This story is part of VOA's 2003 in Review series
Severe Acute Respiratory Syndrome appeared a year ago in China, and went on to infect more 8,000 people worldwide. For months, doctors fought the potentially deadly disease, while scientists tracked its origins and government leaders worldwide worried about the damage it could do to health-care systems and economies. The mysterious new disease that became known as Severe Acute Respiratory Syndrome caught international attention when a doctor from mainland China sparked an outbreak in Hong Kong in February.
Joseph Sung, a senior doctor at Hong Kong's Prince of Wales Hospital, recalls the city's first known case, a man who later died of the disease.
"He came to Hong Kong at the end of February to attend his relative's wedding banquet," he said. "He stayed in a hotel and on the same floor there are at least 10 people who got infected. … These 10 people … carried the infection to eight different countries."
By mid-March, hospitals in Hong Kong, Vietnam, Canada and Singapore were treating dozens of SARS patients, many of them medical workers, leaving hospitals short-handed.
There was near panic in some parts of Asia as the disease spread and hospitals grew crowded with patients. People wore face masks in an effort to avoid catching the mysterious illness. Governments rushed out new programs to clean up streets and encourage citizens to wash their hands. Schools were closed and restaurants in Hong Kong and Singapore stood empty as people avoided crowded places.
Typically, SARS victims suffer uncontrollable high fevers accompanied by breathing trouble. Most develop a serious pneumonia.
The disease spread quickly in part because Chinese officials had kept quiet when it appeared in southern China in November 2002. Dr. Sung in Hong Kong says the city was unprepared.
"Information was not given to everybody so we were not alert about a possible major disaster coming," said Dr. Sung.
For weeks, mainland officials played down the link between the disease spreading around the world, and similar cases in China. On March 22, then-Chinese Health Minister Zhang Wenkang visited Hong Kong.
Mr. Zhang said it was impossible to see if pneumonia cases in China were related to SARS.
China insisted there were few cases of the disease in the country. Then a doctor in Beijing revealed that hospitals were overflowing with patients suffering from an illness that fit the description for SARS.
The World Health Organization helped China set up a system to track SARS cases. Soon it became clear the virus had infected thousands more victims than previously reported. The health minister was fired.
"What I think China has learned so very clearly, in order to fight infectious disease you have to have the right political commitment," said Henk Bekedam, who led the WHO effort in China. "Also sharing of information needs to be done at an early stage and it needs to be done with international cooperation."
To fight the virus, the scientists around the world mobilized.
The WHO set up an online system for SARS research, tying together more than 13 laboratories worldwide. In a few months, the likely cause of SARS was found.
In March, Hong Kong scientists identified a coronavirus, from a group of viruses associated with the common cold, as the cause of SARS. In April, a number of labs decoded the genetic sequence of the virus.
In May, a team of microbiologists led by K.Y. Yeun at Hong Kong University announced SARS had likely jumped from animals to humans.
"We known that the source is in wild animals, so the wild game animals are not being controlled there is always a likelihood that it [can] jump into humans," he said.
In July, seven months after SARS emerged in southern China, the WHO announced the global outbreak had been contained. More than 8,000 people worldwide had been infected. Two-thirds of the cases, and most of the 700 SARS deaths, were in mainland China and Hong Kong.
The United Nations agency says the outbreak was contained in part because travelers were warned to avoid infected areas. In addition, most countries where SARS appeared quarantined people who came in contact with its victims.
But warnings to defer travel had high economic costs. Business plunged for airlines, hotels and restaurants in Singapore, China, Hong Kong and Toronto. Hong Kong's economy sank sharply. Singapore saw unemployment rise.
Philip Wickham is an airline analyst with ING Barings investment bank. He says that even non-Asian airlines saw sales fall.
"The Asian operation for all the global airlines just collapsed during this period," said Wickham. "For the Asian carriers, all of them had unprecedented declines."
Health officials around the world are now waiting for SARS to return, which many scientists think could happen soon as winter settles into the Northern Hemisphere.
SARS vaccines are being created, but they will not be ready for years.
The WHO stresses the best way to prevent new outbreaks is to boost public hygiene and impose strict infection controls in hospitals.
However, Dr. Bekedam of the WHO warns those efforts may not be enough. He says it is possible a second SARS outbreak could go undetected for months in China's remote rural areas. Impoverished rural residents will not be able to afford medical treatment, and the disease could then spread among the millions of workers who migrate from farms to the cities in search of jobs.
This story is part of VOA's 2003 in Review series