First Covid-19 case could have hit China in October 2019: Study – News Vibe24

    First Covid-19 case could have hit China in October 2019: Study - Times of India
    SHANGHAI: The virus that causes Covid-19 could have started spreading in China as early as October 2019, two months before the first case was identified in the central city of Wuhan, according to a new study on Friday.
    Researchers at the University of Kent in the UK have used conservation science methods to estimate that SARS-CoV-2 first appeared between early October and mid-November 2019, according to a paper published in the journal PLOS Pathogens.
    The most probable date for the appearance of the virus was November 17, 2019 and most likely it had already spread worldwide by January 2020.
    China’s first official Covid-19 case was in December 2019 and was linked to Wuhan Huanan seafood market.
    However, some of the first cases were not known to Huanan, which means that SARS-CoV-2 was already released before it hit the market.
    A joint study published by China and the World Health Organization in late March acknowledged that there could be sporadic human infections before the Wuhan outbreak.
    In a print newspaper this week, Jesse Bloom of the Fred Hutchinson Cancer Research Center in Seattle recovered deleted sequence data from the first cases of Covid-19 in China.
    The data showed that samples taken from the Juan market were not “representative” of SARS-CoV-2 as a whole and were a variant of an earlier ancestral sequence that spread to other parts of China.
    The US National Institutes of Health confirmed to Reuters that the samples used in the study were submitted to the Reading Sequence Archive (SRA) in March 2020 and later deleted at the request of Chinese researchers, who said they would be informed and submitted to another archive.
    Critics say the deletion was further evidence that China was trying to cover the origin of Covid-19.
    “Why do scientists ask international databases to delete key data that tells us how Covid-19 started in Wuhan?” said Alina Chan, a researcher at Harvard’s Broad Institute, writing on Twitter.
    Another study by Australian scientists, published Thursday in the scientific journal Scientific Reports, used genomic data to show that SARS-CoV-2 binds to human receptors much more easily than other species, suggesting that it had already adapted to humans when it appeared. for the first time.
    He said there may have been another unknown animal with an even stronger affinity that served as an intermediate species, but it could not be ruled out that it leaked from the laboratory.
    “While it is clear that early viruses were highly susceptible to human receptors, this does not mean that they were ‘anthropogenic,'” said Dominic Dwyer, an infectious disease specialist at Westmead Hospital in Australia, who was part of the WHO team. researching Covid 19 in Wuhan this year.
    “Such conclusions remain speculative,” he said.
    Serum samples still needed to be tested to make a stronger case for the origin of Covid-19, said Stuart Turville, an associate professor at the Kirby Institute, an Australian medical research organization that responded to a University of Kent study.
    “Unfortunately with the current pressure of the laboratory leak case and the sensitivities involved in conducting this surveillance investigation in China, it may take some time to see such reports,” he said.


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