Scientists find 'very likely' source of Covid-19 pandemic

A team of scientists painstakingly analysed hundreds of genetic samples to find what they believe was the source of the pandemic

Scientists believe they may have cracked the mystery of where the virus that caused the Covid-19 pandemic originated. The world came to a standstill, lockdowns were enforced and city streets turned into ghost towns as the SARS-CoV-2 virus spread like wildfire in late 2019.

The World Health Organisation reckons around 3 million people died in 2020 alone due to the virus, but the source of the outbreak has been a bone of contention. The most widely accepted theory is that it sprung from a wet market in Wuhan, China.

However, other theories have ranged from a leak at the nearby Wuhan Institute of Virology, to it being deliberately spread by another country. But now, an elite team of scientists say that, through genetic analysis, they have identified a shortlist of wild animals sold at the Huanan seafood market in Wuhan that were the most likely source of the virus.

While bats are thought to have been the original carrier of the SARS-CoV-2 virus, others believe that an intermediate wild species got infected and brought it to the market, leading to an outbreak. Stalls there sold live animals as well as seafood, according to New Scientist.

The international team of researchers reckon the virus probably emerged from wild animals sold at the market. They re-analysed data from 800 samples collected at the market by the Chinese Centre for Disease Control and Prevention starting on January 1, 2020, and also studied viral genomes from the earliest Covid-19 cases.

Ed Holmes, from the University of Sydney team said: "We analysed these data to determine which species were present and where they were found in the market, particularly in relation to where SARS-CoV-2 was found."

The team discovered signs of various wildlife being traded at the market, potentially serving as intermediate hosts for the virus, including raccoon dogs, palm civets, and bamboo rats, located at the same stalls where the virus was detected. "This suggests but does not prove that the animals were infected. Hence, it is very likely that SARS-CoV-2 emerged in a live animal market," Holmes added, asserting that the scientific evidence predominantly supports the natural zoonotic origin of the virus at the Huanan market in Wuhan.

Nevertheless, the investigation also acknowledges that they cannot disregard the possibility of the virus being introduced to the market by an already infected person handling the animals.