HANOI, Vietnam -- Before he became the host suspected of carrying from southern China the deadly illness that continues to nettle health officials around the world, American [Johnny Chen (born 1954)] was an ordinary man concerned with the business of making blue jeans.

On Monday morning, Feb. 24, it was business as usual for Mr. Chen and colleagues from the Shanghai office of Gilwood Co., a small New York garment firm. He had made the short trip to Vietnam from Hong Kong the day before with a simple mission: make sure Gilwood's local contractor, the Hung Yen Garment Co., or Hugaco, on the outskirts of Hanoi, was properly stitching zippers and other accessories on jeans due for export in April.

Mr. [Johnny Chen (born 1954)], whose business card identified him as Gilwood's garment merchandise manager based in Shanghai, looked happy and healthy that day as he checked samples and had lunch before returning to Hanoi, says Chu Huu Nghi, deputy-director of Hugaco's export-import division. There was no hint that the jovial, 49-year-old Chinese-American would soon take ill with a wicked bug -- which still hasn't been identified -- that would kill him two weeks later and elicit a rare global health warning from the World Health Organization.

So far, Mr. Chen's 10-day Vietnam visit has had a serious impact on the country: Health officials believe his illness spread directly and indirectly to 63 confirmed and suspected cases in Vietnam, most of them health workers and their families. A Vietnamese nurse succumbed to the mystery illness.

The toll in Vietnam now accounts for almost a third of the global count of confirmed and suspected cases that has grown in just a few weeks to more than 200 on four continents. Hong Kong, where the cases have also occurred mostly among doctors, nurses and other hospital staff, now counts 123 cases, the most anywhere.

With the blue-jean manufacturing line appearing in fine working order that first morning on the ground in Vietnam, Mr. Chen and his colleagues returned to Hanoi that afternoon. Local Gilwood employee Nguyen Bao Thuy says she then took Mr. Chen to do a little shopping. They looked at denim material in the busy Hom market on Hue Street and bought some clothes for Mr. Chen's personal use at a shop called Thang Long on Ngo Quyen Street.

[ Note ... As of Oct 7 2021, the first person who shows for "Nguyen Bao Thuy" is "https://www.linkedin.com/in/bao-thuy-nguyen-38541410/" ... who is a biotechnology patent officer .. example includes https://www.freepatentsonline.com/6794152.html ]

That night, Mr. [Johnny Chen (born 1954) hit the town to partake of Hanoi's bustling night life. Neighbors later recalled a stranger -- it was Mr. Chen -- who returned to Gilwood's office about 11 p.m.

On this visit to Hanoi, Mr. Chen chose to stay in a bedroom atop Gilwood's office, a now-shuttered, four-story, light-blue building with turquoise trim overlooking the city's Ngoc Khanh lake, according to Ms. Thuy. His colleagues from Shanghai, including Kenny Liu and two Chinese nationals, stayed at Hanoi's Daewoo Hotel.

The next morning, Feb. 25, Mr. Chen was feeling a little rough. He had lunch that day with Mr. Liu and their Chinese colleagues at the Daewoo coffee shop overlooking the hotel's pool. After eating, Mr. Chen complained of chills. He went out to buy some medicine and headed back to the office. Ms. Thuy says Mr. Chen told her he thought he just needed an early evening to shake the bug.

He turned in early that night. A concerned colleague arranged for a local doctor to make a house call on Mr. Chen early the next morning, Wednesday, Feb. 26. The doctor recommended rest.

Mr. [Johnny Chen (born 1954)] told his colleagues he wasn't feeling strong enough to make another planned trip to Hugaco that morning. Mr. Liu, Ms. Thuy and the others went to the factory without him. When they returned to Gilwood's office later that day, they found Mr. Chen sprawled on his bed with a high fever, clearly in distress.

They hustled him to the capital's lone international hospital, the Hanoi French Hospital. The hospital's staff couldn't identify the pathogen involved but quickly determined they had a serious case on their hands and contacted both the World Health Organization and the U.S. Embassy. After a week of unsuccessful treatment, Mr. Chen was evacuated on March 5 to Hong Kong by private plane at the request of his family. He died eight days later.

At Gilwood's Hong Kong office, a single, bare-walled room where corduroy pants with Nautica labels hang on racks, office head Simon Ho remembers the last time he saw his late colleague. It was on March 7, through a glass window at the Princess Margaret Hospital's Intensive Care Unit. Mr. Chen, whom Mr. Ho had known as sturdy and jocular, lay apparently unconscious with tubes protruding from his body and a respirator doing his breathing.

Mr. Chen's wife, Lisa, who had come from her home in New York, was also there. She occasionally peered through the glass at her husband and sobbed, at times inconsolably, he said. "The doctors said they didn't know what was causing it," Mr. Ho said. The Hong Kong Health Department has declined comment on individual cases of the illness.

Mr. Ho's sadness turned to apprehension as it became clear that Mr. Chen's illness had led to the infection of dozens of health-care workers at the Hanoi hospital where he was treated. Worried he too was at risk, he went to see a doctor. "I saw the TV reports and began to get scared. I've gone in for X-rays," he said. "They didn't turn up anything; I'm healthy."

Mr. Chen's illness hasn't spread to personnel at the Hong Kong hospital where he succumbed; most of the recent Hong Kong cases have been linked to another man who had traveled to southern China before he became ill and who was treated at a different hospital, Hong Kong health officials say.

Mr. [Johnny Chen (born 1954)] potentially infectious trail during his last days is a continued source of worry not only to health officials, but also to employees at Gilwood concerned that they also may have been infected. But, like Mr. Ho, most fellow workers who came into contact with Mr. Chen before he was hospitalized appear to be unaffected by the disease.

Gilwood's Hanoi office is a small operation, employing a Filipino quality-control manager, Roberto Pedragosa; a part-time administrator, Nguyen Duc Ngoc; Ms. Thuy; two security guards; a driver; and a 42-year-old maid, Chu Thi Phuong.

[ Roberto Pedragosa : " https://cn.linkedin.com/in/roberto-pedragosa-31469a30?trk=people-guest_people_search-card " actually worked for Klaus Steilmann GmbH & Co. Kg and not "gilwood" ]

Ms. Phuong, who regularly cleaned the office and also visited Mr. Chen in the hospital, has exhibited some of the same symptoms as Mr. Chen. She is currently in the state-run Bach Mai Hospital in Hanoi, which is treating several people that the World Health Organization considers to have only unconfirmed cases of the disease it calls severe acute respiratory syndrome, or SARS. Ms. Thuy says that Ms. Phuong "feels better now." Ms. Phuong couldn't be reached for comment.

For her part, Ms. Thuy says she came down with a bad headache and cold flashes after Mr. [Johnny Chen (born 1954)]'s visit, but says she now feels better. As a precaution, Vietnamese health officials have instructed her to remain home for an indefinite period. Mr. Ngoc says he is healthy. Mr. Liu, back in Shanghai and not responding to calls or visits seeking comment, hasn't developed any flu-like symptoms common to SARS cases, says Gilwood President Charles Haigh in a telephone interview from his home in New York City.

The health status of the two Chinese nationals who traveled with Mr. Liu couldn't be immediately learned.

To date, there are no cases at the Hugaco factory of SARS. The Hung Yen provincial department of health visited the factory last week. One official there says there have been no reported cases of SARS in the province's 13 hospitals.

Mr. Pedragosa, 43, Gilwood's quality-control manager in Hanoi, became so worried after Mr. Chen fell ill that he flew home to Manila on March 10 via Ho Chi Minh City (where several cases have since been reported). "I told him not to fly on a plane, but he just wanted to go home he was so scared," said Mr. Haigh.

Mr. Pedragosa, who couldn't be located for comment, was discharged Monday from Manila's Medical City General Hospital, where he had undergone observation and treatment for diarrhea, according to local health officials. He will remain under observation at an undisclosed health facility for another 10 days, they said, but he hasn't developed symptoms of SARS.

Mr. Haigh, who says he and his colleagues are cooperating fully with the World Health Organization and the U.S. Centers for Disease Control and Prevention in Atlanta, says Mr. Chen didn't travel to Hanoi from his Shanghai base, but from Hong Kong where he spent "five or six days." He says of the potentially fatal disease, which officials believe has an incubation period of a week or less: "I think Johnny picked it up in Hong Kong."

Whatever the case, Mr. Chen's demise is having a lasting effect on Gilwood, a company Mr. Haigh began 10 years ago to export garments from Asia. The company came to Vietnam less than six months ago, lured like many other companies big and small by a bilateral trade accord with the U.S., which came into effect in December 2001.

"People are walking into our Shanghai office with masks on, like it's the plague," says Mr. Haigh, nursing a bad cold he attributes to lack of sleep and the stress of the past two weeks. "We've lost three weeks of production over the past month over this; this is really hurting my business."

