This article documents the chronology and epidemiology of SARS-CoV-2 in January 2020, the virus which causes the coronavirus disease 2019 (COVID-19) and is responsible for the COVID-19 pandemic. The first human cases of COVID-19 were identified in Wuhan, China, in December 2019.
Pandemic chronology Background
Phylogenetic analyses estimate that SARS-CoV-2 first arose in October or November 2019, evolving from a coronavirus that infects wild bats and spreading to humans through an intermediary wildlife host. While later research determined that a first patient began to show symptoms as early as 1 December 2019, a cluster of cases was not discovered until the end of December. Retrospective study would later indicate that 266 people had been infected before the beginning of 2020. On 31 December, the Wuhan Municipal Health Commission released a briefing on its website about early signs of a pneumonia outbreak in the city. International news agencies began to report on the outbreak that day, as did the WHO and the US CDC.
1 January
Xinhua News reported that the Huanan Seafood Market was closed on 1 January 2020 for cleaning and disinfection.
US CDC Director Robert Redfield was briefed about the severity of the virus from his Chinese counterpart George F. Gao when he was on vacation with his family—according to reports, what he heard "rattled him".
The WHO Newsroom stated that "the causal agent has not yet been identified or confirmed", and noted it had requested further information from the Chinese authorities to assess the risk.
2 January A later, February study of patients admitted to the hospital in Wuhan between 16 December 2019 and 2 January 2020 was able to identify, during this time period, a total of 41 patients had contracted the novel coronavirus, 27 (66%) with direct exposure to Huanan Seafood Wholesale Market. All 41 patients were subsequently relocated from the hospital they had originally been diagnosed in to the Jinyintan Hospital in Wuhan, China. WHO declared that its three concerned levels (China country office, Regional Office for the Western Pacific and headquarters) have been working together to respond to the outbreak.
3 January The Chinese government formally notified the US of the outbreak. At a White House briefing in 20 March, Health and Human Services Secretary Alex Azar said officials had been alerted to the initial reports of the virus by discussions between CDC director Robert Redfield and Chinese CDC Director Gao on 3 January. Mr. Azar also told his chief of staff to make sure that the National Security Council was aware that "this (the outbreak) is a very big deal".C-Span. (20 March 2020). White House Coronavirus News Conference. YouTube website approx. 1 hour 2 minutes in. Retrieved 20 March 2020. The BBC ran its first story on the outbreak.
Health authorities in Wuhan reported 44 cases, a big jump from the 27 reported on Tuesday. Eleven of the 44 were seriously ill, the Wuhan Municipal Health Commission said, although there had been no reported deaths to date. The health of the 121 close contacts of the cases was being monitored.
Chinese scientists at the National Institute of Viral Disease Control and Prevention (IVDC) ruled out the possibilities for 26 common respiratory pathogens, including influenza A and B virus, parainfluenza virus, adenovirus, respiratory syncytial virus metapneumovirus rhinovirus, enterovirus, and other common respiratory viruses. They determined the genetic sequence of the novel β-genus coronaviruses (naming it '2019-nCoV') from specimens collected from patients in Wuhan, China, and three distinct strains were established.
China's National Health Commission (NHC) ordered institutions to not publish any information that related to the disease, and ordered labs to either transfer all samples to designated testing institutions, or destroy them. The order did not list any designated testing institutions.
Li Wenliang, a Wuhan ophthalmologist, was summoned to the Wuhan Public Security Bureau where he was told to sign an official confession and admonition letter promising to cease spreading "false" "rumors" regarding the coronavirus. In the letter, he was reprimanded for "making false comments by announcing the confirmation of 7 cases of SARS at the Huanan Seafood Wholesale Market" that had "severely disturbed the social order". The letter stated, "We solemnly warn you: If you keep being stubborn, with such impertinence, and continue this illegal activity, you will be brought to justice—is that understood?" Li signed the confession writing: "Yes, I understand."
4 January The United Nations agency activated its incident-management system at the country, regional, and global level and was standing ready to launch a broader response if it was needed. The WHO's regional office in Manila said in Twitter posts Saturday: "#China has reported to WHO regarding a cluster of pneumonia cases in Wuhan, Hubei Province. The Govt has also met with our country office, and updated @WHO on the situation. Govt actions to control the incident have been instituted and investigations into the cause are ongoing." The US CDC Director Redfield, following up the previous day's contact, emailed the Chinese CDC Director, Gao, formally offering to send US experts to China to investigate the outbreak.
The head of the University of Hong Kong's Center for Infection, Ho Pak-Leung, warned that the city should implement the strictest possible monitoring system for a mystery new viral pneumonia that infected dozens of people on the mainland, as it was highly possible that the illness was spreading from human to human. The microbiologist also warned that there could be a surge in cases during the upcoming Chinese New Year. Ho said he hoped the mainland would release more details as soon as possible about the patients infected with the disease, such as their medical history, to help experts analyze the illness and to allow for more effective preventive measures to be put in place.
