There are several claims related to the source of the new Coronavirus as countries like Italy, US and China are facing a nightmare after the COVID-19 outbreak in December 2019. But recently world's top scientists revealed that the Coronavirus have been quietly spreading among humans decades before the recent outbreak in China's Wuhan.
An investigation was conducted by US, UK and Australia based scientists who looked into data released by other scientists from all around the world to understand the deadly Coronavirus. Their investigation revealed that the virus might have made the jump from animal to humans long before the first detection in the city Wuhan.
It should be mentioned that the study was conducted by recently tested positive, Ian Lipkin from Columbia University in New York, worked as a 'Contagion' movie's chief consultant and Kristian Andersen from the Scripps Research Institute in California, Andrew Rambaut from the University of Edinburgh in Scotland and Edward Holmes from the University of Sydney and Robert Garry from Tulane University in New Orleans. The study was published in the scientific journal Nature Medicine.
Coronavirus outbreak in China
Doctors in Wuhan began noticing a surge in the number of people suffering from a mysterious pneumonia-like virus since December first week. Even though they tried to alert the Wuhan authorities about the unknown disease, they also tried to silence these doctors.
While tests for flu and other pathogens returned negative after patients got admitted in Wuhan hospital, an unknown strain was isolated. A team of researchers from the Wuhan Institute of Virology led by Shi Zhengli traced its origin to a virus found in bats from a mountain cave close to the China-Myanmar border. But it was revealed that the bat virus could not infect humans.
Later, scientists from Guangzhou and Hong Kong found Coronaviruses with a similar spike protein in Malayan pangolins that led to believe that teams recombination of genomes had occurred between the pangolin and bat viruses.
The New Coronavirus
However, the SARS-Cov-2, called as Novel Coronavirus had a mutation in its genes known as a polybasic cleavage site that was not found in other Coronaviruses in bats and pangolins, said Andersen.
Separate studies from China, France and US claimed that the mutation could produce a unique structure in the virus' spike protein to interact with furin, which is a widely distributed enzyme in the human body. It could then trigger fusion of the viral envelope and human cell membrane after coming into contact with each other.
As per the scientist, SARS and MERS have direct descendants of species found in masked civets and camels, which had a 99 per cent genetic similarity. But for Novel Coronavirus, there is no such direct evidence, as per the international team of researchers. Anderson further said, "It is possible that a progenitor of SARS-CoV-2 jumped into humans, acquiring the genomic features described above through adaptation during undetected human-to-human transmission. Once acquired, these adaptations would enable the pandemic to take off and produce a sufficiently large cluster of cases to trigger the surveillance system that detected it."
As per Zhong Nanshan, who advises China on outbreak containment policies, said there was growing scientific evidence to suggest the origin of the virus might not have been in China. An unnamed doctor from Beijing who is working in a public hospital and regularly checking Covid-19 patients mentioned numerous cases of mysterious pneumonia outbreaks were reported by health officials in several countries in 2019. He said re-examination of these cases from last year could reveal more clues about the history of this Coronavirus pandemic.