-- Peter Landers in New York contributed to this article.

1. SOUNDBITE (English) Doctor [Dr. John S. MacKenzie (born 1943(est.))], Team leader and virologist from the University of Queensland in Australia:   "We hope it will be very productive from both sides. From the global perspective - in terms of knowing more about SARS - but also from the more local perspective, shall we say, in terms of us providing whatever information we can, whatever help we can to our colleagues here in China."

2. Pan from Dr Meirion R. Evans, UK epidemologist (left) and [Dr. Wolfgang Preiser (born 1965)], German virologist to Dr Robert F Breiman, US Infectious disease specialist (left) and MacKenzie

3. SOUNDBITE (English) [Dr. John S. MacKenzie (born 1943(est.))], Team leader and virologist from the University of Queensland in Australia:   "We've had 27 suspected cases in Australia but it's only information of the sort we're getting now - I mean, like we've been getting for the last three weeks - that we've been able to say that those 27 suspect cases in Australia are not SARS. And sure they've travelled in the right place. Sure they've got atypical pneumonia but they're not SARS under the current case-definition. So to be able to find out what the best definition possibly is, is incredibly important."

4. SOUNDBITE (English) Dr Robert F Breiman, American Epidemiologist and Infectious disease specialist:  "In the case of Legionnaires disease and (unclear) virus - and there have been many other emerging diseases - there is plenty of evidence that those diseases existed before. What's made it recognised is the actual clustering, it's the epidemic."

5. SOUNDBITE (English) Dr James H. Maguire, Chief of epidemiology, US National Centre for Infectious Diseases, Centres for Disease Control and Prevention:   "It may be, it may not be but it may be that what we learn, what is learned here in China will provide the key. There may be issues here. The fact that if this was really the first location for where these diseases occurred, there may be some reasons why that happened here that I think are gonna be very interesting to explore."

STORYLINE:   A team of World Health Organization (WHO) experts said on Monday they were analyzing the cases of Chinese sickened in an outbreak of a fatal flu-like illness in hopes of finding out whether it is linked to a mystery disease that has spread to three continents. The five-member team arrived on Sunday and said they would examine Chinese records this week.  They said they had not decided whether to visit the southern province of Guangdong, where five deaths from atypical pneumonia were reported. WHO says it is treating the outbreaks as part of the same emergency that has killed 10 people in Hong Kong, two in Vietnam and two in Canada, though it isn't clear if the deaths were caused by severe acute respiratory syndrome, or SARS. Another 305 people also were sickened in Guangdong since the first cases were reported in November, Chinese health authorities say. The Chinese government didn't report the outbreak until February and its reluctance to release information fueled a panic in Guangdong and neighboring Hong Kong.  People bought up supplies of antibiotics and vinegar for use as a disinfectant. Cases of SARS have also been confirmed in Europe.

The first case of the flu-like disease Severe Acute Respiratory Syndrome (SARS) was confirmed in Germany on Tuesday. A 72-year-old man who recently traveled to Hanoi, Vietnam and Singapore was diagnosed as having the illness by the Bernhard Nocht Institute for Tropical Medicine in Hamburg.

The man is being treated at a clinic in the town of Hemer in southwestern Germany (photo). He is already on his way to recovery, the clinic announced on its Web site. "The patient no longer has a fever or suffers from any other conditions." The man will be kept in quarantine until tests confirm that he is not contagious, the clinic wrote.

Four other people are thought to have SARS in Germany, while there are twelve suspected cases, according to the Robert Koch Institute, which is largely responsible for monitoring public health in the country.

German doctors are working closely with the World Health Organization (WHO) and clinics worldwide to find out what causes the disease and how it can be stopped. SARS has already killed 61 people, mainly in China and Hong Kong, and it has spread throughout Asia, Europe, North America.

Control may be possible

The German states have established a surveillance system to deal with any outbreaks of the disease. The Robert Koch Institute has announced that the patients in Germany suspected of having SARS are all in quarantine. International airports have posted announcements in English and German to alert passengers traveling to or from Asia to be aware of the symptoms of the disease and get medical attention if they suspect they may have contracted it.

The Bernhard Nocht Institute has warned the public not to panic. SARS is not as infectious as influenza, Director Bernhard Fleischer said in an interview with the Berliner Zeitung newspaper on Tuesday. Furthermore, the disease can only be contracted through close contact with infected people. That suggests that it may be controllable, Fleischer said.

Virologist Christian Drosten, also from the Hamburg institute, told the Süddeutsche Zeitung newspaper that one would have to be coughed on by an infected person to contract SARS. The disease is transmitted through exhaled droplets and bodily secretions.

Fatal in few cases

SARS is highly contagious, comparable to the Ebola virus that stemmed from monkeys and was responsible for hundreds of deaths in Africa in the 1990s, according to the World Health Organization. Virologist Drosten said the SARS disease is fatal for 4 percent of patients, while the Zaire strain of Ebola kills 90 percent of the people who contract it.

On Monday, a WHO spokesperson said the world body was close to identifying the cause of SARS. "We can identify the causative agent within a few days, but we are not sure if we can develop the cure in such a short time, Hitoshi Oshitani, regional advisor on communicable diseases, told a press conference in Manila, Philippines." WHO established an international research project consisting of eleven labs in ten countries on March 17 to find the virus that causes SARS.

Origin in Asia

According to the WHO, the first case of the disease was reported in Hanoi, Vietnam in late February. In Guangdong, China, however, investigation is underway to determine whether an outbreak of "atypical" pneumonia in November 2002 was linked to the appearance of SARS. Researchers fear that farmers' livestock in the southern Chinese province may have infected humans.

The main symptoms of SARS are high fever (above 38°C/ 100.4°F), a dry cough, shortness of breath or breathing difficulties. It has an incubation period of two to seven days. To avoid transmitting the disease, patients are put in quarantine.

Over 1,600 cases of SARS have been reported worldwide. International travel is responsible for the disease's spread throughout the world. Cases have been reported in 15 countries, including Britain, France, Italy, Ireland, Romania and Switzerland.

When the microbe that causes severe acute respiratory syndrome is finally isolated, some people will know what to call it. They want a Latin variation on Carlo Urbani's name.

If SARS was an infectious cloud blowing out of southern China, [Carlo Urbani (born 1956)] was the canary in its path. Working in a hospital in Hanoi, Vietnam, as a mysterious pneumonia felled one nurse after another, he sang out the first warning of the danger, saw the world awaken to his call -- and then died.

If not for the intuition of Dr. Urbani, director of infectious diseases for the Western Pacific Region of the World Health Organization, the disease would have spread farther and faster than it has, public health officials around the world say.

It was a tricky call. There is nothing as telltale about the disease as the bleeding of a hemorrhagic fever or the bumps of a pox, and its symptoms mimic other respiratory conditions.

[Carlo Urbani (born 1956)], 46, died on March 29, a month after seeing his first case and 18 days after realizing he was coming down with the symptoms himself.

''Carlo's death was the most coherent and eloquent epilogue his life could produce,'' said Nicoletta Dentico, a friend from the Italian chapter of Médecins Sans Frontières, or Doctors Without Borders, which Dr. Urbani once headed. ''His death was as a giver of new life.''

And it was in keeping with his medical philosophy. When Dr. Urbani spoke in 1999 at the ceremony in which Doctors Without Borders accepted the Nobel Peace Prize, he described doctors' duty ''to stay close to the victims.''

''It's possible to study an epidemic with a computer or to go to patients and see how it is in them,'' said Dr. William Claus, the group's emergency coordinator for Asia. ''Carlo was in the second category.''

In Italy, he had pushed the organization into working with the poorest of the poor, with Gypsies in Rome and with African and Albanian boat people who were landing in Sicily and Calabria.

Even as a student, said Fabio Badiali, a childhood friend who is now mayor of Castelplanio, their hometown on the Adriatic Coast, he had been a volunteer, organizing groups to take the handicapped on countryside picnics. As a family doctor, he had taken vacations in Africa, traveling with a backpack full of medicine.

He had accepted the W.H.O. post, friends said, because he wanted to be back in the third world and working with patients. It was that instinct that took him to the bedside of [Johnny Chen (born 1954)], an American businessman who entered Vietnam-France Hospital in Hanoi on Feb. 26 with flulike symptoms.

Dr. Urbani might not have been an obvious choice as a consultant in Mr. Chen's case. In his heart, friends said, he was ''a worm guy,'' a specialist in parasites.

''Other people didn't think worms were sexy,'' said Dr. Kevin L. Palmer, W.H.O.'s regional specialist in parasitic diseases and a friend. ''But it's a really basic problem for every child in the tropics.''