The Singapore Ministry of Health said on Saturday, 4 January, that it had been notified of the first suspected case of the "mystery Wuhan virus" in Singapore, involving a three-year-old girl from China who had pneumonia and a travel history to the Chinese city of Wuhan. On 5 January, the Singapore Ministry of Health released a press statement stating that the earlier suspected case was not linked to the pneumonia cluster in Wuhan and was also tested negative for the SARS and MERS-CoV.
On 4 January, journalist Helen Branswell wrote that, while social media platforms suggested that China was not being transparent about the outbreak, scientists disagreed. Virologist Ralph Baric commented, "They have many of the best virologists in the world there that are working on this."
5 January The number of suspected cases reached 59 with seven in a critical condition. All were quarantined and local medical officials commenced the monitoring of 163 of their contacts. At this time, there had been no reported cases of human-to-human transmission or presentations in healthcare workers.
Zhang Yong-Zhen, a virologist at Fudan University, deposits the second known complete genome (Wuhan-Hu-1) in sequence database GenBank. The sequence record was initially embargoed and thus not visible to the public.
Early investigations into the cause of the pneumonia ruled out seasonal flu, SARS, MERS, and bird flu.
Disease Outbreak News was WHO's first international media report summarizing details of the Wuhan outbreak.
6 January On Monday, 6 January, the Wuhan health authorities announced they continued seeking the cause but had so far ruled out influenza, avian influenza, adenovirus, and coronaviruses SARS and MERS as the respiratory pathogen that had infected 59 people as of 5 January. The New York Times ran its first story on the outbreak.
7 January Scientists of the National Institute of Viral Disease Control and Prevention (IVDC) confirmed the novel coronavirus isolated on 3 January was the pathogenic cause of the viral pneumonia of unknown etiology (VPUE) cluster, and designated the disease as a novel coronavirus-infected pneumonia (NCIP). Scientists in China announced the discovery of a new coronavirus.
In a closed meeting of the Politburo of the Chinese Communist Party, Xi Jinping "made requests for the prevention and control work of the coronavirus outbreak" and issued instructions to similar ends. This meeting occurred 13 days before Xi's first public comments on the outbreak on 20 January.
Since the outburst of social media discussion of the mysterious pneumonia outbreak in Wuhan, China, Chinese authorities censored the hashtag #WuhanSARS and were now investigating anyone who was allegedly spreading misleading information about the outbreak on social media.
The US Centers for Disease Control and Prevention (CDC) created an "incident management system" and issued a travel notice Monday for travellers to Wuhan, Hubei province, China due to the cluster of cases of pneumonia of an unknown etiology".
8 January South Korea authorities put a 36-year-old Chinese woman under isolated treatment amid concerns that she had brought back a form of viral pneumonia that had sickened dozens in mainland China and Hong Kong in the previous weeks. The unidentified woman, who worked for a South Korean company near capital Seoul, had experienced cough and fever since returning from a five-day trip to China on 30 December, the KCDC said in a press release. The woman had spent time in Wuhan, China, but had not visited the Huanan Seafood Market.
9 January First reported death The first death from the virus occurred in a 61-year-old man who was a regular customer at the market. He had several significant medical conditions, including chronic liver disease, and died from heart failure and pneumonia. The incident was reported in China by the health commission via Chinese state media on 11 January.
The WHO confirmed that the novel coronavirus had been isolated from one person who had been hospitalized. On the same day, the European Centre for Disease Prevention and Control posted its first risk assessment. The WHO also reported that Chinese authorities had acted swiftly, identifying the novel coronavirus within weeks of the onset of the outbreak, with the total number of positively tested people being 41.
Chinese scientists reported on Chinese state broadcaster CCTV that they had found a new "coronavirus in 15 of 57 patients with the illness in the central city of Wuhan, saying it has been preliminarily identified as the pathogen for the outbreak". The scientists announced that the current 'Wuhan Virus', a coronavirus, appears to not be as lethal as SARS. They reported that the new viral outbreak was first detected in the city of Wuhan on 12 December 2019. Additionally, a total of 59 people have been identified as contracting the illness, seven patients had been in a critical condition at some stage, and no healthcare workers were reported as having been infected.
10 January Genome sequence becomes public The genome of the isolated 2019-nCoV, a virus from the same family as the SARS coronavirus, was posted on Virological.org by Edward Holmes on behalf of Zhang Yong-Zhen of Fudan University, Shanghai. The sequence had already been uploaded to GenBank on 5 January 2020, but was embargoed and thus not available to the public. Shortly thereafter, three genetic sequences of the isolated novel coronavirus from the Chinese Center for Disease Control and Prevention, one from the Chinese Academy of Medical Sciences, and one from Wuhan Jinyintan Hospital were posted to GISAID.