The origin of the SARS-CoV-2 virus that triggered the COVID-19 pandemic has been a heated topic of discussion.
The Shift Of Coronavirus From Animals To Humans
This issue has strained America-China relations, with China viewing Foreign Minister Marise Payne’s request for a new investigation into the dispute’s origins as a hostile move.
What is undeniable is that bats are the virus’s closest cousins. The question is how, where, and when the virus made its way into people. One commonly accepted theory is that the overflow happened at Wuhan’s “wet markets,” where numerous kinds of animals from across the nation are kept in cramped settings.
However, there is no indication that the bat species that carry the closest relatives of SARS-CoV-2 were sold via the Wuhan wet markets in the two years leading up to the epidemic. This theory necessitates the presence of a “bridge host,” a species that becomes sick as a result of viral overflow from the initial bat hosts and then transmits the virus to humans.
There are many experts across the world that has increased the doubt of moving the virus from animals to humans. These proofs have again raised the theory of the spread of the virus from bats and other animals to humans, which is repeatedly asked by the experts from China and rejected with such claims by various virologists all over the world. Once again, after such research, the debate of movement of the virus from one species to another over a period.
In many developing human illnesses, bridge hosts are well-known. Flying foxes, for example, are the reservoir for the Hendra virus, which my lab investigates. Hendra has a habit of spilling over into the world of horses. Horses then act as a bridge host, amplifying the virus and allowing it to infect people. Fortunately, this is a very rare occurrence, with just seven examples recorded. Four of the folks tragically perished. Hendra has never been directly transmitted from flying foxes to people.
The genesis of the pandemic was the consequence of a “lab leak,” according to a second, far more controversial explanation. Wuhan is home to one of China’s most advanced virological facilities, which specializes in bat viruses. According to the theory, one of the staff may have accidentally transmitted the virus to the broader public. This idea has no concrete evidence to back it up. A new pre-print research published online this month offers compelling evidence for the “natural spillover” theory, with findings that are difficult to reconcile with the “lab leak” idea.
The researchers retrieved all of SARS-full CoV-2’s genetic sequences from a widely utilized genomic database. There were 369 lineages A sequences, 1,297 lineage B sequences, and just 38 intermediate sequences. Genetic sequencing is a complex procedure and has flaws.
Close inspection of the 38 intermediates revealed that they were more likely to be pure lineage A or lineage B sequencing mistakes than real intermediates. As a result, the genetic data strongly implies that at least two distinct spillover episodes into human populations have occurred.
The data does not indicate that just two spillover occurrences occurred; there might have been more. They also don’t say if the spillovers were caused directly by bats or if an intermediary bridge host
caused some or all of them.
According to a Nature news story, this data refers to the spillover occurring through the wildlife trade, but I believe this is going too far.
While some wildlife species sold at the Wuhan wet market can get infected with SARS-CoV-2 (such as raccoon dogs and mink), there is no indication that any of the animals sold there were sick.
