In what appears to be a spin to the truth behind the origin of the novel coronavirus in Wuhan, Chinese scientists are now claiming through their research that it is the Indian subcontinent might be the place where the earliest human-to-human transmission of SARS-Cov-2 transmission occurred between July 2019 and August 2019, three months prior to the Wuhan outbreak.
The research paper titled The Early Cryptic Transmission and Evolution of SARS-CoV-2 in Human Hosts’ by Chinese scientists Libing Shen of Chinese Academy of Sciences (CAS) – Institute of Neuroscience, Funan He of Fudan University – School of Life Sciences, and Zhao Zhang of the University of Texas at Houston – Department of Biochemistry and Molecular Biology which featured in the Preprints in The Lancet opined that the strain diversity suggests that the Indian subcontinent might be the place where the earliest human-to-human SARS-CoV-2 transmission occurred, which was three or four months prior to the Wuhan outbreak.
“According to their coding region identity, we classified 4571 SARS-CoV-2 genome sequences into 2449 viral strains collected from human hosts between December 2019 and July 2020. We found that the SARS-CoV-2 (NC_045512) strain first identified in Wuhan is not the least mutated strain.
There are 41 SARS-CoV-2 strains harboring fewer global point mutations than the NC_045512 strain in our dataset. The least mutated strain can be found in eight countries across four continents due to SARS-CoV-2’s low mutability. Eight positive selection sites are identified in five SARS-CoV-2’s genes and four of them were present in the early stage of SARS-CoV-2’s human-to-human transmission.
The NC_045512 strain has two positive selection sites, one in RNA-dependent RNA polymerase (L314P) and the other in spike protein (G614D). The statistical analysis of the SARS-CoV-2’s strain diversity in different countries/regions shows that the Indian subcontinent has the highest strain diversity. Furthermore, based on the SARS-CoV-2’s mutation rate, we estimate that the earliest SARS-CoV-2 transmission in human hosts could be traced back to July or August of 2019.
Our result shows that Wuhan is not the place where human-to-human SARS-CoV-2 transmission first happened. Before it spread to Wuhan, SARS-CoV-2 has already experienced adaptive evolution during its human-to-human transmission.
The positive selection sites could contribute to the different clinical features of different SARS-CoV-2 strains. Both the least mutated strain’s geographic information and the strain diversity suggest that the Indian subcontinent might be the place where the earliest human-to-human SARS-CoV-2 transmission occurred, which was three or four months prior to the Wuhan outbreak.
Our study helps to elucidate the early cryptic transmission and evolution of SARS-CoV-2 in human hosts and provide new thinking for the global management of the COVID-19 pandemic.”
The number of global novel coronavirus cases has surpassed the 62 million mark, while the deaths have surged to more than 1.45 million, the Johns Hopkins University said on Sunday. The University’s Center for Systems Science and Engineering (CSSE) revealed that the current global caseload and death toll stood at 62,147,874 and 1,450,326, respectively.
SSRN
