Coronavirus could have spread to humans from bats via pangolins

By Dr. Ananya Mandal, MDFeb 10 2020

A new research from China reveals that the novel corona virus that has killed hundreds of infected persons in Wuhan from the Hubei province in China and infected thousands across the world could have spread to humans via bats mediated via another species of animals – pangolins.

Pangolins from smuggling are secured at the Natural Resources Conservation Center Riau, Pekanbaru, Indonesia, Wednesday. Image Credit: Arief Budi Kusuma / Shutterstock

Researchers noted that pangolins are one of the most illegally trafficked animals in Asia mainly because these are the only species of scaled mammals. These mammals are trafficked for food as well as for the medicinal properties of their scales using in traditional Chinese medicine. Their poaching and trading is controlled by the international law says the World Wildlife Fund, but sales remain undaunted under cover in Asia and Africa. There has been a ban on trade and sale of pangolins since 2016 and their survival is at risk says the International Union for the Conservation of Nature (IUCN) due to their high demands. These pangolins especially the Malayan pangolins are critically endangered and belong to the IUCN Red List of Threatened Species.

South China Agricultural University, in a statement on their website said, “This latest discovery will be of great significance for the prevention and control of the origin (of the virus).” The researchers working on this new finding were working on this project at this institute in collaboration with a team of scientists at the Baylor College of Medicine in Houston, Texas. Till date nearly 900 individuals are known to have been killed by the novel corona virus. The virus first was reported on the 31st of December 2019 and since then investigations have traced back its origins to the exotic meat and sea food markets in China’s Wuhan. All forms of exotic meat sales have been banned since then. The researchers have been trying to figure out the source of the virus and its transmission via other animals to humans.

This new study shows that bats could be spreading the virus and this final link from bats to humans could be pangolins. For this study the team looked at the genes and genomic sequences of the novel coronavirus isolated from pangolins. These viruses were 99 percent similar to the virus samples obtained from the infected individuals said the researchers. This makes it most likely the pangolins are the “intermediate host” say researchers. Twenty one Malayan pangolins (Manis javanica) studied at the wildlife rescue centre in China’s Guangdong province have very similar viral genomic picture compared to persons infected with the nCoV-2019 or novel corona virus, wrote the researchers.

As of now the experts warn that it is too early to draw firm conclusions because mush is unknown about the virus. Dirk Pfeiffer, professor of veterinary medicine at Hong Kong’s City University, in a statement to a news agency said, “You can only draw more definitive conclusions if you compare prevalence (of the coronavirus) between different species based on representative samples, which these almost certainly are not.”

Liu Yahong, president of the university working on the study added that it was a strong speculation that pangolins could be the intermediary host. Liu said this study could help put a stop to the illegal trafficking of the pangolins.

Dr. Ian Lipkin, an Infectious disease expert, said in a statement to a news agency that these viruses have the capacity of emerging every few years and are likely to originate and flourish in smaller mammals such as bats and get transmitted to humans vis various animal species. For example the 2003 SARS outbreak in China was caused by another strain of the corona virus and this was transmitted to humans via civet meat considered to be a Chinese delicacy. Lipkin said, “I want the wild animal markets closed.”

He is not alone in these recommendations as many markets selling exotic animal meats have been closed following the viral outbreak and the Government has since then banned such sales. The World Wildlife Fund said in a statement, “While closing wildlife markets could have a major impact, bans alone will not stop the illegal wildlife trade if demand persists. This health crisis must serve as a wake-up call for the need to end unsustainable use of endangered animals and their parts, as exotic pets, for food consumption and for their perceived medicinal value.”

Corona virus has killed large number of individuals in mainland China and at present the virus spread despite efforts has spread to other parts of the world as well. Cases of infection have been confirmed from the United States, United Kingdom, France, Germany, Australia and other countries in Asia. Over thirty thousand individuals are said to be infected. Human to human transmission has also been speculated by health agencies.