Dr. Urbani was an expert in Schistosoma mekongi in Vietnam, in the food-borne nematodes and trematodes of Laos and Cambodia and the hookworms of the Maldives.

Dr. Lorenzo Savioli, who worked with Dr. Urbani in the Maldives, said they worked from sunup to sundown, ignoring the famous beaches and reefs, tracking hookworm epidemiology and training workers at a malaria control laboratory, who were used to working with blood, in testing for worms. Over rice and fish in the evenings, Dr. Savioli said, they had joked, ''Nobody at headquarters was going to believe we were spending our days in the Maldives over fecal samples.''

Dr. Urbani was a worm zealot, Dr. Palmer said, because they did so much damage but could be so easily treated. For example, he said, a 3-cent pill administered to schoolchildren twice a year could rid them of most intestinal worms. Dr. Urbani was working to have school systems in southeastern Asia cooperate.

He also attacked a worm that lived on fish farms. He could not get Cambodians and Laotians to give up eating undercooked fish, Dr. Palmer said, but he hoped to solve the problem by teaching fish farmers to divert sewage from their ponds.

He was also testing the use of a veterinary drug to kill worm larvae that can reach human brains and cause seizures.

And, said Daniel Berman, a director of the Doctors Without Borders campaign for cheaper lifesaving drugs, Dr. Urbani was pushing Vietnamese farmers to grow more sweet wormwood, a plant that can produce artemisinin, a new malaria cure.

Still, when a troublesome case turned up in Hanoi, Dr. Palmer said, the W.H.O. staff usually said, ''Call Carlo,'' because he was also known as an expert clinical diagnostician.

Mr. Chen was such a case, suffering with pneumonia and fever, as well as a dry cough. The hospital suspected that he had the Asian ''bird flu'' that killed six people in 1997 and was stopped by rigid quarantines and the slaughter of millions of chickens and ducks.

Rumors of a mysterious pneumonia had been coming out of the Guangdong region of southern China, but the Chinese authorities had been close lipped, even instructing local reporters to ignore it.

Although no one then realized the significance, Mr. Chen, 48, had also stayed in the Metropole Hotel in Hong Kong. He may have picked up the disease from a 64-year-old Guangdong doctor in town for a wedding, staying in Room 911. Investigators theorize that the doctor infected 12 other guests, several from the same floor, who carried the disease to Singapore, Toronto and elsewhere.

By the time Dr. Urbani arrived at Vietnam-France Hospital, the microbe that Mr. Chen carried was spreading. Before he died, he infected 80 people, including more than half of the health workers who cared for him. The virulence of his case alarmed world health officials, helping lead to the extraordinary health alert that W.H.O. issued on March 15.

But Dr. Urbani, who first saw Mr. Chen in late February, quickly recognized that the disease was highly contagious and began instituting anti-infection procedures like high-filter masks and double-gowning, which are not routine in impoverished Vietnam. Then he called public health authorities.

Dr. Palmer recalled Dr. Urbani's conversation: ''I have a hospital full of crying nurses. People are running and screaming and totally scared. We don't know what it is, but it's not flu.''

On March 9, Dr. Urbani and Dr. Pascale Brudon, the W.H.O. director in Hanoi, met for four hours with officials at the Vietnam Health Ministry, trying to explain the danger and the need to isolate patients and screen travelers, despite the possible damage to its economy and image.

''That took a lot of guts,'' Dr. Palmer said. ''He's a foreigner telling the Vietnamese that it looks bad. But he had a lot of credibility with the government people, and he was a pretty gregarious kind of character.''

With dozens of workers at the hospital sick, it was quarantined on March 11. Infection-control practices were instituted at other hospitals, including the large Bach Mai state hospital, where Dr. Claus of Doctors Without Borders oversaw them.

Dr. Urbani's quick action was later credited with shutting down Vietnam's first outbreak.

In the middle of it, Dr. Savioli said, Dr. Urbani had an argument with his wife, Giuliani Chiorrini. She questioned the wisdom of the father of three children ages 4 to 17 treating such sick patients.

Dr. Savioli said Dr. Urbani replied: ''If I can't work in such situations, what am I here for? Answering e-mails, going to cocktail parties and pushing paper?''

In an interview with an Italian newspaper, Ms. Chiorrini said her husband knew the risks. ''He said he had done it other times,'' she recalled, ''that there was no need to be selfish, that we must think of others."

But on March 11, as he headed to Bangkok for a conference on deworming schoolchildren, he started feeling feverish and called Dr. Brudon.

''He was exhausted, and I was sure it was because he had had a lot of stress,'' Dr. Brudon said later. ''I said, 'Just go.' ''

But she had second thoughts. ''I called my colleagues in Bangkok and said, 'Carlo doesn't feel well, and we should be careful.' ''

[Dr. Scott Ferris Dowell (born 1963)], a disease tracker for the federal Centers for Disease Control and Prevention, who is based in Thailand, met him at the Bangkok airport near midnight. Dr. Urbani, looking grim, waved him back. They sat in chairs eight feet apart until an ambulance arrived 90 minutes later, its frightened attendants having stopped for protective gear.

For the first week in a Bangkok hospital, Dr. Urbani's fever receded, and he felt a bit better. But he knew the signs. ''I talked to him twice,'' Dr. Palmer said. ''He said, 'I'm scared.' ''

That was uncharacteristic for a man who was known as big, charming and full of ironic wit. In Italy, he staved off boredom by hang gliding. In Hanoi, he negotiated the insane traffic on a motorcycle and took his children on overnight car jaunts to rural villages. He carried Bach sheet music and stopped at churches, asking if he could play.

W.H.O. experts flew in from Australia and Germany to help. One scoured Australian drug companies for ribavirin, a toxic antiviral drug that was said to have helped some cases. It did not help Dr. Urbani, though, and was withdrawn.

Then patches showed up on a lung X-ray, and he told his wife to take the children and return to Castelplanio. Instead, she sent them ahead and flew to Bangkok.

By the time she arrived, his room had been jury-rigged as an isolation ward. Carpenters had put up double walls of glass, and fans had been placed in the window to force air outside.

The couple could talk only by intercom, and Ms. Chiorrini saw him conscious just once. As his lungs weakened, Dr. Palmer said, he was put on a respirator.

In a conscious moment, Dr. Urbani asked for a priest to give him the last rites and, according to the Italian Embassy in Bangkok, said he wanted his lung tissue saved for science.

As fluid filled his lungs, he was put on a powerful ventilator, sedated with morphine.

The end came at 11:45 on a Saturday morning. Doctors and nurses heavily shrouded in anti-infection gear pounded on his chest as his heart stopped four times, [Dr. Scott Ferris Dowell (born 1963)] said, but it was useless.

Most of those who had died of SARS were old or had some underlying condition that weakened them, but ''he worked with patients for weeks, and we suspect he got such a massive dose that he didn't have a chance,'' Dr. Palmer said.

''It's very sad,'' Dr. Claus said, ''that to raise awareness as he did, you have to pay such a price.''

BERLIN -- A German biotech company began distributing on Monday what it says is the first commercial test for a respiratory virus that has killed over 140 people and infected more than 3,300 worldwide, ravaging parts of Asia.

Hamburg-based Artus said it had developed the test for the virus causing Severe Acute Respiratory Syndrome, or SARS, with the nearby [Bernhard Nocht Institute for Tropical Medicine] in just two weeks and had begun distributing it free

"We have had a wave of demand.... We are providing it free of charge. It is an urgent medical need," Artus's marketing director Kay Koerner told Reuters, adding that the company may later seek financial gain from the test.

The test can detect the virus from throat swabs, sputum or feces and produces results in two hours, say its makers, who specialize in disease test kits. They said classical tests for antibodies typically took 10 to 20 days after infection.

Koerner said Artus had already sent test kits to a number of Asian countries, and laboratories in Australia, Germany and Scandinavian countries were also being supplied.

Artus, which has subsidiaries in Malaysia and the United States, is not stock market listed. It was set up as an independent company by the BNI [, aka Bernhard Nocht Institute for Tropical Medicine].

German microbiologist []Dr. Bernhard Fleischer (born 1950)], head of the BNI, said late last month that his institute had probably identified the virus causing SARS.

Scientists believe it is caused by a new coronavirus, a relative of one of the many viruses that cause the common cold. SARS is marked by a high fever, dry cough and other flu-like symptoms, and can progress to pneumonia.

About four percent of patients with SARS die, scientists say.

In late February, Olivier Cattin, a doctor at the Hanoi French Hospital in Vietnam's capital, found himself stumped by the case of an American businessman with a fierce respiratory illness. He knew just whom to call: [Carlo Urbani (born 1956)].

