Chinese scientists ‘found closest relative of coronavirus seven years ago’
Scientists found a deadly coronavirus 96 per cent similar to the one that causes Covid-19 in an abandoned mine in China seven years ago, a new investigation claims.
The mine, hundreds of miles away from Wuhan, came to the attention of disease researchers after six men tasked with clearing bat faeces from the mine fell ill with a mysterious illness, of whom three died.
Their symptoms – including high fever, aching limbs and breathing difficulties – puzzled doctors until an expert suggested they might be suffering from a different coronavirus related to the strain behind the 2002-2004 Sars outbreak.
Frozen samples taken to the Wuhan Institute of Virology contained the same strain which scientists from the lab would later reveal as the closest known relative of the coronavirus sweeping the world today, according to The Sunday Times.
Shi Zengli, the head of the institute’s Center for Emerging Infectious Diseases nicknamed ‘Bat Woman’ because of her virus-hunting trips to bat caves in the last 16 years, told Scientific American in June that the mine workers had been killed by a deadly fungus.
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But details of their treatment were found by the Times in papers written by a junior doctor working in the hospital that admitted them and a PhD student working in the Chinese Centre for Disease Control and Prevention.
They did not confirm the exact cause of death but suggested the most likely cause was a Sars-like coronavirus from a bat.
Two of the men had died quickly while the remaining four were taken in for tests, including antibody tests for coronaviruses.
The two who recovered and had higher levels of antibodies than those kept in hospital, of whom one more died.
The mine sample, named RaTG13, was described in a paper published in the Nature scientific journal on February 3 which also revealed the full genetic makeup of the Covid-19 virus.
The study said their close similarity ‘provides evidence’ that the Covid virus ‘may have originated in bats’ and was considered groundbreaking.
Yet the only detail on where the sample came from was that it was taken from a ‘Rhinolophus affinis’ bat in Yunnan province in 2013.
A paper had been published in 2016 on the strain found in the mine along with several others found in the bat colonies living there, but the sample was named as RaBtCoV/4991.
A database of bat viruses published by the Chinese Academy of Sciences, which oversees the Wuhan Institute of Virology, lists them as one and the same, according to the Times, and the two have also been matched by scientists in India and Austria.
Peter Daszak, an animal disease expert who has helped the Wuhan Institute track viruses for 15 years, confirmed the match but said there was nothing sinister about the renaming.
He told the newspaper: ‘The conspiracy folks are saying there’s something suspicious about the change in name, but the world has changed in six years — the coding system has changed’.
But other scientists interviewed for the report questioned the lack of further investigation into RaTG13 as highly unusual given the deaths of three of the six miners who came into contact with it.
Wendy Barclay, a professor leading Imperial College’s infectious disease department who sits on the government’s Sage advisory committee, said: ‘I would expect people to be as clear as they can be about the history of the isolates of their sequencing.
‘Most of us would have reported the entire history of the isolate, [back] to where all that came from, at the time.’
Meanwhile, NewScientist has drawn attention to a 2016 paper on RaTG13 by Harvard Medical School warning the virus could replicate in human airway cells and was ‘poised for human emergence’.
The researchers said further study of the virus was hindered by the US government’s ban on any work that alters viruses in a way that could make them more dangerous.
China does not have a similar ban. Work by Ms Shi’s team between 2015 and 2017 has been described as experiments on coronaviruses to see if they could be made more transmissible.
Experts disagree on whether RaTG13 could have mutated into the Covid-19 virus in just a few years, even with tinkering by scientists.
Meanwhile Ms Shi’s team has defended the work as important to understanding how ordinary coronaviruses can turn into deadlier strains.
It’s believed a number of academics have written to Nature asking for the Wuhan Institute to clarify where the sample came from but the lab has kept quiet.
The institute has not commented on any reports questioning the sample’s origins.
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