Pangolins confiscated from the illegal wildlife trade in Vietnam have been found to host Covid-like viruses, providing further evidence of the pandemic risk associated with the international trade in wild animals.
Analysis documented in the journal Frontiers in Public Health found that coronaviruses related to the severe acute respiratory syndrome coronavirus 2 (SARS CoV 2) identified in the pangolins in Vietnam — which is a major global hub for the illegal wildlife trade — were closely related to those previously only detected in pangolins retrieved from the illegal wildlife trade in China.
The ongoing SARS-CoV-2, or Covid-19 pandemic, is believed to have originated in a wet market in Wuhan, China where exotic wild mammals were being traded — a theory that has recently gained credibility over rival origination theories, such as a leak from a Wuhan laboratory that engineered the virus. A study published in February found that the outbreak “very likely” resulted from at least two incidences of the disease passing from animals to humans at the Huanan Seafood Wholesale Market in Wuhan.
The authors of the new study, which was led by scientists from Wildlife Conservation Society (WCS), said that the discovery of SARS-CoV-2-like viruses in Sunda pangolins in Vietnam is evidence that the transnational nature of the wildlife trade can help dangerous diseases spread and amplify along the trade chain.
Pangolins are among the mammals suspected of initially passing SARS-CoV-2 to people, along with bats, ferrets, and racoon dogs.
The authors of the study tested specimens from 246 pangolin confiscations from the wildlife trade in Vietnam between 2016 and 2018. They found that seven individuals tested positive for a SARS-CoV-2-related virus.
WCS Vietnam programme officer Nguyen Thi Thanh Nga said: “This study confirms the presence of coronaviruses in the SARS-CoV family in trafficked pangolins in Vietnam. Eliminating the trade in pangolins and other wild mammals and birds will eliminate this high-risk pathway for viral spillover and pathogen emergence.”
Pangolins are the world’s most trafficked mammals. All four species of Asian pangolins, including the Sunda and Chinese pangolin, are endangered or critically endangered. All eight species are listed on the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix I, which bans all international trade for commercial purposes.
The pangolin confiscations sampled in the Vietnam study involved other live wildlife, including a mix of primates, reptiles, and birds. The report’s authors said their findings support long-held concerns that the live wildlife trade poses a “serious and increasing risk” of starting epidemics of novel and emerging pathogens in human populations. Stressed live animals moved out of their natural habitats are more likely to express the diseases that they carry and pass them on to people.
In April last year, the World Health Organisation, along with United Nations Environmental Programme, called on governments to suspend the trade in live caught wild mammals for food or breeding, and close markets selling wildlife, “unless demonstrable effective regulations and adequate risk assessments are in place.”
The report’s authors said these recommendations are “too narrowly focused” on markets and fail to address the full wildlife supply chain. Wildlife trade policy reform is needed to reduce the risk of future pandemics and prevention measures must consider that the wildlife trade may spread new viruses, which cannot be detected with current sample screening practices or procedures, the authors said.
Since the Covid-19 outbreak at the end of 2019, China has cracked down on the illegal wildlife trade and initiated legislative reforms to phase out the wildlife trade, although reports suggest that these measures have not been effectively enforced and much of the trade has moved online.
Vietnam banned wildlife imports in January 2020 after pressure from conservation groups.