The outgoing, 46-year-old Italian was a physician with the World Health Organization. He was well-known in Hanoi's close-knit medical community as a skilled diagnostician who loved good food and organ music and was devoted to his work de-worming Vietnamese schoolchildren.

Dr. Cattin's hunch was that his patient, [Johnny Chen (born 1954)], was suffering from some sort of avian flu. He had heard reports of a mysterious flu outbreak in southern China, where Mr. Chen had been. But Dr. [Carlo Urbani (born 1956)], after examining the patient on Feb. 28, wasn't sure. Those doubts would balloon into dread as 10 hospital employees quickly contracted the mystery illness soon to be known as severe acute respiratory syndrome.

Alarmed, Dr. Urbani and his colleagues at the Hanoi WHO office harangued Vietnam's rigid communist bureaucracy and helped spur its aggressive measures to contain SARS. When Hong Kong reported its own eruption, officials at WHO's Geneva headquarters had heard enough. On March 12, the agency issued a rare world-wide health alert.

At a time when the effectiveness of multilateral approaches to global problems has become a hotly debated subject, the SARS saga so far reflects well on one United Nations bureaucracy. The disease remains mysterious and could still prove devastating. But by taking a zero-tolerance approach to the disease with governments as disparate as China and Canada, the WHO may well have limited the toll of SARS at the crucial early stage.

"Say what you will about U.N. agencies, but here's a group that acted forcefully and quickly," says Dr. Jeffrey Koplan, the former head of the U.S. Centers for Disease Control and Prevention in Atlanta.

The WHO's decisions haven't been easy. It angered Toronto officials when it slapped a short-lived travel advisory on the city after a nurse there took SARS to the Philippines. It urged people to avoid Hong Kong and southern China, chilling corporate travel to the world's hottest destination for investment dollars and badly damaging the regional economy. Its careful probing of Beijing hospital wards made liars of senior Chinese officials who tried to conceal the extent of the disease within its borders -- and got sacked. At the same time it drew criticism for moving too slowly to publicly criticize Chinese authorities.

The WHO has no regulatory or police powers. Its chief asset is highly motivated people such as Dr. [Carlo Urbani (born 1956)] and the personal relationships they cultivate in corners of countries many diplomats never see. These crucial ambassadors sometimes pay the ultimate price: Dr. Urbani died of SARS in a Bangkok hospital after raising the critical red flag in a war that is now seeing its first apparent victories. Earlier this week, the WHO declared Vietnam, the country he loved, free of SARS.

Established in 1948, the WHO's mission is to improve international health -- whether by mass vaccination campaigns, helping countries respond to outbreaks, or by acting as a clearinghouse of information. For years the WHO had a reputation as an often slow-footed bureaucracy, especially when it came to emerging diseases. By the time the WHO hosted its first meeting on the international implications of AIDS in November 1983, the disease had already been reported in 33 countries on five continents.

When AIDS surfaced, "we were completely unprepared," says Dr. Guenael Rodier, director of the WHO's Department of Communicable Disease Surveillance and Response. "We reacted in a noninnovative way by slowly building a program" instead of trying to prevent the virus from spreading world-wide.

People inside the WHO say Director General Gro Harlem Brundtland, 64, deserves credit for making the agency more responsive and relevant. Previous directors had included good doctors and technocrats, but Dr. Brundtland, a former prime minister of Norway, brought new political clout to the organization when she took over in 1998.

Under her stewardship, the WHO has pushed drug makers to make AIDS drugs cheaper for poorer countries, has made significant strides in ridding the world of polio and is now going after "life-style" diseases -- heart disease, obesity, diabetes and certain cancers -- that are rapidly becoming the planet's biggest killers.

"She got health off the back burner and made it a globalization issue," says Jim Palmer, a Washington-based consultant to the WHO.

One of WHO's longtime assets is privileged access, through high-level government contacts in its 192 member states, to the health authorities in most of the world's countries. That access would prove critical when Dr. Urbani alerted his superiors on Feb. 28 to what was happening in Hanoi.

At that time, Dr. Keiji Fukuda, chief of epidemiology for the influenza branch at the CDC, and [Hitoshi Oshitani (born 1959)], a WHO officer based in Manila, were in Beijing looking into reports out of southern China of an outbreak that resembled an extremely deadly strain of avian influenza known as H5N1. But the Chinese were stonewalling, blocking a trip to Guangdong in the south and restricting the two doctors to meetings with health officials in Beijing.

COMBATING GLOBAL DISEASE : Key milestones in the World Health Organization's history: (Source: WHO)

• April 2003: Oversees network of labs that identifies a coronavirus as the cause of SARS. Forces China to concede it has more cases than it previously admitted. The WHO declares Vietnam to be SARS-free.

• February 2003: Finalizes landmark treaty to stem tobacco use and related deaths globally; it is expected to be adopted in May.

• 2002: Announces with partners that through eradication efforts, countries with new cases of polio declined to seven from 125 in 1998.

• Late 1980s: Working with Unicef, reaches record childhood-immunization rates of more than 80%.

• 1980: Certifies the eradication of smallpox.

Then Dr. [Carlo Urbani (born 1956)] called from Hanoi.  Dr. [Hitoshi Oshitani (born 1959)] urged him to collect blood and respiratory samples. Maybe Mr. [Johnny Chen (born 1954)] was suffering from H5N1. Yet the disease didn't resemble avian flu in its symptoms or transmission patterns. Every test for the influenza had turned up negative.

Meanwhile, the disease was rapidly affecting health-care workers at the Hanoi French Hospital. Dr. Urbani and his boss in Hanoi, 57-year-old Pascale Brudon, decided they needed to enlist the government's help to contain the bug.

By Friday, March 7, the bureaucratic feedback wasn't good: Officials might meet with them on Monday. The WHO officials worked the phones and finally reached Nguyen Van Thuong, vice minister for health. At a four-hour meeting on March 9, the WHO officials argued that the new disease merited systematic preventive measures and outside backup.

But Mr. Thuong got a different message from Vietnamese experts, who believed the disease was influenza type-B and, being limited to one hospital, not particularly worrisome. The talks grew heated, Ms. Brudon recalls. Ultimately, Mr. Thuong sided with the WHO -- a pivotal decision that would place Vietnam and China in stark contrast.

By Monday, March 10, evidence of a potential pandemic was gathering. The mystery disease had cropped up unmistakably in Hong Kong and Toronto. That day, Dr. [Carlo Urbani (born 1956)] called Dr. Klaus Stohr, the WHO's influenza-project leader, in Geneva. Dr. Stohr, who is German, recalls him saying, "We're losing control of the hospital," referring to Hanoi French Hospital.

Hours earlier, Hong Kong's health director, Dr. Margaret Chan, received a call from an official at the city's hospital authority who said that an unusually high number of health-care workers at Prince of Wales Hospital were calling in sick with flu-like symptoms. On March 12, local investigators told Dr. Chan the situation was serious. That afternoon, she called the WHO in Geneva.

Officials there quickly met to decide whether the WHO should issue a global health alert. It was a tricky decision. The last time the WHO had issued such an alert was in 1994, when plague had reappeared in India.

"We wondered: 'Are we mad? Are we going to panic the world?' " recalls Mike Ryan, an amiable Irishman who coordinates the WHO's Global Alert and Response team.

That evening, the WHO issued the alert. The main victims at that point were health workers -- the most vital group needed to deal with the outbreak of an infectious disease. Moreover, "the cause was unknown, we had no clue where it came from and people were dying like flies," Dr. Stohr says. By issuing such an alert, the WHO was essentially asking its member countries to warn their citizens about the atypical pneumonia, and also suggesting they, too, gear up for a potential outbreak.

The alert provoked immediate response -- and some criticism. Health ministries of several countries "asked us why we hadn't informed them first," says Denis Aitken, Ms. Brundtland's right-hand man.

More cases appeared. China, where officials suspected the disease originated, was the most worrisome site. The WHO wanted to send in experts, but Chinese officials put them off, citing an important national political meeting lasting through March 18. "It's never been different," says Dr. Stohr, who in the past had to deal with Chinese authorities over flu outbreaks.

As he and others mulled how to crack the China problem, the stakes were suddenly raised halfway across the world early on Saturday, March 15.

At 2 a.m., Geneva time, Dr. Ryan was awakened by a phone call from Dr. Oshitani's boss in Manila. "He said something important was going down in Singapore," recalls Dr. Ryan. A health official in Singapore reported that a 32-year-old Singapore doctor, who had treated the country's first two mystery-pneumonia patients, had boarded a flight from New York City to Singapore. Shortly before stepping on the plane -- a Boeing 747 carrying 400 people representing 15 nationalities -- he had described his own symptoms to an alert medical colleague in Singapore, who notified health officials.

