For a few months in 2003, SARS held Hong Kong in virtual quarantine. Schools closed. Employees worked from home. Hardly anyone traveled. When they did go out, many people wore surgical masks.
A similar scene is now playing out in Mexico, as swine flu grips that nation. With about 150 deaths blamed on the virus, the government has closed schools, museums and public buildings. Mexico City's normally bustling streets are empty.
Elaine Leung, a Chinese language teacher in Hong Kong, was finishing her undergraduate degree at Lingnan University here when SARS struck. She recalls weeks of being confined to her dormitory.
"We were not stuck, we were free to move. But the point is there was no way that we can move. At that moment if we moved back home, then if we carried any virus that might affect our family we better stay where we're from, so that's our idea," she said.
There have been no reported cases of swine flu in Hong Kong.
Even if swine flu turns up in Hong Kong, Under-Secretary for Food and Health Gabriel Leung says the city is better equipped than others may be, having learned from SARS.
"That gave us a lot of valuable insights and practical experience in managing a large-scale outbreak that eventually spread to other parts of the world. And I think that certainly has prepared us very well for what may come as far as [a] human swine flu epidemic is concerned," he said.
SARS swept into Hong Kong for four months in 2003, infecting 1,755 people and killing 299 by June. Worldwide, more than 8,000 were infected and nearly 800 died from SARS.
Hong Kong has stockpiled 20 million doses of antiviral drugs such as Tamiflu. It has set aside 1,400 hospital beds in isolation wards. And it regularly scans body temperatures of incoming travelers and quarantines any who are suspect.
Stringent infection-control measures were put in place during the SARS outbreak, which started when a visiting doctor who had been treating victims in southern China became ill.
Because the disease was so new, it took health authorities a few days to grasp the seriousness of the situation. They sought information from health officials in China, but were rebuffed. Before they could identify the new disease, travelers had spread it to several countries in Asia and to North America.
With the number of people suffering fevers and pneumonia-like symptoms increasing, authorities closed schools and quarantined buildings were clusters of infections were found.
Business declined as tourist numbers dropped and city residents gave up dining in restaurants and shopping in malls. The stock market fell sharply.
This week, the World Health Organization warned swine flu may have pandemic potential. The WHO is urging nations to take precautions to limit the virus' spread.
Confirmed cases have been reported in Europe, Israel, the United States and Canada. In the Asia-Pacific region, there are suspected cases in a handful of countries, and New Zealand has confirmed several swine flu infections.
Hong Kong's Center for Health Protection Controller Thomas Tsang says flu is very unpredictable.
"It really can happen anywhere in the world. That is why it is important to maintain vigilance. Not just at a particular geographical segment, but we should have a worldwide vision to monitor closely the influence of influenza, whether it is swine influenza or avian influenza or human influenza," he said.
Hong Kong plans to quarantine anyone with a fever who arrives from an area infected with swine flu. In addition, the city is ready to close schools and impose widespread quarantines if swine flu begins to spread to the city. Tsang also says the government and the medical universities are working to create a test that could confirm swine flu within hours instead the two or three days it takes now.
There is little alarm in the streets. Although there are some reports of Hong Kong residents lining up to buy surgical masks and hand disinfectant, drug stores have not been swamped, as they were during SARS.