A scientist who helped conduct studies into the early stages of the coronavirus outbreak has explained how researchers traced its origins.
I’m sure I don’t need to remind anyone of the rapid spread of COVID-19 in early 2020, with reports quickly escalating from increasing cases in China to millions of positive tests across the globe.
Having been forced inside and stripped of many of our usual pastimes, some people began speculating about coronavirus, its origins, consequences and even whether it was real at all.
There were some suggestions that COVID-19 originated in a laboratory before escaping and impacting much of the human population. However, Edward C Holmes, ARC Australian Laureate Fellow and Professor at the University of Sydney, has attempted to explain how scientists traced the origins and have supposedly ruled out the ‘COVID lab leak theory’.
In studies published in the journal Science, the researchers presented their own theory that the virus came from a market in Wuhan, China.
Holmes says that the first cases of SARS-CoV-2 (COVID-19) were detected at the Huanan Seafood Wholesale Market, and analysis of the geographic locations of the earliest cases revealed a strong cluster located around this market.
He describes the market as the ‘pandemic epicentre’, explaining it is an indoor area which covers a space roughly the size of two football fields. Despite being named the ‘seafood wholesale market’, Holmes explains that a visit in 2014 showed him it was home to a ‘variety of live wildlife’, including raccoon dogs and muskrats which were for sale.
A variety of animals remained on sale at the market in 2019, and samples taken from door handles, drains and frozen animals after the market closed in January 2020 revealed a number of SARS-CoV-2 cases from the south-western corner of the market, the same corner where Holmes saw animals in 2014.
“This establishes a simple and plausible pathway for the virus to jump from animals to humans,” he says.
Holmes and his team found the first variant of COVID-19, dubbed the ‘B’ lineage, began ‘very early’ in the pandemic, with both A and B lineages being detected at the market. Analysis suggets the two different versions of the virus came from separate jumps from animals to humans, indicating there was a pool of infected animals at the market.
The B lineage was the first to jump to humans, according to analysis, followed by the A lineage. It’s unclear exactly which animals were involved in the jump, but it has been determined to have occurred no earlier than late October 2019.
Though COVID-19 did emerge in the same city that is home to the Wuhan Institute of Virology, which works on bat coronaviruses, Holmes has claimed the viruses at the lab are not related closely enough to be direct ancestors of the virus that spread across the globe.