Paris:
Scientists have found a further clue to the origins of the virus that causes Covid-19, with bats living in caves in Laos located to be carrying a related pathogen that professionals recommend could potentially infect humans straight.
The virus has killed millions considering that it emerged in China in late 2019, and controversy continues to swirl about exactly where it came from.
Some professionals say it is animal-driven but other individuals have pointed to the possibility the pathogen leaked from a lab.
Researchers from France’s Pasteur Institute and the National University of Laos mentioned their findings showed that viruses genetically close to the SARS-CoV-2 virus “exist in nature” amongst bat species in the limestone caves of northern Laos, which neighbours China.
Of the viruses they identified amongst the hundreds of bats tested in Vientiane Province, 3 had been located to closely resemble the virus that causes Covid-19, especially in the mechanism for latching on to human cells.
“The idea was to try to identify the origin of this pandemic,” Marc Eloit, who leads the Pasteur Institute’s pathogen discovery laboratory, told AFP.
Eloit, whose group analysed the samples collected, mentioned there had been nonetheless crucial variations involving the viruses located and SARS-CoV-2.
But he mentioned the work was “a major step forward” in identifying the pandemic’s origin, confirming the theory that the coronavirus that has spread across the world could have began with living bats.
The authors of the study, which has been submitted to Nature for peer overview, warned that their findings recommend the new viruses “seem to have the same potential for infecting humans as early strains of SARS-CoV-2”.
“People working in caves, such as guano collectors, or certain ascetic religious communities who spend time in or very close to caves, as well as tourists who visit the caves, are particularly at risk of being exposed,” the authors mentioned.
‘Natural spillover’
International professionals sent to China by the World Health Organization (WHO) in January concluded that it was most most likely that the SARS-CoV-2 virus jumped from bats to humans through an intermediate animal.
A competing hypothesis that the virus leaked from a lab like the specialised virology laboratory in Wuhan was deemed “extremely unlikely”, despite the fact that it has but to be ruled out.
Martin Hibbert, Professor of Emerging Infectious Disease at the London School of Hygiene and Tropical Medicine — who was not involved in the Laos study — mentioned the most closely associated virus was located to be capable to infect human cells “as easily” as SARS-CoV-2 and for that reason could possibly be capable of infecting humans.
But he stressed that the virus is “not an ancestor of the pandemic strain”.
“This work confirms the expected diverse nature of bat infecting coronaviruses and increases the evidence that natural spill-over events from bats to humans can occur,” mentioned Hibbert.
The authors of the Laos study, which has been posted on the web-site Research Square, mentioned their outcomes recommend the pandemic coronavirus potentially evolved by means of mixing involving various viruses and species of bats.
James Wood, Head of Department of Veterinary Medicine at University of Cambridge — who was also not involved in the study — mentioned it suggests “recombination between different viruses was likely involved, rather than there being a simple evolution of a single lineage over a long period”.
In a comment to the Science Media Centre he mentioned this not only underscores the most likely function played by bats and maybe other animals living closely collectively, but also shows the “risks inherent in living wildlife trade”, exactly where markets can assistance drive cross-species zoonotic transmission.
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