On 16 November 2002, an outbreak of severe acute respiratory syndrome (SARS) began in China's Guangdong province, bordering Hong Kong. The first case of infection was traced to Foshan. This first outbreak affected people in the food industry, such as farmers, market vendors, and chefs. The outbreak spread to healthcare workers after people sought medical treatment for the disease
The first super-spreader, Zhou Zuofen, a fishmonger, checked in to the Sun Yat-sen Memorial Hospital in Guangzhou on 31 January, where he infected 30 nurses and doctors. The virus soon spread to nearby hospitals.
In February 2003, Hong Kong's SARS index patient was Liu Jianlun, who had come to attend a family wedding gathering; Liu was on the staff at Sun Yat-Sen Memorial Hospital in Guangdong and had treated SARS patients.
On 21 February, Liu and his wife checked into room 911 on the ninth floor of the Metropole Hotel. Despite feeling ill he visited with his family and they traveled around Hong Kong. By the morning of 22 February, he knew he was very sick and walked to nearby Kwong Wah Hospital to seek treatment. He warned staff that he was very sick and to put him in isolation. He never recovered and died in the intensive care unit on 4 March.
Liu is believed to have been a SARS super-spreader: 23 other Metropole guests developed SARS, including seven from the ninth floor. Liu's brother-in-law, who sought treatment in late February, was hospitalized in Kwong Wah Hospital on 1 March and died on 19 March. It is estimated that around 80% of the Hong Kong cases were due to Liu.[2