Environmental Degradation Creates Opportunity for Future Pandemics

Health officials aren’t quite sure how the COVID-19 outbreak began. Though news outlets have been quick to jump on possible suspects, including bats, pangolins, and snakes, consumption of these wild animals is not necessarily the cause. As we infringe on our natural habitats, zoonotic diseases, or those that spread from other animals to humans, may become more common in our society. Diseases like MERS, SARS, Ebola, and avian influenza were probably caused by close contact with wildlife rather than consumption.

Here, we explore how common wildlife consumption is in China, rules and regulations, and why the outbreak probably didn’t start by someone eating bat wing soup.

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A napping cat outside Shekou wet market In Shenzhen, China – Laurel Chor/NPR

Consuming Wildlife In China

In regards to Chinese wildlife consumption, factors including peer and societal pressure, tradition, and desire for status are often involved. The notion that all Chinese eat legal/illegal wildlife is false. In fact, the trend appears to be largely regional and associated with income and educational level.

In a 2014 study, researchers surveyed 1065 people from five cities (Beijing, Shanghai, Guangzhou, Kunming, and Nanning). Four types of behavior were surveyed, including using wildlife for food, medicine, garments, or keeping wild animals as pets. 52.7% of respondents said wildlife should not be consumed, compared to 42.7% in a similar 2004 study. In Guangzhou, 83.3% of respondents said that they had consumed wildlife in the past year, compared to only 4.9% in Beijing. Interestingly, the survey found that younger people with college level education and higher monthly income were actually more likely to eat wild animals than their less educated, poor peers. And while many western cultures believe that Chinese citizens commonly consume wildlife, survey participants reported eating wildlife only 2.7 times per year (on average).

wildlife consumption
(2004 – Li Zhang) This study found that those with higher incomes and education were more likely to be consumers of wildlife.

Wildlife Trade and Legality 

The illegal wildlife trade is worth billions of dollars and is dangerous to the biodiversity of ecosystems and livelihood of endangered species. Those in extreme poverty are driven to poach and trade illegal wildlife to ensure economic stability or resources. In Vietnam, misinformation about rhino horn as a cure for cancer has motivated large scale poaching in South Africa. The price of this horn rivals that of gold, but is made of keratin, the same material found in our fingernails.

Not all wildlife is illegally sourced however. When China announced a permanent ban on the trade and consumption of wild animals, the scale of the legal wildlife farming industry began to come to light. After severe economic hardship and mass fatality following Mao Zedong’s farming policies during the Great Leap Forward, the 1970s led to wildlife farming as a prospective way to create economic stability amongst rural citizens. This month, as the new ban on wild animals consumption was enforced, around 20,000 wildlife farms were shut down. These farms were breeding a variety of wild animals like porcupines, peacocks, and foxes, amongst others. Farms also continued to breed and sell civet cats, which were most likely the vector of the SARS virus in 2003.

Civet cats were still being bred and sold from wildlife farms, even after the 2003 SARS outbreak. Photograph: China Photos/Getty Images

As new rules are put place, experts are concerned that swift moves to remove wildlife from markets will only ensure that they move underground. Erin Sorrell, an assistant research professor in the department of microbiology and immunology at Georgetown University, notes that with zero transparency, the risk of infectious disease outbreaks could increase.

“I would love to see wildlife be removed from markets, full stop,” she says. But if a ban is rushed without careful consideration, the entire wildlife trade could move underground, making it “even more dangerous for [a product] to be consumed because we’re not seeing where it’s being consumed or where it’s coming from.”

The Tai Po market in Hong Kong, where people can buy live seafood. Jason Beaubien/NPR.

Why Consumption May Not Be the Cause

Many news sources have stated wet markets are the cause of the novel coronavirus and must be shut down immediately to ensure public safety. Not all wet markets, however, sell wild or living animals and commonly contain the most accessible and nutritious ingredients available, or local produce in smaller towns. According to a 2012 study, a child’s nutritional intake was positively correlated with the density of wet markets in their area.

Beyond the case of the value wet markets, consumption of wildlife sold in markets may not necessarily be the cause of the virus. Since many early cases included patients who had not gone to wet markets in Wuhan, where COVID-19 started is still unclear. Furthermore, other zoonotic disease outbreaks globally probably had no link to the consumption of wild animals. The Ebola virus outbreak in West Africa, which was initially thought to be caused by eating bush meat, is now thought to have started by a young child playing inside a tree with roosting bats (probably through the ingestion of droppings). MERS, a type of coronavirus, likely spread from camels to humans due only to close contact. And avian influenza is most likely spread through infected bird droppings or other bodily secretions, rather than consumption.

The tree where the Ebola virus likely originated. Children often played inside the stump, which was inhabited by infected bats. FABIAN LEENDERTZ.

The 2003 SARS-CoV outbreak was most likely not caused by eating civets in China, but rather handling them in farms, markets, or prior to cooking. As such, COVID-19 could easily have found other ways to cross over into humans, either through illegal trafficking, wildlife farms, or close contact in markets.

 

Encroaching on Habitat

As humans continue to infringe on the barriers of natural spaces globally, further interaction between our species and other animals will be unavoidable. While certain diseases like malaria infringe on our world, rises in zoonotic diseases can mostly be attributed to our encroachment on wild space.

One study found that a 4% increase in deforestation in the Amazon rainforest increased local malaria cases by 50% due to increase in an open, moist environment for mosquitos to breed. Suburbanization in Australia forced bats into public spaces and farm land, causing transmission of the Nipah virus. And in the United States, the increase in the fragmentation of forests has caused predators of the white-footed mice to disappear, creating a huge boom in Lyme disease (white-footed mice are the initial host of the disease, while ticks are vectors).

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Fragmentation can lead to lower biodiversity and loss of predators. This allows for species like the white-footed mice to be more successful hosts of Lyme disease. Well Sites, Dimock, PA. © 2010 J. Henry Fair

These environmental damages, along with those created by illegal poaching of wildlife, have come to light as the novel coronavirus outbreak spreads globally. The PREDICT project records and predicts threats of viruses capable of starting potential outbreaks, and uses this data to help inform decisions on infrastructure, agriculture, and healthcare. This alone will not be enough to ensure another zoonotic disease doesn’t cause a global pandemic in the future. Further consumption of fossil fuels will continue to exacerbate climate change, increasing habitat for species like mosquitos. Deforestation will continue to force wildlife in our backyards. And failure to create unity in the regulation of wildlife will push us into more dangerous situations. 

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One Health Initiative

This virus could help us realize that our ability to reduce fossil fuel consumption, ban harmful activity, and allow our environments to replenish themselves were possible all along. It could also bring us together as one force to push for significant changes in our governments, corporations, and communities. I’ve heard several people say that this outbreak was the earth’s way of telling us to assess the actions we make daily. It’s up to each of us to keep assessing them, even after this is over.

 

Top Image: Civet Cat – Flickr: luwak (civet cat)

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