At 8 a.m., several WHO specialists in Geneva, clad informally in T-shirts and jeans, held a series of impromptu, emergency meetings in a room converted into a war room to plot the agency's next move. They were a hard-core, experienced bunch. Dr. Rodier, a Frenchman who was Dr. Ryan's boss, had buried Ebola-stricken corpses in Uganda. [Dr. David Lowell Heymann (born 1946)], the American head of the WHO's communicable-diseases group, had headed to the Congo in 1995 to contain a deadly outbreak of Ebola. He rushed back from a camping trip to make the meeting.

They decided to quarantine the 400 Singapore Airline passengers in Frankfurt, an intermediate stop. That decision may have proved crucial in preventing the spread of the disease more widely across Europe. "Ten years ago, without mobile phones and e-mail, you couldn't have done this," says Dr. Ryan.

The next key question: Should the WHO issue a rare global travel advisory -- a decision that would have huge implications for world business and tourism. Dr. Heymann pushed hard for the alert, but some others objected. "What if we're wrong?" Dr. Stohr recalls one person saying.

As the hours went by, everyone had become convinced they had a new and deadly pathogen on their hands, and it was spreading ominously via air travel across the world. "Before we were saying, 'Be careful.' With the travel alert we were saying, 'This is a crisis,' " says Dr. Stohr.

With a draft of the news release ready, Mr. Aitken suddenly said: "What are we going to call it?" This was a subtle, but important issue: By giving the disease a name, the WHO would be telling the world that it was something new, something to be feared.

Someone suggested "atypical pneumonia of unknown cause," but that was rejected because the word "unknown" might scare people. Finally, Dick Thompson, a former science journalist and now press officer for the WHO, nailed it. "How about: 'severe acute respiratory syndrome?' " he asked. SARS case definitions and recommendations to hospitals and airlines quickly followed.

As the disease continued to spread in Hong Kong, Vietnam, Singapore and Canada, public annoyance was mounting over China's silence about the extent of its infection. The WHO was going to have to get tougher. But it would be Monday, March 24 before a WHO team of five experts arrived in Beijing for their first meeting with Chinese health officials.

At first, it looked as though the WHO might face a replay of the frustrated mission led by Dr. Oshitani a month earlier. The team's Chinese counterparts were lower-level health officials. The setting -- with microphones on either side of the table and white-gloved women pouring tea -- was formal and awkward.

WHO inspectors were champing at the bit to get to Guangdong, according to Dr. James Maguire, an epidemiologist and infectious disease specialist from the CDC. But the Chinese asked them to put together lectures for delivery the next day on general topics such as pneumonia and histories of infectious-disease epidemics.

"I guess the conclusion of that meeting was: We were off to a slow start," says Dr. Maguire, who participates in continuing WHO investigations in Beijing.

The next morning the WHO team prodded the Chinese to be more forthcoming, and the Chinese "came through," says team member, [Dr. John S. MacKenzie (born 1943(est.))]. That afternoon and during the next couple of days, Chinese officials provided detailed data on the outbreak in Guangdong that had begun in November. But the WHO team was still left with big questions.

The Chinese officials wouldn't provide them with any data about the situation since February, except to repeat that the situation was "under control," according to the WHO team. The officials also seemed wedded to the notion that the outbreak was caused by a rare respiratory strain of chlamydia bacteria, which had been found in a few of the patients. They seemed uninterested in mounting data that the disease was being caused by a coronavirus -- a theory later affirmed by the WHO. Chinese Health Ministry officials did not respond to questions for this article.

On Friday, March 28, the WHO team pressed for access to Guangdong. Dr. MacKenzie said the message was explicit: "If SARS is not under control in China, there would be little chance of controlling the global threat of the disease." After more frustrating delays, the WHO team members were finally told late on April 2 that they could leave immediately for Guangdong.

Meanwhile, rumors were flying about scores of hidden cases in Beijing. On April 3, Health Minister Zhang Wenkang went on television to announce there were only 12 cases in the capital and the disease was under control. That conflicted with press reports days later of a letter from a prominent Beijing surgeon, Dr. Jiang Yanyong, accusing the health minister of covering up scores of cases.

On April 8, the WHO team met with the health minister and Vice Premier Wu Yi to inform them of their findings in Guangdong. Dr. Henk Bekedam, the WHO's full-time representative in Beijing and a natural diplomat, did much of the talking.

He told the officials that Guangdong had put in place a strong system to cope with disease, including tracing potentially infected people, updating numbers of cases, and instituting infection-control procedures at hospitals. But he delivered a blunt message regarding the situation in Beijing. "I said the international community does not trust your figures," Dr. Bekedam says.

It wasn't until April 16, though, at a news conference where foreign reporters chastised the WHO team for evading questions about whether Beijing was covering up SARS cases, that team members finally made their criticism of the Chinese government public. Alan Schnur, a WHO official who had defended the government's handling of SARS, stated the team's estimate that there were 200 probable cases of SARS in Beijing, and a further 1,000 people under observation as possible patients -- far more than the official tally of 37 cases.

Shortly after that, senior leaders, including President Hu Jintao and Prime Minister Wen Jiabao, appeared on television warning of punishment for any officials attempting to cover up SARS cases. The following Sunday, the health minister and the mayor of Beijing were sacked, and the city announced there were nearly 10 times as many cases in the city as the official tally suggested.

Asked if he thought events would have moved more quickly had the WHO made its criticism public at an earlier stage, Dr. Bekedam said working on Beijing officials privately was the WHO's chosen strategy and didn't mean that the agency had "lowered the bar for China."

[Johnny Chen (born 1954)] was a hard-driving American businessman based in Shanghai, used to making things happen. So he was dispirited, even angry, when, after a visit to Hong Kong, he became fatigued and feverish and wound up in a hospital bed here.

Chen checked into Hanoi French Hospital, the city's only private hospital, in late February with a 104-degree fever, a sandpaper cough and muscle aches that would alarm an Italian parasitologist, [Carlo Urbani (born 1956)], who would alert the world to a strange, new respiratory disease.

By the time [Johnny Chen (born 1954)] died on March 13, four days after his 49th birthday, it was clear to a group of health care experts that the businessman was the victim of a new disease. A day earlier, the World Health Organization had put out a global alert.

But on April 28, just six weeks after Chen died, Vietnam's government was able to declare the country the first in the world to contain severe acute respiratory syndrome, or SARS.

It would appear unlikely that a poor communist country could become the first to tame a mysterious, contagious disease. But Vietnam's handling of SARS is a tale of decisiveness, cooperation and luck, in which early detection and strong infection-control measures under the guidance of international experts gave Vietnam an edge.

In Hong Kong, [Johnny Chen (born 1954)] had stayed at the Metropole Hotel, where he is believed to have been infected by a Chinese doctor who picked up the virus treating sick people in southern China.

Chen, a merchandise manager for a New York garment manufacturer, had come to Vietnam to visit a factory that produced jeans and shirts for his company. He was hospitalized on Feb. 26 with body aches, and he coughed and coughed.

Olivier Cattin, a hospital doctor, thought that perhaps Chen had picked up avian flu in Hong Kong.

Two days later, Vu Koang Thu, a doctor at the hospital, called the World Health Organization and reached [Carlo Urbani (born 1956)], WHO's communicable diseases expert in Vietnam. Urbani looked at X-rays of Chen's chest and advised the hospital to take blood samples and throat swabs, which were sent to WHO collaborating labs in Tokyo and the Centers for Disease Control and Prevention in Atlanta, and the National Institute for Hygiene and Epidemiology in Hanoi.

One night, wracked by pain, he cried, awakening a patient two doors away. The next day, a Saturday, [Johnny Chen (born 1954)] was told that he needed his blood drawn, but he insisted that "only a French doctor prick him," Thu said. A French doctor assured him that would be the case. Chen closed his eyes, and a Vietnamese nurse plunged the needle into his arm. He never knew.

By that Sunday, Chen could not breathe. His lung X-rays were completely white, a sign the lungs were inflamed, infected or filled with fluid. He was moved to an intensive care unit and hooked to a ventilator, sedated so that he would not fight the machine.

On March 4, his wife arrived from Hong Kong. On March 5, an international medical evacuation company flew him to Hong Kong. He died there seven days later in Princess Margaret Hospital.

[Carlo Urbani (born 1956)] and [Hitoshi Oshitani (born 1959)], a WHO communicable disease expert from Manila, began to suspect that there might be a connection between the illness in Hanoi and an atypical pneumonia epidemic in Guangdong province in southern China, news of which was trickling out.

On March 7, alarmed by Urbani's daily reports of mounting infections among health care workers, WHO activated its Global Outbreak Alert and Response Network, a grouping of public health specialists who stand ready to respond to outbreaks around the world.

