A scientist who has pored over public accounts of early Covid-19 cases in China says that an influential World Health Organization inquiry had likely got the early chronology of the pandemic wrong. The new analysis suggests that the first known patient sickened with the coronavirus was a vendor in a large Wuhan animal market, not an accountant who lived many kilometres away from it.
The report, published on Thursday in the prestigious journal Science, will revive, although certainly not settle, the debate over whether the pandemic started with a spill over from wildlife sold at the market, a leak from a Wuhan virology laboratory, or some other way. The search for the origins of the greatest public health catastrophe in a century has fuelled geopolitical battles, with few new facts emerging in recent months to resolve the question. The scientist, Michael Worobey, an expert in tracing the evolution of viruses at the University of Arizona, came upon timeline discrepancies by combing through what had already been made public in medical journals, as well as video interviews in a Chinese news outlet with people believed to have the first two documented infections. Worobey argues that the vendor’s ties to the Huanan Seafood Wholesale Market, as well as a new analysis of the earliest hospitalised patients’ connections to the market, strongly suggest that the pandemic began there. “In this city of 11 million people, half of the early cases are linked to a place that’s the size of a soccer field,” Worobey said. “It becomes very difficult to explain that pattern if the outbreak didn’t start at the market.” Several experts, including one of the pandemic investigators chosen by the WHO, said Worobey’s detective work was sound and that the first known case of Covid was most likely a seafood vendor. But some of them also said the evidence was still insufficient to decisively settle the larger question of how the pandemic began. They suggested that the virus probably infected a “patient zero” sometime before the vendor’s case and then reached critical mass to spread widely at the market. Studies of changes in the virus’s genome — including one done by Worobey himself — have suggested that the first infection happened in roughly mid-November 2019, weeks before the vendor got sick. “I don’t disagree with the analysis,” said Jesse Bloom, a virus expert at the Fred Hutchinson Cancer Research Center in Seattle. “But I don’t agree that any of the data are strong enough or complete enough to say anything very confidently, other than that the Huanan Seafood Market was clearly a superspreading event.” Bloom also noted that this was not the first time the WHO report, done in collaboration with Chinese researchers, was found to contain mistakes, including errors involving early patients’ potential links to the market. “It’s just kind of mind-boggling that in all of these cases, there keep being inconsistencies about when this happened,” he said. ’The Mistake Lies There’ Toward the end of December 2019, doctors at several Wuhan hospitals noticed mysterious cases of pneumonia arising in people who worked at the Huanan Seafood Wholesale Market, a dank and poorly ventilated space where seafood, poultry, meat and wild animals were sold. On Dec 30, public health officials told hospitals to report any new cases linked to the market. Fearing a replay of severe acute respiratory syndrome, which emerged from Chinese animal markets in 2002, Chinese officials ordered the Huanan market closed, and Wuhan police officers shut it down on Jan 1, 2020. Despite those measures, new cases multiplied through Wuhan. Wuhan authorities said on Jan 11, 2020, that cases had begun on Dec 8. In February, they identified the earliest patient as a Wuhan resident with the surname Chen, who fell sick on Dec 8 and had no link to the market. Chinese officials and some outside experts suspected that the initially high percentage of cases linked to the market might have been a statistical fluke known as ascertainment bias. They reasoned that the Dec 30 call from officials to report market-linked illnesses may have led doctors to overlook other cases with no such ties. “At the beginning, we presumed that the seafood market may have the novel coronavirus,” Gao Fu, director of China’s Centers for Disease Control and Prevention, said in May 2020, according to China Global Television Network. “But it now turns out that the market is one of the victims.” By the spring of 2020, senior members of the Trump administration were promoting another scenario for the origin of the pandemic: that the virus had escaped from the Wuhan Institute of Virology, which has a campus roughly 8 miles away from the Huanan market, across the Yangtze River. In January of this year, researchers chosen by the WHO visited China and interviewed an accountant who had reportedly developed symptoms on Dec 8. Their influential March 2021 report described him as the first known case. But Peter Daszak, a disease ecologist at EcoHealth Alliance who was part of the WHO team, said that he was convinced by Worobey’s analysis that they had been wrong. “That December the 8th date was a mistake,” Daszak said. The WHO team never asked the accountant the date his symptoms began, he said. Instead, they were given the Dec 8 date by doctors from Hubei Xinhua Hospital, who handled other early cases but did not care for Chen. “So the mistake lies there,” Daszak said. For the WHO experts, Daszak said, the interview was a dead end: The accountant had no apparent links to an animal market, lab or a mass gathering. He told them he liked spending time on the internet and jogging, and he did not travel much. “He was as vanilla as you could get,” Daszak said. Had the team identified the seafood vendor as the first known case, Daszak said, it would have more aggressively pursued questions like what stall she worked in and where her products came from. While the doctors at Hubei Xinhua Hospital said the onset of the accountant’s illness had been Dec 8, a senior doctor at Wuhan Central Hospital, where Chen was treated, had told a Chinese news outlet that he developed symptoms around Dec 16. Asked about Chen’s case, China’s National Health Commission said it stood by comments made by Liang Wannian, the leader of the Chinese side of the WHO-China investigation who led the interview with the Hubei Xinhua Hospital doctors. Liang told a news conference in February of this year that the earliest Covid case showed symptoms on Dec 8 and was “not connected” to the Huanan market.
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