Four Possible Pathways:
Direct zoonotic spillover is possible to likely
COVID-19 introduction through an intermediate host is likely to very likely
Introduction through cold/food chain products is possible Introduction through a laboratory incident is extremely unlikely
No evidence shows that respiratory illness before the COVID-19 outbreak was affected by SARS-CoV-2.
It is considered unlikely that any substantial transmission of SARS-CoV-2 infection was occurring in Wuhan during October-November 2019.
There is no firm conclusion about the role of the Huanan market in the origin of the outbreak.
Early Transmission in Other Countries
Bats and pangolins may be the reservoir of the virus that causes COVID-19. However, neither of the viruses identified so far from these mammalian species is sufficiently similar to SARS-CoV-2 to serve as its direct progenitor.
The high susceptibility of mink and cats to SARS-CoV-2 suggests that additional species of animals may act as a potential reservoir.
The Role of Cold Chain Remains Unclear
The animal and environment working group found no SARS-CoV-2 in samples and surveillance for wild animal disease in China.
SARS-CoV-2 has been found to persist in conditions found in frozen food, packaging and cold-chain products.
The joint international team made the following recommendations:
1. Develop a comprehensive information database to combine molecular data, global distribution data and other metadata of potential animal hosts.
2. Conduct further retrospective and systematic research around earlier cases and possible hosts for SARS-CoV-2 around the world.
3. Analyse the role of cold chain and frozen food in the possible introduction of the virus
Full Text: http://www.bjreview.com/Documents/202108/U020210826395616640542.pdf