For all the controversy surrounding the true origins of SARS-CoV-2—the virus which caused the pandemic disease COVID-19—there's one thing public health officials and experts can agree on:
The virus jumped to humans from animals through a phenomenon called zoonotic transmission.
Unfortunately, this isn't the first time that the consumption and mistreatment of animals has been implicated in the ignition of a worldwide health outbreak.
The Animal Origins of the Novel Coronavirus and Other Pandemics
Speculations and rumors have long circulated that the true origin of SARS-CoV-2 came from a bioweapons lab at the Wuhan Institute of Virology in Wuhan, China. In this lab and other ones like it, animal research and experimentation is routinely performed.
These rumors spiked after reports came that United States officials were investigating whether the virus began in a laboratory before spreading to the now-infamous Wuhan wet market, where dead and live animals are traded and sold, often illegally and in cramped, dirty, deplorable conditions. Other evidence counteracts these rumors, however, including a March 2020 study published in Nature Medicine which found that the genetic sequence of SARS-CoV-2 suggests it was not engineered but rather evolved naturally in bats and/or pangolins (similar to an anteater).
Cultural differences notwithstanding, officials from around the world, including the Biodiversity Chief for the United Nations, have called for a closure of these wet markets in an attempt to prevent future infectious disease outbreaks and to end the mistreatment and illegal trade of animals and wildlife.
The condemnation has it's merit. Just look at these other historical cases of animal-to-human pathogens linked to close contact and handling:
H5N1 Avian Flu
According to the Centers for Disease Control and Prevention (CDC), this virus was first detected in geese in China in 1996. An H5N1 outbreak in Hong Kong in 1997 was attributed to human exposure to infected chickens. Over 1.5 million chickens were slaughtered in December of that year, effectively ending the outbreak which infected 18 people and killed six. Since December 2003, over ten countries have reported additional human H5N1 cases, most of them occurring due to "prolonged and close contact with infected sick or dead birds" and visits to live poultry markets.
While relatively rare in humans, the H5N1 avian flu leads to death in up to 60 percent of cases, most of which occur in young adults and children between the ages of 10 to 19 years old.
The CDC notes that scientists don't know for sure where the deadly ebola virus originated from, which was first discovered in 1976 in what is now the Democratic Republic of Congo. The leading hypothesis is that the virus began in bats and non-human primates including monkeys, chimpanzees, and apes. The first humans to become infected came in contact with bodily fluids and tissues of infected animals because of illegal selling and handling of so-called bushmeat, the meat of these wild and in some cases endangered animals.
Ebola outbreaks continue to happen to this day, with the most famous one occurring between 2014 and 2016.
Between November 2002 and July 2003, the world faced an outbreak of a viral illness known as severe acute respiratory syndrome (SARS). More than 8,000 people in 26 countries contracted the illness. It's believed to have originated in bats and spread to other animals, including civet cats, before passing to humans.
Since that time, a small number of additional cases of SARS have occurred due to animal-to-human transmission or as a result of confirmed laboratory accidents, as noted by the World Health Organization.
It may not be possible to completely prevent future pandemics, and for now there is no conclusive proof as to where and how the current novel coronavirus pandemic began. However, experts believe that cracking down on illegal and unethical animal trade and handling practices will be key to reducing the risk of future public health crises, not to mention preserve endangered wildlife and biodiversity around the globe.