Hong Kong is well equipped to face an epidemic after the experience of Sars 10 years ago, when health workers "fought in the dark" for weeks, experts in infectious diseases say.
The outbreak of severe acute respiratory syndrome led to new health practices and new techniques in combating diseases.
But Dr Margaret Chan Fung Fu-chun, who led the city's battle and is now chief of the World Health Organisation, sees it as a 21st century disease defeated using 19th century tools.
"Sars taught the importance of meeting an emergency with whatever tools are at hand," Chan writes in an article for the South China Morning Post on her thoughts from those unforgettable days, telling of the helplessness in facing the mysterious enemy.
Approaching the 10th anniversary of the Sars outbreak, health professionals and policymakers are looking back at their experience in fighting the worldwide health threat, the lessons learned, and sharing its implications for the present and future.
It was around this time of the year, in 2003, that the coronavirus which caused Sars - the identity of which was a mystery at the time - was carried into Hong Kong, where it went on to infect 1,755 people, killing 299 of them. Worldwide, 8,096 were infected, of whom 744 died.
The rate of infection was alarming - a physician's one-night stay in the Metropole Hotel, Mong Kok, resulted in 16 other hotel guests being infected. One of them went to Prince of Wales Hospital for treatment, leading to 138 infections in the hospital within two weeks, including many health-care workers.
"To me, it was a shock in the beginning that we were dealing with such a dangerous infection and were totally unprepared," said Chinese University vice chancellor Joseph Sung Jao-yiu, dubbed one of the "Sars heroes" for his frontline work in treating the first batch of patients.
Professor David Hui Shu-cheong, director of the emerging infectious disease centre at the university, said: "In those first few weeks we were fighting in the dark, not knowing who and where the enemy was."
Today, the situation would be far different in the event of another Sars-like epidemic, the experts say. Hospital wards have implemented strict measures to control infectious diseases, doctors can uncover the travel history of patients and they have more established practices for the wearing of protective gear.
But problems like crowded wards in public hospitals still need resolving, given the small distance between beds increases the risk of infections, said Professor Nelson Lee Lai-shun, head of the infectious diseases division at Chinese University.
The emergence of the powerful virus led to various clinical studies on new treatment methods, but Lee said: "It's been 10 years and the passion has died down. Now there are fewer people doing studies on infectious diseases. I hope there will be more in the future."
Margaret Chan sees Sars as a disease of wealthy urban centres, showing that developed countries could also be threatened by new diseases.
Sung, speaking of his biggest lesson learned from Sars, agreed.
"Infectious diseases do not belong only to developing countries but to cosmopolitan cities like Hong Kong. We are actually more exposed to various types of infections because of international travel. Therefore education, training and research are of the utmost importance."