After receiving the report from Wuhan on 1 January 2020, WHO set up the Incident Management Support Team to deal with the potential outbreak. Three days later, WHO reported on its social media that a cluster of unknown pneumonia patients (with as yet no deaths) had been found in Wuhan, Hubei, China.8
The primary clinical symptoms of this unknown pneumonia at the time were fever and dyspnea (shortness of breath), and infiltrative lesions in both lungs (identifiable by X-ray or CT Scan). The Wuhan Municipal Government organised a group of experts in clinical medicine, epidemiology and virology to jointly study the unknown pneumonia.9 On 5 January 2020, the genetic sequence of the novel coronavirus was deposited in the GenBank, National Center for Biotechnology Information, U.S. National Library for Medicine, Bethesda, Maryland, U.S.A.10 On 7 January, laboratory analysis indicated that the viral pneumonia was caused by a novel coronavirus.11 Four days later, on 11 January, China publicly shared the gene sequence of this novel coronavirus (i.e. COVID-19) on the website of virological.org.12
On 13 January, Thailand confirmed its first case, and also the very first reported case outside of China. On 14 January, after the gene sequence of this novel coronavirus was disclosed by China, WHO named it 2019-nCoV.13
In the meantime, patients infected by the novel coronavirus had also been found on the Mainland outside of Hubei. On 19 January, Guangdong confirmed its first case in Shenzhen.14 On 20 January, Shanghai confirmed its first case and Beijing confirmed its first five cases.15,16 Within five days, COVID-19 patients were identified and reported in every province, municipality and autonomous region of China, with the exception of Tibet.17,18 Tibet reported its first case (and its only case as of this writing) on 28 January.19
With the rising number of newly confirmed cases and finding a history of contacts among patients, Professor ZHONG Nanshan, a well-respected Chinese medical and virological expert, determined that the unknown virus may be infectious during his inspection visit to Wuhan on 20 January.20 Two days later, WHO stated that there was evidence of human-to-human transmission in Wuhan, even though more investigation would be needed to fully understand the transmission.21 The human-to-human transmission and infectiousness was finally confirmed by an academic study published in The New England Journal of Medicine on 29 January 2020 (Li, et al., 2020).22
By 30 January, there were 82 confirmed cases spread over 18 countries outside of China. On that day, the WHO declared that the 2019-nCoV was a Public Health Emergency of International Concern. Later, on 11 February, WHO formally changed the name of the novel coronavirus from 2019-nCoV to COVID-19.23
On 12 February, Hubei changed its definition of a “confirmed” case to conform to the practice in the rest of the Mainland, that is, in the absence of results from a nucleic acid test, a combination of clinical symptoms is also sufficient to confirm a COVID-19 case. This change in definition led to a huge increase of newly confirmed cases from 1,638 on 11 February to 14,840 cases on 12 February in Hubei.24
Before 12 February, Hubei had maintained a stricter set of criteria for a confirmed coronavirus case than the rest of the Mainland. Among the three or four criteria for the determination of a confirmed case in Hubei, it was necessary for a patient to be tested positive by a specific nucleic acid test for the coronavirus virus. Even if a patient satisfied all of the other criteria, and despite observed clinical symptoms, he or she would not be classified as a confirmed case in the absence of this positive test. Under the new definition adopted by Hubei on 12 February, which has been and continues to be used in the rest of the Mainland, this condition is no longer absolutely necessary, as long as the other criteria are satisfied. This change in the definition led to the reclassification of many previously unconfirmed cases as confirmed cases, resulting in a steep one-time jump in the number of newly confirmed cases in Wuhan and Hubei on 12 February. However, the underlying situation remained the same; so we adjusted for this surge in the number of newly confirmed cases by smoothing it and then using the adjusted numbers for further analyses (see details in Appendix 1).
The time line of the events under “The Beginning” is presented in Table 2-1.
Table 2-1: The Beginning
| Date | Events |
| 1 December 2019 | The first COVID-19 case was confirmed in Wuhan. |
| 31 December 2019 | The Wuhan Municipal Health Commission reported identifying 27 cases of unknown viral pneumonia, but no evidence of human-to-human transmission had been confirmed. |
| 31 December 2019 | An inspection team led by the Director of the China Center for Disease Control and Prevention arrived in Wuhan to carry out an examination of the unknown viral pneumonia. |
| 1 January 2020 | The National Health Commission of China set up a Leading Group for Epidemic Prevention and Control. |
| 1 January 2020 | The South China Seafood Market, the suspected origin of the COVID-19 virus, was closed by the Wuhan Municipal Government. |
| 4 January 2020 | The World Health Organization (WHO) reported a cluster f unknown pneumonia cases in Wuhan on its social media. |
| 5 January 2020 | The genetic sequence of the novel coronavirus was deposited in the GenBank, National Center for Biotechnology Information, U.S. National Library for Medicine, Bethesda, Maryland, U.S.A. |
| 7 January 2020 | Laboratory analysis indicated that the pathogen of the unexplained viral pneumonia in Wuhan was caused by a novel coronavirus. |
| 10 January 2020 | China publicly shared the genetic sequence of the novel coronavirus on the website of virological.org. |
| 13 January 2020 | The first confirmed case outside of China was found in Thailand. |
| 14 January 2020 | WHO officially named the novel coronavirus 2019-nCoV. |
| 19 January 2020 | The first confirmed case on the Mainland outside of Hubei was reported in Shenzhen, Guangdong Province. |
| 20 January 2020 | The first confirmed case was reported in Shanghai and the first five confirmed cases were reported in Beijing. |
| 20 January 2020 | Prof. ZHONG Nanshan, a medical and virological expert, visited Wuhan for an inspection and determined that the 2019-nCoV pneumonia could be transmitted from human to human. |
| 22 January 2020 | Confirmed cases were reported in the Provinces of Fujian, Guangxi, Guizhou, Hainan, Henan, Jiangsu, Jilin, Liaoning, Ningxia, Shaanxi and Shanxi. Cases were reported in Gansu, Xinjiang and Qinghai in the following two days. |
| 24 January 2020 | A study on the clinical features of the COVID-19 virus found in Wuhan was published in The Lancet. |
| 25 January 2020 | Confirmed cases were reported in Shandong, Tianjin and Yunnan, thus covering the entire country except Tibet. |
| 28 January 2020 | The first and only case was reported in Tibet. |
| 29 January 2020 | The possibility of human-to-human transmission of the virus was formally confirmed in a scientific study published in The New England Journal of Medicine. |
| 30 January 2020 | WHO declared the novel coronavirus outbreak (2019-nCoV) a “Public Health Emergency of International Concern”. |
The Blockade and Lockdown
On 14 January, WHO noted at a media briefing that there might be limited human-to-human transmission of the viral pneumonia caused by a novel coronavirus. On that day, the cumulative total number of confirmed cases and deaths in Wuhan were 41 and 1, respectively. However, in the following week, the cumulative total number of confirmed cases and deaths in Wuhan increased rapidly to 425 and 17, respectively. Moreover, beginning on 19 January, the COVID-19 virus gradually spread to many other provinces and cities outside of Hubei and Wuhan.
In order to prevent the further spread of the disease, Hubei was gradually sealed