Diseases such as COVID-19 have been predicted by various disease ecologists.
In Spillover: Animal Infections and the Next Human Pandemic, David Quammen wrote in 2012 about the likelihood of virulent infectious diseases because of urban sprawl, pesticides and international trade, which has altered ecosystems and damaged biodiversity, letting loose the viruses that were once confined to wildlife.
Dr Peter Daszak, a contributor to the World Health Organization Register of Priority Diseases, called it Disease X in 2018, well before COVID-19 broke out.
The number of new infectious diseases has tripled each decade since the 1980s: there have been at least 300 in the past 50 years, 72% of which originated in wildlife.
Ebola arrived via a chimpanzee that was caught and consumed in Gabon; it killed 90% of infected people. It is suspected to have been passed on to chimpanzees from bats, forced to inhabit the same ecosystems and compete for the same food sources by deforestation.
Middle East Respiratory Syndrome (MERS) passed from bats to camels and then to the camel handlers. Hendra virus came from fruit bats, urbanised because of loss of habitat, and was passed on to horses and people.
Kyasanur Forest Disease in India spread from monkeys to humans via ticks as monkeys invaded human territory when theirs was lost through deforestation.
Nipah virus in Malaysia spread from fruit bats driven from the forest by clearing on to mango trees, into pigs via bat droppings and saliva, and then on to the farmers. HIV-AIDS, Zika, Severe acute respiratory syndrome (SARS), bird flu and West Nile viruses all came from wild animals.
COVID-19 is likely to have passed by bats to another animal, possibly a pangolin, then on to humans trading in wild animals.
David Quammen said: “We cut the trees, we kill the animals or cage them and send them to markets. We disrupt ecosystems, and we shake loose viruses from their natural hosts. When that happens, they need a new host. Often, we are it.”
As Joachim Spangenberg from the Sustainable Europe Research Institute wrote: “We are creating this situation, not the animals”.
Ending the trade in wildlife sounds like a simple solution but suppression could drive it underground where hygiene is likely to be worse. Many people are dependent on the trade for their income and sustenance.
The issues of poverty, unemployment and food insecurity need to be addressed at the same time. Simply blaming bush meat, which has been consumed since the start of human history, does not address the key issue — biodiversity loss.
The extent tropical forests has been halved in the past century. When animals at the top of the food chain disappear, those at the bottom, such as rats and mice that normally carry more pathogens, take up the space.
Habitat loss forces animals and their diseases to go elsewhere. Species in degraded ecosystems carry more disease.
Natural animal habitats are being destroyed for monocultural agricultural production by corporations — soy, corn and palm oil — and for logging, mining, roads and urbanisation. The consequences of this practice are not factored into the extracted profits.
Climate change is another factor. As climatic zones are altered wildlife migrates to new areas and interacts with species it never did before, passing on its diseases.
COVID-19 has a low mortality rate — about 1% — but is highly infectious.
The Ebola mortality rate is 90%, but infection does not spread easily. A new disease with the mortality rate of Ebola and the infection rate of COVID-19, or the flu, would be far more devastating than either alone.
If the world continues to allow the unrestricted greed of profit to destroy the world’s natural and agricultural ecosystems, such an outcome becomes more likely. We live in a world where profits are privatised, but the ecological consequences are paid for by everybody.
Indian agroecologist Vandana Shiva says that the profit motive separates humans from the ecosystems that life, including us, depends on: “As forests are destroyed, as our farms become industrial monocultures to produce toxic, nutritionally empty commodities, and our diets become degraded through industrial processing with synthetic chemicals and genetic engineering in labs, we become connected through disease.”
COVID-19 was predicted, and inevitable, because of how nature is treated. As well as treating the epidemic, and preparing for the next one, we have to address the root cause, restoring the broken link between humans and the environment.