Urbani and Pascale Brudon, WHO's Vietnam representative, asked for a meeting with Vietnamese health officials. Urbani and Brudon worked the phones furiously, calling various officials.

The Vietnamese officials agreed to meet March 9 at the Health Ministry. At first, they were not convinced of the problem's severity because their lab tests showed that the virus was influenza B, and not thought to be linked to the outbreak in China. Besides, the infections were limited to one hospital, WHO officials recalled. But Urbani explained that the disease was very contagious and dangerous.

But by the end of the two-hour meeting, the vice minister of health, Nguyen Van Thuong, had agreed to allow WHO to summon an international team of experts. He also promised to organize a task force at the ministry that would review the situation daily.

It was, Brudon said, a "turning point."

Vietnam's response contrasted with that of China, which for weeks tried to conceal the extent of its outbreak. But a health official in Vietnam, Le Thi Thu Ha, said her country made a simple calculation: "We needed that technical assistance," she said.

On March 12, two WHO team experts visited the Hanoi French Hospital to help the doctors and nurses there halt the disease.

In the parking lot, 15 members of the health care staff, in surgical masks, advanced on the pair, eager for answers about the disease that was making their colleagues deathly ill.

"They kept converging upon us," said Tim Uyeki, an epidemiologist with the CDC who had flown in from Atlanta. The two experts kept backing away, hospital officials said.

"It was surreal," a doctor said.

That week, the Health Ministry set up a task force. Days later, a dozen epidemiologists and pathologists had arrived from Britain, the United States, Sweden, Germany, France and Australia.

"You need a heap of people to chase the cases, read the notes, find out what's going on, respond to new things, help set up new measures," said Aileen Plant, the WHO coordinator for the SARS expert team. "Are you following the contacts? Are you putting infection control in place? What are you going to do with a dead body? Can people breast-feed? All of these sorts of things, you've got to think about really fast."

Meanwhile, Urbani was scheduled to attend a meeting in Thailand. Before he left, he called Brudon from the airport, saying he felt feverish. She told him it was probably just fatigue -- he had been working 16-hour days for 10 days. He flew to Bangkok. He was admitted to a hospital there, and died on March 29.

Urbani was not the only medical worker to be infected. On the day that [Johnny Chen (born 1954)], the American, left the hospital, four doctors and nurses were admitted as patients. The next day, seven more followed. By Tuesday, March 11, two dozen health care workers were in the hospital -- one-quarter of the health care staff.

The situation was tense, staff members recalled. The hospital caterer refused to provide food. People rode by the three-story building on motorbikes with their shirts held over their mouths. When doctors crossed the street to buy a pack of cigarettes, shopkeepers would turn them away.

"It was very, very stressful," said Nguyen Nang Tan, 36, a doctor who also was admitted to the hospital. "I thought that everyone could get sick and die."

On March 15, Nguyen Thi Luong, the nurse who had tended to Chen, died.

On March 19, Jean Paul Derosier, the anesthetist who had put Chen on a ventilator, died.

On March 24, gynecologist Nguyen The Phuong and nurse Nguyen Thi Uyen died.

On April 12, Nguyen Huu Boi, an orthopedist, died.

Most of the Vietnamese doctors and nurses who remained healthy wound up sleeping at the hospital, because of fears that they could spread the infection. Effectively, they isolated the virus at its most infectious point, health experts said.

"So you ended up with the situation where they probably infected each other much more than would have happened in some communities, where they might have been at home and infecting their families -- not all of them, but quite a lot, enough of them, to change the chances of infection" to the broader community, said Plant.

Hanoi French Hospital stopped admitting new patients on March 11. But it kept its own ill staff, finally shutting its doors on April 12, the date of the last patient's death. The hospital has been decontaminated and is slated to reopen in June.

Vietnam began an extensive effort to find everyone who had contact with a SARS patient, a process health workers call "contact tracing." Most cases involved only health care workers and their immediate family. In one instance, however, a man whose daughter underwent surgery at Hanoi French Hospital became infected. He lived in Ninh Binh province, 44 miles from Hanoi. Vietnamese health care workers located 128 people who had had contact with him. "We asked them to stay at home," said Ha, the health official. "Our health care staff came to visit them every day, for 14 days."

The Vietnamese task force eventually designated Bach Mai's Medical Institute for Tropical Diseases as the SARS facility. WHO and CDC officials were alarmed when they saw that Bach Mai was accepting SARS patients even before the facility was properly equipped. It lacked N-95 respirator masks to protect against SARS. As is the custom in Vietnam, family members continued to flock to patients' rooms to feed, bathe and help care for their ill relatives.

But WHO and the CDC quickly donated masks, gowns and other equipment. Japan contributed similar supplies and two ventilators. Doctors Without Borders, an international group of volunteer medical professionals, sent a team to help. Workers were trained in infection control techniques.

Doctors at Bach Mai said the hospital's lack of air conditioning forced them to throw open doors and windows, which they said helped contain the virus by dispersing any particles that might otherwise adhere to surfaces and people.

More important, WHO officials said, the patients admitted to Bach Mai by and large were not as sick as those at Hanoi French. And unlike other countries, in which more than one patient passed the disease on to others, all of Vietnam's 63 cases, including 36 health care workers, can be traced to Chen.

"There's a bit of luck here," Ha said.

Vu Khac Khoan, 76, and Nguyen Duc Khiem, 67, Vietnam's final two SARS patients, were released Friday from Bach Mai Hospital, which became the main SARS facility. At a memorial service in Hanoi, the World Health Organization's Tran Cong Dai bows before a photo of Carlo Urbani, a physician who alerted the world to SARS. Vu Koang Thu, a doctor at Hanoi French Hospital, in the room that was occupied by Johnny Chen, an American businessman who died of SARS.Vu Khac Khoan, who recovered from SARS while at Bach Mai Hospital, claps in appreciation of the doctors and nurses who cared for him. He was released from the hospital on Friday.

It seemed like the typical viral ''summer cold'' as it began spreading through a nursing home in the Vancouver area in early July. Then in August, test results from the Canadian National Microbiology Laboratory suggested that the ''cold'' might be from a mutated SARS coronavirus.

Just the hint created deep concerns in a country that had already been hobbled by an outbreak in Toronto last spring. British Columbia officials temporarily imposed infection control and quarantine measures that had contained the Toronto outbreak.

The disruptive and costly actions turned out to be excessive. British Columbia officials have since determined that the SARS coronavirus did not cause the outbreak. Rather, they said, its virological cousin, the OC43 coronavirus, which commonly causes colds, was the probable culprit.

Disputes among Canadian officials over the virological findings have exposed deep flaws in the systems available to detect and monitor any potential outbreak in Canada and elsewhere. Not only did they underscore the need for more uniform laboratory testing, but also prompted health officials to renew calls for reliable tests to detect SARS, or severe acute respiratory syndrome, in its earliest stages of infection.

''The safety net for detecting the possible return of SARS is pretty fragile,'' said Dick Thompson, a spokesman for the World Health Organization, the United Nations agency in Geneva with responsibility for controlling the disease. ''It holds together, but it is spit and luck.''

Examination of the disputed findings in Canada is also occurring as the world is bracing for the possible resurfacing of SARS. A recent report from the United States National Intelligence Council -- which consists of experts from the academic and private sectors and which reports to the director of central intelligence, George J. Tenet -- lays out three bleak possible situations for the virus's re-emergence. Surprisingly, the intelligence report does not consider an instance in which the disease does not reappear.

The three situations outlined in the report are disconcerting. One is a resurgence in countries with major trade centers as international travelers spread SARS the way they did this year. A second is that SARS cases will occur sporadically but will be detected before the disease can spread, creating more of a public health nuisance than a crisis. The third unfolds in developing countries with weak public health systems.

All make early detection a priority. Canadian and United States health officials and SARS experts are expected to discuss what steps may reliably be taken to identify possible new SARS cases, among other topics, at a two-day closed meeting in Ottawa that begins tomorrow.

To some health officials, the outbreak at the Kinsmen Place Lodge nursing home in Surrey, British Columbia, has not only revealed important gaps that need to be addressed, but it may also provide lessons that can be used in the face of a recurrence of SARS.

''In a way, it was lucky that this outbreak happened before the influenza season because it is better to learn about the problems now than then,'' said Dr. Katrin Leitmeyer, a W.H.O. epidemiologist and virologist who went to the National Microbiology Laboratory in Winnipeg to review its findings.

One of the most glaring problems uncovered by the nursing home outbreak was the absence of a formal agreement among scientists about precisely what steps and laboratory methods should be used to make a definitive diagnosis of SARS.

For example, many test results remain in dispute, largely because the scientists involved in different laboratories did not use the same methods to test each specimen to try to identify the virus and to determine whether the patients' immune systems had produced antibodies against it. And partly because little is left of the specimens collected from the nursing home patients, it will take weeks more to prove that the suspected OC43 coronavirus, is the cause.

