Late December 2019

-- The Wuhan Center for Disease Control and Prevention (CDC) in central China's Hubei Province detected cases of pneumonia of unknown cause.

Dec 30, 2019

-- The Wuhan Municipal Health Commission issued an urgent notification to medical institutions under its jurisdiction, ordering efforts to appropriately treat patients with pneumonia of unknown cause.

Dec 31, 2019

-- The National Health Commission (NHC) made arrangements in the wee hours, sending a working group and an expert team to Wuhan to guide epidemic response and conduct on-site investigations.

-- The Wuhan Municipal Health Commission released a briefing on its website about the pneumonia outbreak in the city, confirming 27 cases and telling the public not to go to enclosed public places or gather. It suggested wearing face masks when going out.

-- Starting Dec 31, 2019, the Wuhan Municipal Health Commission released briefings on the pneumonia outbreak in accordance with the law.

January 2020

Jan 1

-- The NHC set up a leading group to determine the emergency response to the epidemic. The group convened meetings on a daily basis since then.

Jan 2

-- The Chinese Center for Disease Control and Prevention (China CDC) and the Chinese Academy of Medical Sciences (CAMS) received the first batch of samples of four patients from Hubei Province and began pathogen identification.

-- The NHC came up with a set of guidelines on early discovery, early diagnosis and early quarantine for the prevention and control of the viral pneumonia of unknown cause.

Jan 3

-- Starting Jan 3, China has been regularly informing the WHO, relevant countries and regions and China's Hong Kong, Macao and Taiwan about the pneumonia outbreak.

-- China began to inform the United States of the pneumonia outbreak and response measures on a regular basis.

-- The Wuhan Municipal Health Commission updated briefing on its website about the situation of viral pneumonia of unknown cause, reporting a total of 44 cases of viral pneumonia of unknown cause.

-- The NHC organized the China CDC and three other institutions to carry out parallel laboratory testing of the samples for pathogen identification.

-- The NHC and the Health Commission of Hubei Province jointly worked out nine documents on the outbreak, including a trial version of guidelines on the diagnosis and treatment of viral pneumonia of unknown cause.

Jan 4

-- The NHC and relevant health departments in Hubei Province issued a treatment manual for viral pneumonia of unknown cause to all medical institutions in Wuhan City, and provided citywide training.

-- Head of the China CDC talked over phone with director of the US CDC about the pneumonia outbreak. The two sides agreed to keep in close contact for information sharing and technological cooperation.

Jan 5

-- The Wuhan Municipal Health Commission updated briefing on the situation of viral pneumonia of unknown cause, reporting a total of 59 cases. Laboratory test results ruled out respiratory pathogens, such as influenza, avian influenza, adenovirus, the Severe Acute Respiratory Syndrome coronavirus, and Middle East Respiratory Syndrome coronavirus, as the cause.

-- China informed the WHO about the outbreak updates.

-- The WHO released its first briefing on cases of pneumonia of unknown cause in Wuhan.

Jan 6

-- The NHC gave a briefing on cases of pneumonia of unknown cause at a national health conference, calling for efforts to strengthen monitoring, analysis and study, and make timely response.

Jan 7

-- Xi Jinping, general secretary of the CPC Central Committee, made instructions on epidemic response when presiding over a meeting of the Standing Committee of the Political Bureau of the CPC Central Committee.

-- The China CDC succeeded in isolating the first novel coronavirus strain.

Jan 8

-- An expert evaluation team from the NHC initially identified a new coronavirus as the cause of the epidemic.

-- Heads of China and US CDCs talked over phone to discuss technological exchanges and cooperation.

Jan 9

-- An expert team from the NHC made public of the pathogen, saying a new type of coronavirus was initially identified as the cause of the viral pneumonia in Wuhan.

-- China informed the WHO about the epidemic, sharing with the WHO the initial progress in determining the cause of the viral pneumonia in Wuhan.

-- The WHO released on its website a statement regarding a cluster of pneumonia cases in Wuhan, saying that preliminary identification of a novel coronavirus in a short period of time is a notable achievement.

Jan 10

-- Research institutions including the Wuhan Institute of Virology (WIV) developed testing kits. Wuhan City organized tests of all relevant cases admitted at hospitals in the city.

-- Head of the NHC Ma Xiaowei talked over phone with WHO Director-General Tedros Adhanom Ghebreyesus about the epidemic response.

-- Head of China CDC exchanged information over phone with WHO Director-General Tedros Adhanom Ghebreyesus.

-- The China CDC shared with the WHO the specific primers and probes for detecting the novel coronavirus.