March 26, 2020 -- Coronaviruses similar to the pandemic-causing SARS-CoV-2 coronavirus have been found in pangolins that were smuggled into China, researchers report.
Evidence suggests that bats may be the likely reservoir for SARS-CoV-2, but intermediate host animals that could have led to the transfer of this virus into humans remain unknown.
Pangolins are considered a possible intermediate host animal because they're the most widely illegally trafficked mammal -- for use as food and in Eastern medicine -- and are the only mammals other than bats found to be infected with a SARS-CoV-2-related coronavirus.
Researchers analyzed samples from 18 Malayan pangolins seized by anti-smuggling officials in southern China between August 2017 and January 2018. SARS-CoV-2-related coronaviruses were detected in five of the pangolins.
Similar coronaviruses were found in three of 12 more pangolins seized in a second Chinese province in 2018 and in another pangolin from a third province.
However, all of the coronaviruses found in the pangolins lack a specific feature seen in human SARS-CoV-2, which makes pangolin's role in the transmission of the coronavirus into humans unclear, according to the authors of the study published March 26 in the journal Nature.
The degree of similarity between coronaviruses in pangolins and the SARS-CoV-2 coronavirus isn't sufficient to suggest that pangolins are intermediate hosts directly involved in the coronavirus pandemic.
However, these findings suggest that pangolins are a second mammalian host of coronaviruses and that their sale in wildlife markets should be banned to reduce the risk of future virus transmission to humans, the researchers said.