The conflicting laboratory results have led Canadian scientists and officials to clash over the validity and meaning of the tests performed on the lodge residents and staff members.

''We're at loggerheads with the National Microbiology Laboratory,'' said Dr. Mel Krajden, the chief virologist at the British Columbia Center for Disease Control.

The center's chief epidemiologist, Dr. David Patrick, said that from July 1 through August, 95 of the 142 lodge residents, or 67 percent, developed the summer cold and that 8 deaths were related to the outbreak. Of the 160 health workers there, 53, or 33 percent, developed the summer flu.

Initially, Dr. Krajden's team found no evidence of viruses like influenza, parainfluenza and respiratory syncytial virus that are common causes of upper respiratory illness.

SARS was low on the candidate list because the death rate among lodge residents was 8 percent, far lower than the rate of 50 percent or more found among people 60 and older in the SARS epidemic last spring.

But when a second wave struck the nursing home and the center still could not identify a virus, health officials reconsidered SARS. ''So, having come up empty-handed, we said why not send some of the very limited remaining materials to'' the national laboratory, Dr. Krajden said.

It was a step that many laboratories less concerned about the threat of SARS might not have taken under the same circumstances, health officials said.

The surprise came when [Francis Allan Plummer (born 1952)], the director of the National Microbiology Laboratory, said that his team had found tentative evidence of what might be a mutant SARS virus.

Then on Aug. 22, provincial officials said the latest findings from the British Columbia Center for Disease Control and the British Columbia Cancer Agency's Genome Sciences Center ''provide conclusive evidence'' that the virus responsible for the nursing home outbreak was not the SARS coronavirus, but probably its cousin, OC43.

''We have clearly found large sequences of the virus that are not present in the SARS coronavirus,'' Dr. Patrick said.

Last week, Dr. Larry J. Anderson, an expert on respiratory diseases at the Centers for Disease Control and Prevention in Atlanta, said his team had completed tests to detect antibodies to the SARS virus in the blood specimens sent by Dr. Plummer. The C.D.C. tests did not confirm the Canadian National Microbiology Laboratory findings that SARS antibodies were present.

Dr. Plummer said he agreed that the virus was not the classic SARS virus, but that his team had found no evidence of OC43.

''We do not dispute their results, but we also believe our results,'' Dr. Plummer said. ''Now what produced them is a puzzle.''

Among the possible explanations for the conflicting results is that two or more viruses were simultaneously affecting the nursing home. Another possibility is that the specimens from the lodge were inadvertently contaminated with SARS virus in the Winnipeg laboratory. Dr. Plummer said he considered that unlikely because of the pattern of his test findings. ''All these diagnostic tests are new and every laboratory has developed its own test,'' he said.

''We have a limited understanding of their performance, so comparing what one laboratory is talking about to another is problematic,'' Dr. Plummer said. ''This is obviously new territory for all of us. We are probably at a normal state of development for a disease that has been around for a few months, and we will be learning every time one of these things happen.''

The Canadian laboratories have not succeeded in growing the nursing home virus and then fully mapping its genome -- two findings that would provide the most definitive evidence of the causative agent. But virologists say that growing the coronavirus apparently involved in the nursing home outbreak is more difficult than growing the SARS virus in the laboratory.

The threat of SARS may prompt several changes in laboratory practices, virologists said. For example, diagnostic laboratories rarely include coronaviruses in screening tests for the cause of outbreaks of respiratory illness because they generally cause mild illness and because budgets preclude searching for every virus.

''No one ever cared that much,'' said Dr. Kathryn V. Holmes, a professor of microbiology at the University of Colorado Health Sciences Center in Denver who has studied coronaviruses for 20 years. She was not involved in the Canadian investigation.

And the nursing home developments raise questions about how research is conducted in a public health crisis, said Dr. Roland Guasparini, chief medical health officer of the Fraser Health Authority near Vancouver, which had jurisdiction over the nursing home outbreak.

[Dr. John S. MacKenzie (born 1943(est.))], an Australian virologist who is temporarily helping W.H.O. deal with the threat of SARS and other emerging diseases, said the nursing home episode pointed out three major worries about laboratory testing for SARS that an advisory panel of W.H.O. would need to address in October.

One is the lack of quality assurance. The various methods have not been tested in different laboratories under different conditions, Dr. MacKenzie said, and ''this is a big concern.''

Second, there is no internationally accepted standardization of the biological materials known as reagents used in testing in different laboratories. Dr. MacKenzie said he was particularly concerned about the lack of standardization of the control tests, which play a routine part in laboratory testing.

Third, Dr. MacKenzie said, ''we need to look very carefully at what we do if we have a positive case.''

''What's crucial is that a second laboratory, preferably an international reference laboratory outside the country that found the positive, confirms the tests,'' Dr. MacKenzie said. ''Some countries are not keen on this,'' he added, yet ''it is a major issue.''

At the October meeting, he said, ''We're going to go into detail about what is known, what isn't known, what needs to be done, and then prioritize some things that need to be looked at.''

But because the W.H.O. meeting will not be held until late October, it may be too late to be effective, Mr. Thompson, the agency spokesman, acknowledged.

By then the Northern Hemisphere may be experiencing the usual seasonal outbreaks of influenza and other respiratory illnesses. Under such circumstances, the continuing lack of a reliable diagnostic test for SARS could create chaos from the continuing inability to distinguish SARS from other illnesses that, by coincidence, were producing similar symptoms like fever, headache and cough.

An expert panel convened by the World Health Organization called on all countries yesterday to stringently oversee laboratory safeguards, to prevent another escape of the SARS virus like the incident that infected a research worker in Singapore in August.

If laboratory safety standards are not strengthened, ''the whole world can be vulnerable'' to another SARS epidemic, said [Dr. John S. MacKenzie (born 1943(est.))], an Australian microbiologist who attended the meeting in Geneva.

All countries should conduct inventories at their laboratories to determine where the SARS virus is being kept and what strains of the virus are being stored, Dr. MacKenzie said. Also, Dr. MacKenzie said, the World Health Organization, an agency of the United Nations, and member countries need to develop procedures to control which laboratories can hold and work with the virus, which at present apparently only exists in laboratories.

Angus Nicoll, director of communicable disease surveillance for Britain's health protection agency and the meeting chairman, said the committee members asked whether all laboratories were meeting the correct safety standards. ''The answer is probably not,'' Dr. Nicoll said in a telephone news conference.

The W.H.O. invited 45 international experts in public health, SARS, virologists, social sciences, laboratory science and other disciplines to meet for the first time to identify the most important gaps in knowledge about SARS, or severe acute respiratory syndrome.

The committee came up with a list of the highest priority research questions for researchers, but did not specify what the issues were. In the case this summer, a 27-year-old doctoral student accidentally became infected with SARS while working on the West Nile virus in a laboratory in Singapore. The student did not know he had been exposed to the SARS virus.

A W.H.O. committee that investigated the Singapore case identified flaws in laboratory procedures and concluded that the student became infected in the laboratory. The committee found that the West Nile virus had been contaminated with the SARS virus.

Besides laboratory safety, another priority on the committee's list is determining which animals, if any, are the sources in nature of the human SARS virus.

Although scientists in Hong Kong and China have found the SARS virus in exotic animals sold in markets in Guangdong Province, they have not determined whether the animals were infected in the wild or contaminated in the market.

''One of the very important research priorities will be to identify the animal reservoir, if there is one, from China,'' said Dr. Joseph Sung of the Chinese University of Hong Kong and Prince of Wales Hospital there.

Scientists have found evidence of SARS infection among animal handlers in the market. But, Dr. Nicoll, the British expert, said, ''we don't know quite what it is that they're doing that puts them particularly at risk.''

W.H.O. has held many meetings on SARS, but the two-day meeting that ended yesterday was the first to include social scientists. They recommended that researchers now try to determine the common misperceptions, myths and institutional hurdles that caused fear among the public and impeded control of SARS.

Health officials need to learn good ways to avoid confusion in informing the public about what is known and unknown about SARS, because there were many myths about how an individual could and could not catch SARS, participants said.

Social scientists also recommended additional research to help health officials deal with Chinese and other groups that were vulnerable to stigmatization in the SARS epidemic.

Dr. Jong Wook Lee, the director general of the World Health Organization, assured the committee that the agency would devote more money for SARS, if needed. But, Dr. Nicoll said, ''we are wary'' about the the agency's ability to deal with SARS and other epidemics of new and old diseases.

''We have learned a lot in the past year, but one of the things we have learned particularly is that we very much need W.H.O. for this kind of emergency,'' Dr. Nicoll said.

