The Importance of Conservation: How the Wildlife Trade Caused a Pandemic
In December 2019, 66% of the 41 people first hospitalized with COVID-19 were traced back to passing through the same wet market (a market that sells live animals and wildlife) in the heart of Wuhan, China (Hassanin, 2020). It is believed “close contact with the blood, secretions, organs or other bodily fluids of infected animals such as fruit bats, chimpanzees, gorillas, monkeys, forest antelope or porcupines found ill or dead or in the rainforest”(WHO, 2020) led to the first crossover of Ebola virus to the human population in 1976. Other familiar diseases caused by human animal contact include Hepatitis, HIV, SARS, and tuberculosis.
We’ve all heard of the famous diseases caused by animal-borne pathogens – such as the black plague and Spanish flu – but over the past decades viruses that cross over to human populations are increasing. For some, like swine flu, this can be traced back to our unsustainable animal agriculture tactics of globalization and mass production (Smith, 2009), which creates the perfect environment for illnesses in animals to spread and evolve, eventually carrying over to the people working around them. But Ebola Virus Disease, AIDS, and COVID-19 were all caused by something different.
Most scientists suspect that these viruses transferred to humans through close contact with animals who carried them, and in the places where they originated, the most likely cause for this was the practice of eating bushmeat. Bushmeat is defined as wildlife hunted for food. Often bushmeat includes rare species of turtles, monkeys, bats, and even great apes. COVID-19, is currently thought to be a chimera virus (formed from the recombination of two different viruses) that spread to humans from live wild animals commonly found at wet markets in Wuhan (Hassanin). According to the CDC, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) are examples of diseases caused by coronaviruses that originated in animals and spread to people. This is what is suspected to have happened with the virus that caused the current outbreak of COVID-19. In the SARS outbreak of November 2002, also in China, the virus originated from wild bats. Hassanin (2020) notes that bats of the genus Rhinolophus (potentially several cave species) were the reservoirs for this virus and that a small carnivore, the palm civet, may have served as an intermediate host between bats and the first human cases. A reservoir species is one in which a virus normally lives, grows, and multiplies.
The problem with people eating wildlife arises from the lack of control over wildlife trade. Where domesticated meat animals are (usually) at least medicated and bred to prevent sickness and pathogens transferable to humans, most wildlife found in wet markets are very sick, whether from before they were caught or the stress they are under, or even just the filthy conditions they are often kept in (Karesh, 2005). They are not normally quarantined or checked for health, and since usually most of their lives have been in the wild, there is no way to know what diseases these animals have been exposed to. People who touch, slaughter, and eat these animals are at a higher risk for infection as there is no way to know what pathogens animals are infected with, and many types of bushmeat are consumed undercooked or in unconventional ways because of traditional practices. In today’s globalized world, if someone gets sickened by disease from eating undercooked bushmeat, that disease has the opportunity to spread rapidly worldwide.
Dr. Karesh, the director of the Wildlife Conservation Society’s Field Veterinary Program and co-chair of the World Conservation Union Veterinary Specialist Group, completed a paper explaining the source of zoonotic (animal borne) diseases resulting from wildlife trade. Karesh argues that the global trade in wildlife provides disease transmission mechanisms which not only cause human disease outbreaks but also threaten livestock, international trade, rural livelihoods, native wildlife populations, and the health of ecosystems:
“In lieu of precise trade data, we conservatively estimated that in East and Southeast Asia, tens of millions of wild animals are shipped each year regionally and from around the world for food or use in traditional medicine. Hunters, middle marketers, and consumers experience some type of contact as each animal is traded. Other wildlife in the trade is temporarily exposed, and domestic animals and wild scavengers in villages and market areas consume the remnants and wastes from the traded and potentially traded wildlife. These numbers combined suggest that at least some multiple of 1 billion direct and indirect contacts among wildlife, humans, and domestic animals result from the wildlife trade annually. The increasingly global scope of this trade, coupled with rapid modern transportation and the fact that markets serve as network hubs rather than as product endpoints, dramatically increases the movement and potential cross-species transmission of the infectious agents that every animal naturally hosts.”
