UPDATE 30 March 2020: A paper published in the journal Nature on March 26 shows further evidence that pangolins can carry coronaviruses similar to the latest strain that has resulted in the COVID-19 outbreak. While this research does not prove or disprove that pangolins are the intermediate hosts of SARS-CoV-2 the study does show that the scaly anteaters may play a role in the spread of new coronaviruses.

Elsewhere coverage referenced a new paper by four Chinese researchers that used genome analysis of SARS-CoV-2 to propose that the virus “recombined” in a pangolin before being transferred to humans.

Reports emerged Friday (February 7, 2020) linking the latest deadly strain of coronavirus to pangolins captured for the wildlife trade. Although few details were provided, researchers from the South China Agricultural University suggested at a press conference that pangolins could potentially be intermediate hosts for the new epidemic. After drawing data from 1,000 samples they found that – in 70% of the cases analysed – the strain of coronavirus detected was 99% identical to that found in infected humans.

Pangolins are widely considered to be the most trafficked mammals on earth.

The Daily Maverick offers further insights, tracing the origins of the claim to researchers working with the Baylor College of Medicine in Texas who conducted research into the viral communities of Malayan Pangolins (Manis javanica) last year.

Although it is yet to be proven, bats are believed to be the primary carriers of the latest strain of coronavirus (known as nCoV-2019). The Baylor team believe that the virus may have “recombined” in a pangolin before being transferred to humans.

Pangolins are considered one of Asia's most trafficked mammals. The scaly anteaters are sought after for their meat, which is eaten as a delicacy in countries such as China; and their scales, which are used in traditional medicine. "This latest discovery will be of great significance for the prevention and control of the origin (of the virus)," South China Agricultural University stated.

The coronavirus outbreak, which has claimed the lives of over 3,304 people* in mainland China, is thought to have originated at a market selling live animals in the city of Wuhan. Some Chinese "wet markets" (as they are sometimes called) present ideal breeding grounds for viruses. Animals are kept in small enclosures in close proximity to one another allowing for the spread of pathogens through fluid exchange or aerosolisation. This can lead to a zoonotic spillover, or a “jump” of the virus from non-human animals to humans. China has since issued a ban on the trade in wild animal products for food, but there is still some debate over their use in traditional medicines.**

A controversial study published earlier this year claimed that snakes could be the intermediate hosts, but the hypothesis was widely refuted, raising questions over the latest claims involving pangolins.

So are scaly anteaters responsible for fuelling an epidemic? 

According to Professor Matthew C. Wong, a computer scientist working at the Baylor department of molecular virology and microbiology, it is highly possible. Wong scanned existing genomic data of coronaviruses derived from animals that are known to be in China. His goal was to find a strain of the virus that matched the current pandemic. His most significant result came from a pangolin. Wong tracked down a “genome of a coronavirus whose receptor gene matched the pandemic strain nearly 100% — pointing to the likelihood that the bat virus and pangolin virus at some point were in the same animal and had the chance to share genetic material … leading to the hybridisation [recombination] event that resulted in the pandemic strain," The Daily Maverick explains.

It remains to be determined if there are other animals involved or the order in which the recombination event took place. Given the complexity of viral outbreaks and the trickiness of determining their origins, many researchers were cautious to draw definitive conclusions following the recent announcement.

"The evidence for the potential involvement of pangolins in the outbreak has not been published, other than by a university press release," says Professor James Wood who heads up the Department of Veterinary Medicine at the University of Cambridge. "This is not scientific evidence; investigations into animal reservoirs are extremely important, but results must then be published for international scrutiny to allow proper consideration."

Jonathan Ball, a professor of molecular virology at the University of Nottingham was also hesitant to draw conclusions: "This is a very interesting development – the potential source of the novel coronavirus has been a key unknown. Whether or not the endangered pangolin really is the reservoir is still unclear. We would need to see all of the genetic data to get a feel for how related the human and pangolin viruses are, and also gain an understanding of how prevalent this virus is in pangolins and whether or not these were being sold in the Wuhan wet markets."

National Geographic senior editor and investigative reporter Rachael Bale was quick to create a Twitter thread warning the public not to jump to conclusions:

Header image: Esther Simpson/Flickr

*This figure was last updated on March 30, 2020.

**This article originally referred to a temporary ban issued by China on January 22. This ban has since been made permanent. The article was amended for accuracy.