DEC 31, 2019
The World Health Organisation (WHO) is alerted by the Chinese authorities about a string of pneumonia-like cases in Wuhan, a city of 11 million people.
Patients are quarantined and work begins on identifying the origin of the pneumonia.
The United States Centres for Disease Control and Prevention (CDC) identifies a seafood market suspected to be at the centre of the outbreak. It is closed on Jan 1, 2020.
JAN 9, 2020
The WHO says that the outbreak in Wuhan was caused by a previously unknown type of coronavirus, which covers a broad family ranging from the common cold to more serious illnesses like Sars.
Fifty-nine people are reported to have been infected, with seven in a serious condition.
The Chinese health authorities report the death of the first person from the virus.
It is known for the first time that the virus has spread beyond China's borders with a case emerging in Thailand, according to the WHO. The victim is a Chinese woman diagnosed with mild pneumonia who was returning from a trip to Wuhan.
On Jan 15, China's health commission says no human-tohuman transmission of the virus behind the Wuhan outbreak has been confirmed so far, but the possibility "cannot be excluded".
The next day, Japan confirms its first case of the virus in someone who had stayed in Wuhan in early January.
A second person, a 69-year-old man, dies in Wuhan, according to the authorities.
The same day, the CDC announces that it will begin screening passengers arriving from Wuhan at three US airports: San Francisco, New York's JFK and Los Angeles.
Human to human
On Jan 20, a third death and more than 100 new cases are announced in China, sparking concerns ahead of the annual Chinese New Year holiday which begins on Jan 25 and sees hundreds of millions of Chinese people travel nationwide.
The virus is present in Beijing in the north, Shanghai in the east and Shenzhen in the south. More than 200 cases have been recorded. The virus is also detected in South Korea in a Chinese person who had arrived by plane from Wuhan.
China's President Xi Jinping says the virus must be "resolutely contained", in his first public comments on the outbreak.
Human-to-human transmission is "affirmative", top Chinese infectious diseases expert Zhong Nanshan tells state broadcaster CCTV.
Wuhan officials reveal three more deaths in the city, bringing the tally to six as the number of confirmed cases in mainland China inches closer to 300.
By this time, the virus is known to have affected people in Hubei - where Wuhan is located - Beijing, Guangdong, Shanghai and Zhejiang in China.
Elsewhere, Taiwan reports its first confirmed case of infection - a Taiwanese businesswoman in her 50s who flew back home from Wuhan on Jan 20.
AGENCE FRANCE-PRESSE, REUTERS