SARS-CoV-2 is currently thought to be a mutated coronavirus from pangolins, which act as a reservoir, and another coronavirus possibly from bats or civets (Hassanin). Pangolins are critically endangered, yet still the most trafficked wild animal in the world, as their slow moving gait makes them easy to catch and their unique keratin scales are believed to be magical in traditional medicine, a belief that is causing extreme cruelty to these animals and the imminent extinction of the species. On February 7, the closest virus to SARS-CoV-2 was discovered in a pangolin, and that isolated coronavirus possessed specific cellular binding protein receptors that allow it to bind with and enter human cells, whereas the coronavirus from bats do not (Hassanin). This suggests that SARS-CoV-2 likely evolved from the thousands of pangolins trafficked through China which eventually ended up in Wuhan, where the virus had the opportunity to interact with other viruses from different animals and eventually became the coronavirus so deadly to humans.
We can see from the COVID-19 pandemic that we cannot afford to continue going through global disasters caused by human activity. The possibility of emerging infectious diseases spreading between persons and animals is rising, fueled by human activities ranging from the handling of bushmeat and the trade in exotic animals to the destruction or disturbance of wild habitat. In a list of 1,415 human pathogens, 61% are known to be zoonotic (transmissible from animals to people), and multiple host pathogens are twice as likely to be associated with an emerging infectious disease of humans (Karesh, 2005). If we limit the amount of human-wildlife contact and give wildlife a place to be that isn’t near humanity, we can decrease the exposure rate and avoid the pain caused by these diseases. Outbreaks resulting from wildlife trade have caused hundreds of billions of dollars in economic damage globally, and this pandemic will be no different. Job loss, poverty, and economic recessions are on the rise as we are forced to stop our ways of life because of this virus (Karesh, 2005).
Rather than attempting to eradicate pathogens or the wild species that may harbor them, we must decrease the contact rate among species, including humans, at the interface created by the wildlife trade. Focusing efforts at markets to regulate, reduce, or in some cases, eliminate the trade in wildlife could provide a cost-effective approach to decrease the risk of disease for humans, domestic animals, wildlife, and ecosystems. Obviously, these measures need to be supplemented with programs to give the people who earn their livelihood from wildlife trade or poaching an alternative job choice, and community outreach is essential to teach people wildlife is to be respected, not coveted.
As ecosystems begin to degrade beyond recovery, we will see an exponential rise in natural disasters caused by imbalances such as extreme weather events, climate change, and even pandemics caused by human encroachment into remaining habitats and globalization. As the saying goes, what goes around comes around, and if anything positive can come from coronavirus, perhaps it can be a wakeup call that we cannot continue to allow the practices destroying earth’s ecosystems-which we and all other life on earth depend on-to continue.
A Humane World, 27 Mar. 2020, blog.humanesociety.org/2020/03/to-prevent-another-pandemic-global-leaders-should-crack-down-on-wildlife-trade.html.
“Ebola Virus Disease.” World Health Organization, World Health Organization, 10 Feb. 2020, www.who.int/news-room/fact-sheets/detail/ebola-virus-disease.
Hassanin, Alexandre, and Sorbonne Université. “Coronavirus Origins: Genome Analysis Suggests Two Viruses May Have Combined.” World Economic Forum, 20 Mar. 2020, www.weforum.org/agenda/2020/03/coronavirus-origins-genome-analysis-covid19-data-science-bats-pangolins/.
“If You Have Animals.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 27 Mar. 2020, www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/animals.html.
Karesh, William B, et al. “Wildlife Trade and Global Disease Emergence.” Emerging Infectious Diseases, Centers for Disease Control and Prevention, July 2005, www.ncbi.nlm.nih.gov/pmc/articles/PMC3371803/.
More Chinese Push to End Wildlife Markets as WHO Declares Coronavirus Emergency, 17 Mar. 2020, www.nationalgeographic.com/animals/2020/01/china-bans-wildlife-trade-after-coronavirus-outbreak/.
Wildlife Alliance, 7 Aug. 2019, www.wildlifealliance.org/world-pangolin-day-2019/.