A leading Chinese virology expert has warned that the Wuhan coronavirus epidemic could be 10 times as bad as the Sars outbreak that killed almost 800 people around the world in 2002-03. Guan Yi, director of the State Key Laboratory of Emerging Infectious Diseases at Hong Kong University, said in an interview with Caixin magazine on Thursday that after a brief visit to the central China city on Tuesday and Wednesday, he “chose to become a deserter” and left. “My conservative estimate is that this epidemic could end up at least 10 times the scale of Sars [severe acute respiratory disease],” he said. During the Sars outbreak, which was also caused by a coronavirus, 8,437 people fell ill around the world and 813 died, according to figures from the World Health Organisation (WHO). In mainland China there were 5,327 cases and 348 deaths, and in Hong Kong, 1,755 cases and 298 deaths. As of midnight Thursday, there had been 17 deaths and 583 confirmed cases of the new coronavirus – named 2019-nCoV by the WHO. Hubei province, of which Wuhan is the capital, has accounted for all of the fatalities and 444 cases of the 571 confirmed cases in mainland China. The 12 other cases were reported in Thailand, South Korea, Japan, the United States, and the cities of Hong Kong and Macau. Tracking coronavirus a ‘jigsaw puzzle’ as China goes into quarantine mode One of the reasons for the prediction was that authorities in Wuhan had missed their best opportunity to contain the spread of the disease, Guan said. Although a travel ban had been introduced in the city on Thursday morning, the “golden time” to contain the virus had passed, as most of the people travelling home for the Lunar New Year holiday had already left, he said. “They might have been in contact with patients in the community and still in the incubation stage when they left Wuhan. They are probably virus carriers on the move.” On Wednesday alone, 299,600 train passengers departed from Wuhan, one of China’s busiest transport hubs, according to figures from the local railway authority. Information on the number of people who had left the city by air, road or river was not immediately available. Guan said he expected the outbreak to peak over the weekend, as the virus had an incubation period of about eight days. He said also that vital evidence that could have been used to trace the source of the virus had been destroyed when the seafood market in Wuhan – the epicentre of the outbreak – was washed clean. Meanwhile, Chinese health authorities said on Thursday that the outbreak in Wuhan had become a full-blown community epidemic. The Centre for Disease Control and Prevention (CDC) said in its latest report that more than half of the 198 infected people it had surveyed had never been to the seafood market in Wuhan, nor had they had any contact with infected patients. “Transmission within communities is believed to be taking place in Wuhan,” the report said. Its assessment “indicated that the epidemic is ongoing in Wuhan and that further spread is almost certain”. Community outbreak is the stage in the spread of a disease when it expands from transmission within families and hospitals, to the wider community. The epidemiological investigation found that 51 per cent of patients studied had neither visited Huanan Seafood Wholesale Market nor had contact with infected patients, the CDC said. Only 22 per cent had had direct exposure to the market, and 32 per cent had had contact with other people showing fever or respiratory symptoms, it said. The CDC said that another health care worker was suspected to be infected, in addition to the 15 already confirmed in Wuhan. In a press conference on Wednesday, Li Bin, director of the National Health Commission, said community outbreaks had been found in only “certain areas of the city”. Purchase the China AI Report 2020 brought to you by SCMP Research and enjoy a 20% discount (original price US$400). This 60-page all new intelligence report gives you first-hand insights and analysis into the latest industry developments and intelligence about China AI. Get exclusive access to our webinars for continuous learning, and interact with China AI executives in live Q&A. Offer valid until 31 March 2020.