to communities and businesses that rely on wildlife for their livelihoods, and the ‘blanket bans’ that are called for by some “may provide cover for inaction on issues that would make a true difference in preventing future pandemics”. Where does this leave us? Perhaps it is worth digging into these policy suggestions more deeply.
First, a blanket ban on “wildlife trade” writ large simply will not happen. The reason behind this is that the trade in wild animals includes a massive number of species that we may not even think of when we imagine wildlife—fish and invertebrates, for example— and many wildlife species are simply not carriers of the kinds of zoonotic diseases that have (at least historically) caused pandemics. Alternatively, some experts suggest focusing on birds and mammals in particular, especially those sold in wet markets, because major epidemics from the past two decades were caused by birds (Avian flu) and mammals (Severe Acute Respiratory Syndrome, or SARS and Middle East Respiratory Syndrome, or MERS, and Ebola). By ending the trade in such species, especially for human consumption, and the wet markets at which live mammals and birds are sold, it would shut down one pathway by which diseases can be transmitted from wild animals to humans (and then on to other humans).
However, this is only part of the problem. Another underlying issue, as mentioned briefly above, is the destruction and fragmentation of wildlife habitat, which brings human settlements much closer to wild animals. In fact, researchers have been warning of the potential for zoonoses and emergence of novel infectious diseases due to human encroachment on wildlife habitat for decades. This phenomenon, coupled with rising exploitation of an increasingly wide array of wild animals for human consumption, brings live wild animals (which can host zoonoses) in close proximity to other animals and humans, where they can spread viruses and other pathogens. This may be what occurred in the Huanan Seafood Wholesale Market in Wuhan, China with SARS-CoV2.
Where does this leave us?
What should we do? In response to calls to create a new international convention to address zoonoses, which would be time-consuming and costly, some have argued that existing international agreements like the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) might be able to address zoonotic disease transmission resulting from the wildlife trade. Others disagree, arguing that CITES—a Convention that regulates the trade in wild animals—neither includes considerations of the effects of said trade on health of humans or other animals, nor does it in any way regulate the thousands of species in trade that are not listed in its Appendices. It is worth noting that the CITES Secretariat itself has stated that it “does not have the competence to makes comments regarding…possible links between human consumption of wild animals and COVID-19” and suggests that the World Organization for Animal Health (OIE) or the Food and Agriculture Organization of the United Nations may be better suited to address the prevention of zoonotic diseases.
The bottom line is that we need to address the root cause of zoonotic disease transmission – the commercial trade in wild animals for human consumption. Yes, habitat loss or fragmentation is a major threat to countless wild animal species. Encroachment of human settlements on wild areas that serve as habitat for animals that have never come in contact with humans has the potential to cause zoonotic disease transmission. However, it is the large-scale exploitation of wildlife for commercial purposes that puts a wide variety of wild animals in one marketplace where they can exchange pathogens that can cross the species barrier. Indeed, just over a week ago, the World Health Organization, the OIE and the United Nations Environment Programme issued interim guidance urging countries around the world to “suspend the trade in live caught wild animals of mammalian species for food or breeding purposes and close sections of food markets selling live caught wild animals of mammalian species as an emergency measure” to reduce related public health risks.
While this has been a tragic year in which millions of people have suffered and died, we must not forget that one million wildlife species are now facing extinction. To address this and the threat of zoonotic disease transmission, sweeping bans on commercial trade in wildlife for human consumption should be enacted with narrow exemptions for true subsistence. Doing so is a massive undertaking but one that countries can enact independently. Overall, there needs to be a shift in our thinking away from the utilitarian “use it ‘till we lose it” mindset toward a bold, precautionary approach. We must take action before it is too late for wildlife and before the next—perhaps inevitable—pandemic.
Adam Peyman is a 2021 Candidate in the Environmental Studies Master's of Science program.