Viruses similar to the pathogen fuelling the current global pandemic have been found in trafficked pangolins, as scientists warned that the scaly mammal needs to be banned from animal markets to prevent another coronavirus outbreak in the future.
A study from the University of Sydney has shown that Sars-CoV-2, the virus that causes Covid-19, bears genetic similarities to a different strain of coronavirus currently infecting the Malayan pangolin population of southern China.
The research, published in the journal Nature, warns that “handling these animals requires considerable caution”.
Professor Edward Holmes, an evolutionary virologist who led the study, said: “The role that pangolins play in the emergence of Sars-CoV-2 is still unclear. However, it is striking that the pangolin viruses contain some genomic regions that are very closely related to the human virus.
“The most important of these is the receptor-binding domain that dictates how the virus is able to attach and infect human cells.”
Since the emergence of Covid-19 in Wuhan last year, the pangolin has been identified as a potential host for the virus before its transmission to humans – something that Mr Holmes’s research said was a possibility.
Bats have also been identified as a possible source of the pathogen, having previously been responsible for the Sars outbreak that spread across China between 2002 and 2003.
Professor Holmes added: “It is clear that wildlife contains many coronaviruses that could potentially emerge in humans in the future. A crucial lesson from this pandemic to help prevent the next one is that humans must reduce their exposure to wildlife, for example by banning ‘wet markets’ and the trade in wildlife.”
As one of the most widely trafficked mammals in the world, the pangolin is currently threatened with extinction. Its scales are used in traditional Chinese medicine, while the animal’s meat is considered a delicacy in parts of Asia.
Professor Holmes’s paper, which has since become the most shared study among academics of all time, also dispels the theory that Sars-CoV-2 was designed and manufactured in a laboratory.
“There is simply no evidence that Sars-CoV-2 – the cause of Covid-19 – came out of a lab,” he said. “In reality, this is the sort of natural disease emergence event that researchers in the field like myself have been warning about for many years.”
In separate research conducted by Professor Holmes and scientists in Shanghai, genetic links have been confirmed between samples taken from the Wuhan wet market, the alleged origin of the global pandemic, and the city’s earliest Covid-19 patients.
However, researchers warned that as “not all of the early [Covid-19] cases were market associated, it is possible that the emergence story is more complicated than first suspected”.