No Evidence of Coronaviruses or Other Potentially Zoonotic Viruses in Sunda pangolins (Manis javanica) Entering the Wildlife Trade via Malaysia

Abstract

The legal and illegal trade in wildlife for food, medicine and other products is a globally significant threat to biodiversity that is also responsible for the emergence of pathogens that threaten human and livestock health and our global economy. Trade in wildlife likely played a role in the origin of COVID-19, and viruses closely related to SARS-CoV-2 have been identified in bats and pangolins, both traded widely. To investigate the possible role of pangolins as a source of potential zoonoses, we collected throat and rectal swabs from 334 Sunda pangolins (Manis javanica) confiscated in Peninsular Malaysia and Sabah between August 2009 and March 2019. Total nucleic acid was extracted for viral molecular screening using conventional PCR protocols used to routinely identify known and novel viruses in extensive prior sampling (> 50,000 mammals). No sample yielded a positive PCR result for any of the targeted viral families—Coronaviridae, Filoviridae, Flaviviridae, Orthomyxoviridae and Paramyxoviridae. In the light of recent reports of coronaviruses including a SARS-CoV-2-related virus in Sunda pangolins in China, the lack of any coronavirus detection in our ‘upstream’ market chain samples suggests that these detections in ‘downstream’ animals more plausibly reflect exposure to infected humans, wildlife or other animals within the wildlife trade network. While confirmatory serologic studies are needed, it is likely that Sunda pangolins are incidental hosts of coronaviruses. Our findings further support the importance of ending the trade in wildlife globally.

Exploring the natural origins of SARS-CoV-2 in the light of recombination

“…The most common routes involve moving the animals from Southeast Asia (Myanmar, Malaysia, Laos, Indonesia, Vietnam) to Guangxi, Guangdong, and Yunnan. The most likely scenario is that these Sarbecoviruses infected the pangolins after being trafficked into Southern China, consistent with the respiratory distress they exhibit (Liu et al 2019 ;Xiao et al 2020) and the lack of evidence of infection of Sunda pangolins in Malaysia (Lee et al 2020) .…”

TheRhinolophus affinisbat ACE2 and multiple animal orthologs are functional receptors for bat coronavirus RaTG13 and SARS-CoV-2

“…Moreover, pangolins are solitary animals, and infection by these pangolin CoVs is lethal for most pangolins 9 , suggesting that these pangolin CoVs might not be native to pangolins. Recent studies on 334 Sunda pangolins did not find any CoVs or other potential zoonotic viruses in these animals 38 , further supporting that pangolins might not be reservoir hosts for these pangolin CoVs. Where, when, and how these pangolins acquired these CoVs remain elusive.…”

SARS-CoV-2 and Zoonotic Preparedness: Unknown Knowns?

“…14 A recent study on wild or recently captured Malayan pangolins has shown no presence of CoVs. 15 Palm civets infected with SARS-CoV 16 similarly showed signs of illness and respiratory distress, suggestive as a role as an intermediate host but unlikely to be a natural reservoir.…”