A new report, “Animal Markets and Zoonotic Disease,” published in 2023 through Harvard’s Brooks McCormick Jr. Animal Law & Policy Program and NYU’s Center for Environmental and Animal Protection, overviews the serious future pandemic risks associated with a wide range of animal industries in the United States. The report analyzes 36 different animal industries, which use animals of wild, agricultural, or otherwise human-produced origins, in which close and unsafe human-animal interactions occur routinely. These industries include, but are far from limited to, the exotic pet trade, pet stores, hunting, trapping, zoos, aquariums, animals in research, and large-scale instances of animal production for food and fiber, like fur farming, industrial animal agriculture, and big game farming.
Concerningly, the report discovered that most of these industries are substantially less regulated than they should be, and far less standardized than the public believes. Consequently, pathogens may be transferred from animals to humans freely, which can result in the dangerous spread of zoonotic diseases. Our understanding of the severity of zoonotic disease spread was amplified during the COVID-19 pandemic, which likely originated from human exposure to infected wildlife, and resulted in the death of over one million Americans.
The Lessons Learned from the COVID-19 Pandemic
Thought to have originated in a wildlife market in China, COVID-19 also spread rampantly at mink farms across Europe and throughout North America, demonstrating that COVID-19 could be transferred between mink and from mink to humans. These outbreaks resulted in the deaths of millions of mink around the world. Unfortunately, as is the nature with increased opportunities for zoonotic disease transfer, the production of new virus variants, and virus spillover (the transfer of pathogens from humans to nonhuman animals), a future pandemic could have an even greater impact on life as we know it; potentially, and terrifyingly, greater than the immense upheaval felt from the most recent one.
The Exotic Pet Trade Is an Especially Dangerous Avenue for Potential Disease Spread
The sheer volume of animal use and production in the U.S. makes it a uniquely vulnerable location for a future pandemic to arise. For example, the U.S. is the largest importer of live wildlife in the world, importing more than 220 million wild animals in one year, many without undergoing any health checks or disease testing prior to entry.
The U.S. is the largest importer of live wildlife in the world, importing more than 220 million wild animals in one year, many without undergoing any health checks or disease testing prior to entry.
The U.S. exotic pet trade, valued at $15 billion annually, is major vector through which high-risk human-animal interactions can be potential opportunities for zoonotic disease spillover. By some estimates, there are as many exotic pets in the U.S. as there are cats and dogs. Approximately 14% of American households own one or more exotic animal from a wide range of species, including primates, birds, reptiles, and fish. Alarmingly, from just primates alone, humans can contract up to 200 known diseases, many of which can be fatal. We do not yet know of the impact future transferrable diseases may have on human health.
Further, animals in the exotic pet trade, through both legal and illegal avenues, are often sold to owners without any disease testing or veterinary oversight. Despite this overt lack of regulation and failure to prioritize human public health and safety, estimates suggest these non-native wild animals captively bred in the U.S. altogether number in the tens of millions. Some exotic animal dealers keep more than 25,000 wild animals together at a single facility, often in poor and tightly-packed conditions that facilitate disease spread, before being distributed to customers across the country.
Animals in the exotic pet trade, through both legal and illegal avenues, are often sold to owners without any disease testing or veterinary oversight.
For example, during a major mpox (previously referred to as “monkeypox”) outbreak, which originated in one of these large facilities that received a shipment of exotic animals from overseas, CDC agents were not able to track down a large number of infected prairie dogs that had already been sold through pet stores and swap meets. These animals potentially infected numerous humans with the virus down the length of the supply chain. Even less popular and more niche animal industries in the U.S. pose serious risks to human health, like crocodile farms, which have facilitated the spread of West Nile Virus to humans.
Hunting and Trapping Industries Also Pose a Risk of Zoonoses
Regarding the hunting and trapping industries, there are several discrete potential animal-human contact points that could facilitate zoonic disease transmission, such as being bitten or scratched by an animal caught in a trap or handling fresh carcasses. Pathogens can be contracted from live or recently deceased animals, and both hunting and trapping require direct human contact with wild animals who were recently killed or injured. Further, studies have indicated that many hunters are uninformed about zoonotic risks and take few precautions to avoid them. For example, only 16% of duck hunters wear gloves when handling and defeathering dead birds, when wild aquatic birds are the natural reservoirs for avian influenza and have transmitted low pathogenic strains of virus to hunters.
Dozens of other zoonoses are present in hunted species throughout the U.S. like bison, white-tailed deer, and elk, including rabies, tularaemia, tuberculosis, and Hantavirus Pulmonary Syndrome. Despite all the associated risks, most states do not impose sanitary requirements on hunters, such as requiring the use of gloves, other personal protective equipment (PPE), or hand washing when handling dead animals, and do not typically regulate the disposal of carcasses. Trapping is even less regulated than hunting.
Dozens of other zoonoses are present in hunted species throughout the U.S. like bison, white-tailed deer, and elk, including rabies, tularaemia, tuberculosis, and Hantavirus Pulmonary Syndrome.
Zoos Also Pose a Public Health Risk, Especially When Directly Physical Contact between Animals and People Is Allowed and Encouraged
Many zoos allow physical interactions between the animals and visitors. Disease exposure at zoos can happen anytime this contact occurs, through touching, holding, or feeding an animal, as well as by being licked, bitten, or scratched. Indirect transmission can also occur through inhaling airborne pathogens or interacting with pathogens in the animal’s food, water, or environment. Children are especially vulnerable to these exposures, as they are more likely to take fewer sanitary precautions to mitigate zoonotic risk. The suboptimal living conditions provided by zoos including poor nutrition, health, and housing all function to increase the chronic stress levels experienced by the animals, leading to weaker immune systems and an increased likelihood of contracting and spreading disease.
The U.S. Has No Comprehensive Strategy in Place to Managed Zoonotic Disease Risk
Ultimately, the report comes to a troubling conclusion: the U.S. has no comprehensive strategy to mitigate zoonotic risk. Instead, policy change is often reactive, happening only after outbreaks occur. By then, it is often too late. For many industries, the government lacks even basic data about animal facilities, has no appointed governing body for animal welfare or health inspections, no system in place to screen animals for disease or to identify zoonotic threats proactively, and does not have the staffing capability to accomplish these goals effectively for the several thousands of animal facilities in operation.
Policy change is often reactive, happening only after outbreaks occur.
To begin the process of fixing this highly flawed system, the report emphasizes the importance of the world combatting future pandemic risks through a united front in global policy response. This approach can only be accomplished by adopting the understanding that future pandemics can happen anywhere, at any time, as long as the lack of animal-related regulations continue to neglect human public health and safety measures.
For example, as the report states, “For many Americans, concepts such as “bushmeat” or “wildlife farming” seem foreign, but they refer to practices that are common within the United States as well, differentiated only by the language we use to describe them.” It is often easy to turn a blind eye to something typically perceived as out of sight, but far more difficult to do so when the next pandemic is staring us right in the face; especially when more emerging infectious diseases originated in the U.S. than in any other country in the world during the second half of the 20th century. Given our track record, the U.S. owes it to the rest of the world to finally prioritize the animal-related human health measures we have so long been neglecting, and consider which industries are no longer justifiable to continue based on the associated risks to us and horrific impacts on the animals themselves.
Keep Wildlife in the Wild,
Devan
