<p>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, a new study showed on Friday.</p>.<p>Researchers from Britain's University of Kent used methods from conservation science to estimate that SARS-CoV-2 first appeared from early October to mid-November 2019, according to a paper published in the PLOS Pathogens journal.</p>.<p>The most likely date for the virus's emergence was Nov. 17, 2019, and it had probably already spread globally by January 2020, they estimated.</p>.<p>China's first official Covid-19 case was in December 2019 and was linked to Wuhan's Huanan seafood market.</p>.<p>However, some early cases had no known connection with Huanan, implying that SARS-CoV-2 was already circulating before it reached the market.</p>.<p><strong>Read | <a href="https://www.deccanherald.com/international/world-news-politics/china-disease-expert-says-covid-19-origins-probe-should-shift-to-us-998338.html" target="_blank">China disease expert says Covid-19 origins probe should shift to US</a></strong></p>.<p>A joint study published by China and the World Health Organization at the end of March acknowledged there could have been sporadic human infections before the Wuhan outbreak.</p>.<p>In a paper released this week as a preprint, Jesse Bloom of the Fred Hutchinson Cancer Research Center in Seattle recovered deleted sequencing data from the early cases of Covid-19 in China.</p>.<p>The data showed that samples taken from the Huanan market were "not representative" of SARS-CoV-2 as a whole, and were a variant of a progenitor sequence that was circulating earlier and spread to other parts of China.</p>.<p>Critics said the deletion of the data was further evidence that China was trying to cover up the origins of Covid-19.</p>.<p>"Why would scientists ask international databases to delete key data that informs us about how Covid-19 began in Wuhan?" said Alina Chan, a researcher with Harvard's Broad Institute, writing on Twitter. "That's the question you can answer for yourselves."</p>.<p>Serum samples still needed to be tested to make a stronger case about Covid-19's origins, said Stuart Turville, associate professor at the Kirby Institute, an Australian medical research organisation who was responding to the University of Kent study.</p>.<p>"Unfortunately with the current pressure of the lab leak hypothesis and the sensitivities in doing this follow-up research in China, it may be some time till we see reports like that," he said.</p>
<p>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, a new study showed on Friday.</p>.<p>Researchers from Britain's University of Kent used methods from conservation science to estimate that SARS-CoV-2 first appeared from early October to mid-November 2019, according to a paper published in the PLOS Pathogens journal.</p>.<p>The most likely date for the virus's emergence was Nov. 17, 2019, and it had probably already spread globally by January 2020, they estimated.</p>.<p>China's first official Covid-19 case was in December 2019 and was linked to Wuhan's Huanan seafood market.</p>.<p>However, some early cases had no known connection with Huanan, implying that SARS-CoV-2 was already circulating before it reached the market.</p>.<p><strong>Read | <a href="https://www.deccanherald.com/international/world-news-politics/china-disease-expert-says-covid-19-origins-probe-should-shift-to-us-998338.html" target="_blank">China disease expert says Covid-19 origins probe should shift to US</a></strong></p>.<p>A joint study published by China and the World Health Organization at the end of March acknowledged there could have been sporadic human infections before the Wuhan outbreak.</p>.<p>In a paper released this week as a preprint, Jesse Bloom of the Fred Hutchinson Cancer Research Center in Seattle recovered deleted sequencing data from the early cases of Covid-19 in China.</p>.<p>The data showed that samples taken from the Huanan market were "not representative" of SARS-CoV-2 as a whole, and were a variant of a progenitor sequence that was circulating earlier and spread to other parts of China.</p>.<p>Critics said the deletion of the data was further evidence that China was trying to cover up the origins of Covid-19.</p>.<p>"Why would scientists ask international databases to delete key data that informs us about how Covid-19 began in Wuhan?" said Alina Chan, a researcher with Harvard's Broad Institute, writing on Twitter. "That's the question you can answer for yourselves."</p>.<p>Serum samples still needed to be tested to make a stronger case about Covid-19's origins, said Stuart Turville, associate professor at the Kirby Institute, an Australian medical research organisation who was responding to the University of Kent study.</p>.<p>"Unfortunately with the current pressure of the lab leak hypothesis and the sensitivities in doing this follow-up research in China, it may be some time till we see reports like that," he said.</p>