Whilst the pandemic continues to affect all walks of life, what do we know about its origin? Research suggests that emerging diseases find their origin from animal populations under conditions of severe environmental pressures. Although the specific origin of the coronavirus has not been detected, well-established theories and ideas have been proposed by scientists. One of those is that the virus started in bats and got into humans through a secondary host of pangolins.
But how did it get into humans from pangolins? One possible answer: wet markets. The initial coronavirus outbreak was declared in Wuhan in 2019, where there is a large live animal market. In such markets, wild and domesticated animals - including bats - are typically kept and stored in crowded conditions and in close contact both with other animals and with humans. When animals are stressed in these conditions, viruses such as COVID-19 can jump to animal handlers or customers through exposure to an animal’s bodily fluids.
During past pandemics, bats were a key contributor to the spread of zoonotic diseases. In the same way, the theory of the origin of COVID-19 is that diseases from bats spread to another animal which then spread the coronavirus to humans, or that bats spread the disease to humans directly. Wet markets, like the one in Wuhan, create the perfect conditions for novel viruses to emerge.
In order to prevent further pandemics, when exotic animals are for sale, they should be banned from being stored in such conditions.
The destruction of natural ecosystems is key in producing animal to human virus transmission. In 2018, 30 million acres of tropical rainforest were destroyed. Over a third of the world’s land is used for agriculture, which requires the clearing of woodlands in order to create pasture.
A study which analysed 6,800 ecological communities on 6 continents found that there is a connection between human development and biodiversity loss, and disease outbreaks.
“We’ve been warning about this for decades,” says Kate Jones, an ecological modeller at University College London and an author of the study, published August 5 in Nature.
Human settlements are increasingly coming in proximity to animals that carry infectious diseases that had previously been contained in woodland habitats. This is something that has only been exacerbated with growing human populations.
Virologists, economists and ecologists published an essay in Science, suggesting that governments can help reduce the risk of future pandemics by controlling deforestation.
Whilst larger predator species are going extinct, in the battle of ‘survival of the fittest’ those that tend to thrive and overpopulate are small rodents, such as rats and bats. They are more likely to carry dangerous diseases that make the jump to humans.
But what’s causing the extinction? Scholastic notes five major causes:
An introduced species
Infectious diseases as a result of human-animal interaction
76 million infected worldwide - was started when humans ate bush meat in the Cameroonian jungle.
Fruit bats attracted to human fruit fields. It started through a human coming into contact with bodily fluids of an infected animal.
Host mosquito that thrived in densely populated, urban areas.
Linked to logging in the Amazon. Control efforts brought annual numbers down from 6 million in the 1940s to 50,000 in the 60s. However, the numbers have been rising annually ever since.
SARS and Bird Flu
The number of cases has increased in the past few decades. Likely to be the result of increased contact between humans, wildlife and livestock as people move into underdeveloped areas, disrupting the natural ecosystem that lives there.
How our environment increases our risk of catching coronavirus
“Those who live in more polluted environments, areas where there are more particulates in the air and more ozone smog, are more likely to have problems with their underlying asthma or chronic lung conditions,” Mona Sarfaty, MD, MPH, founding director of the Medical Society Consortium and Climate and Health at George Mason University, said. And “it’s been all over the news that people who have become infected with coronavirus are more likely to crash if they have an underlying compromise with their lungs because of an underlying condition.”
Living in a poorly kept environment increases the likelihood of catching a bad case of coronavirus.
It is clear that our relationship with the environment, whether that be deforestation, wet markets or pollution, is the cause and reason why coronavirus is so prevalent worldwide today.
For more resources on the environment, head to our dedicated Climate Crisis section.