One of the earliest Wuhan MHC notices about the pneumonia epidemic. It was first posted on Weibo on 30 December 2019 and was confirmed by Wuhan CDC the next day (31 December).
The first confirmed patient started experiencing symptoms on 1 December 2019,[96] though the South China Morning Post later reported that the first case may have been a 55-year-old patient from Hubei province as early as 17 November.[97][98][99] More recently, on 27 March 2020, news outlets citing a government document reported that a 57-year-old woman, who started having symptoms on 10 December 2019 and subsequently tested positive for the coronavirus disease, was described in The Wall Street Journal on 6 March 2020, may have been patient zero in the coronavirus pandemic.[100][101]
Although the first confirmed patient did not have any exposure to Huanan Seafood Market, an outbreak of the virus began among the people who had been exposed to the market nine days later.[102][103] On 26 December, Shanghai PHC received a sample of a patient with unknown pneumonia from Wuhan CDC and Wuhan Central Hospital and started an investigation to the sample which was later confirmed to contain a new coronavirus.[102]
The outbreak went unnoticed until a cluster of unknown pneumonia cases was observed by Zhang Jixian,[104] director of the Department of Respiratory Medicine at Hubei Hospital of Integrated Traditional Chinese and Western Medicine,[105] whose experience fighting SARS in 2003 kept her alerted about a public health emergency. On 26 December 2019, a couple of seniors who lived near Zhang's hospital came to her for their fever and cough. The CT scan results of the couple's thorax showed unusual changes in the lungs which were different from those in any known viral pneumonia. Zhang saw the couple's son and found similar conditions. On the same day, a patient from Huanan Seafood Market that Dr. Zhang saw also had the unusual conditions.[106]
On 27 December, the doctor reported her discovery to her hospital and the hospital soon informed Jianghan CDC, thinking that this might be an infectious disease as it was indicated by the familial cluster. As a precaution, she told her colleagues to wear protective gear and prepare a specialized area in the hospital to receive patients with similar conditions.[106]
On 28 and 29 December, three more patients who had visited the Huanan Seafood Market visited the clinic of the hospital. The hospital notified the provincial and municipal health commissions. The health commissions appointed Wuhan and Jianghan CDC and Jinyintan Hospital to undertake epidemiological research for the seven patients on 29 December. Six of them were transferred to Jinyintan, a specialized facility for infectious diseases. Only one patient refused the transfer.[104][106] Zhang's discovery was widely praised;[107] the Hubei government honored her and Zhang Dingyu, the president of Jinyintan, for their contribution to controlling the viral outbreak.[105]