An independent scientific advisory panel convened by the World Health Organization yesterday recommended against routine testing for the SARS virus unless a cluster of cases develops and all other infectious agents have been ruled out.

The panel plans to soon publish a guideline for doctors and laboratories to follow to determine when to test for the SARS virus. Except for a laboratory worker who became infected, no case of the disease has been detected since the early summer when the W.H.O., a United Nations agency in Geneva, said the epidemic was over and transmission had stopped .

If a laboratory does come up with a positive test result for SARS, it must send the specimens to a second laboratory that belongs to the W.H.O. network for independent validation of the findings, said [Dr. John S. MacKenzie (born 1943(est.))], an Australian microbiologist who organized the science panel's meeting in Geneva this week.

Unless there is such confirmation, the United Nations agency will not list any country as SARS-infected, Dr. MacKenzie said in a telephone interview from Geneva.

If a major outbreak of SARS, or severe acute respiratory syndrome, occurred, then the system of sending specimens for independent confirmation would become less critical, said [Dr. Joseph Sriyal Malik Peiris (born 1949)] of the Queen Mary Hospital in Hong Kong. W.H.O. credits Dr. [Malik] Peiris with discovering the SARS coronavirus.

W.H.O. said it recognized the risk that SARS might spread if tests were delayed. ''We admit that we might well miss the first case or even the first cluster,'' Dr. MacKenzie said.

The panel, he said, is recommending limiting SARS testing for now largely because scientists do not have enough specimens of the serum portion of blood from patients who were infected during the epidemic earlier this year. The serum contains antibodies to the virus and is needed for purposes of scientific controls in diagnostic testing.

Laboratory scientists ''need positive serum to make quite sure that what you're seeing is what you expect to see,'' Dr. MacKenzie said.

But, Dr. MacKenzie said, the agency also is trying to prevent other risks, like a flood of unnecessary testing and false alarms.

''No lab test is perfect,'' he said, and the lack of serums for testing ''is a major problem.''

False positive test findings are more likely to occur when a disease is not occurring, and they would set off immediate time consuming, cumbersome and costly public health action. That includes isolating patients, tracing their contacts and imposing quarantines.

The panel's concern grows out of a situation in Canada this summer when the national laboratory initially said it had detected the SARS virus among residents of a nursing home near Vancouver. But a SARS laboratory at the United States Centers for Disease Control and Prevention in Atlanta did not confirm the findings.

[Dr. Joseph Sriyal Malik Peiris (born 1949)] said that the panel was now recommending a number of steps to double-check the first positive result, at the initial laboratory. The steps include conducting a different test, using another specimen from the same patient and retesting the original specimen.

Serum from infected patients is in short supply because the amount of blood that doctors remove for SARS tests is far smaller than what is needed for supplying laboratories around the world. To generate a larger supply, scientists in a number of countries are recruiting patients who have large amounts of SARS antibodies, Dr. Peiris said.

During the epidemic, some individuals whose serums were rich with SARS antibodies had donated blood as an experimental treatment known as passive immunization for very ill SARS patients. Such donations are relatively easy to obtain because they are altruistic. But, Dr. Peiris said, ''when you talk about donating blood for diagnostic tests it seems a bit more remote.''

SARS is one of many viruses that can cause a lung condition known as atypical pneumonia, and many doctors would be likely to suspect SARS because of the epidemic earlier this year. But, Dr. MacKenzie said, ''we don't want to test everyone who has atypical pneumonia unless there is a cluster of cases for which there is no other alternative diagnosis and for which antibiotics do not work.''

A possible exception is when staff members in intensive care units develop atypical pneumonia. A large number of health care workers developed SARS in the initial phases of the epidemic earlier this year.

The number of infections from the deadly coronavirus continues to grow to more than 64,000 cases around the world. And on Tuesday, a British businessman was identified as a “super spreader” of coronavirus (someone who infects an unusually large number of people) after he contracted the disease in Singapore and then traveled through multiple countries in Europe, infecting at least 11 others along the way.

This recent case has already drawn comparisons to multiple instances of super spreaders infecting large groups of people with another respiratory disease, severe acute respiratory syndrome (SARS) during that disease’s outbreak in 2003. Health officials at the time identified five different super spreaders who helped the spread of the SARS outbreak that infected over 8,000 people, killing 774 of them.

One of those cases involved a Chinese respiratory doctor who spread the disease to seven other people during a one-night hotel stay in Hong Kong. Those seven people all happened to stay on the same floor of the same hotel as the super spreader, Dr. Liu Jianlun, before several of them traveled to other countries, helping to give the disease a larger global footprint.

Now, roughly 17 years later, that hotel is still remembered as the infamous ground zero for one of the worst global disease outbreaks of the century.

Spreading SARS

In February 2003, then 64-year-old Dr. Liu Jianlun checked into Room 911 of what was then known as the Metropole Hotel, a 487-room, three-star hotel located in Hong Kong’s Kowloon district, according to the WHO’s chronology of events.

Liu had been working in a hospital in Southern China where SARS patients were being treated and he’d started developing some respiratory symptoms a few days before traveling to Hong Kong for his nephew’s wedding, The Washington Post reported in May 2003. But after his chest x-ray came back clear, the doctor decided he was clear of the disease and healthy enough to travel.

At that time, the SARS outbreak had been mostly contained to mainland China, but Liu would unknowingly help the disease spread to multiple new countries and continents.

By the time Liu checked out of the hotel after just one night, he’d already infected seven other people, all of whom also stayed on the Metropole’s ninth floor. (Some investigators believed that Liu might have either coughed or vomited in the ninth floor hallway and that’s how the disease spread to other guests on his floor.)

Among them were a Chinese-American businessman who left the Metropole hotel to fly from Shanghai to Hanoi, Vietnam. That man, Johnny Chen, would die in a Hanoi hospital within a month after passing on the SARS virus to several members of the hospital staff, the BBC reported.

Another guest of the Metropole’s ninth floor was a 78-year-old Canadian tourist who returned to Toronto a few days later and died less than two weeks after that, ultimately spreading SARS to roughly 60 more people in Canada and also killing her 44-year-old son, according to The Globe and Mail.

Other guests infected by Liu included three women from Singapore who also stayed on the ninth floor and contracted the disease before taking it back to Singapore. The three women were all soon hospitalized and ultimately survived, but one of them reportedly spread the disease to roughly 195 people.

Liu himself never made it to his nephew’s wedding, instead checking himself into Hong Kong’s Kwong Wah Hospital the day after he arrived in the city. He remained in the hospital until he died less than two weeks later. He also infected one doctor and five nurses, all of whom eventually recovered, according to the Post.

The WHO eventually estimated that roughly 4,000 of the world’s total SARS cases (about half) during that outbreak could be traced back to Liu’s stay at the Metropole Hotel. News reports around the world named the hotel as a SARS hotspot and a ground zero for the disease that spread across the globe after Liu’s stay.

Metropole no more

Today, the hotel remains open but it operates under a different name. It’s now called the Metropark Hotel Kowloon and the hotel’s website unsurprisingly contains no references to the 2003 SARS outbreak.

CNBC Make It reached out to the hotel’s management for comment and did not receive a reply.

In 2003, the hotel’s manager reportedly contemplated the idea of turning either Room 911, where Liu stayed, or even the entire ninth floor into “a museum” memorializing the SARS outbreak, but that never came to pass, according to local newspaper the Taipei Times. (In fact, the Taipei Times even reported in 2004 that the hotel had renumbered some of the rooms on the ninth floor so that what would have been Room 911 had been changed to Room 913.)

Despite the changes, the hotel’s ties to history haven’t seemed to escape people’s memories, as multiple posts on Tripadvisor have mentioned the fact that the hotel’s name changed in the wake of the SARS outbreak nearly two decades ago.

In 2009, another Hong Kong hotel owned by the Metropark’s management company dealt with the fallout of a guest bringing the city’s first reported case of the H1N1 virus to Hong Kong, resulting in a quarantine of the hotel’s 300 guests, according to CNN.

“Revenue loss and image damage is a concern,” Benny Ng, an operations manager for the hotel chain told CNN at the time. “When an incident like this happens, obviously, it will have a little impact on the business.”

Ng also noted at the time that neither the H1N1 or SARS outbreaks were caused by anything the hotels did “and has nothing to do with the hygiene or the facilities of the property.”

Infection hotspots today

Today, health officials around the world are on the lookout for hotspots where multiple cases of the current coronavirus, or COVID-19, are popping up in one location. Dozens of people were evacuated from the same apartment building in Hong Kong this week after multiple residents were found to be infected, and Chinese authorities quarantined 10,000 people in the city of Tianjin after tracing one-third of the city’s coronavirus cases to a single department store, according to The New York Times.

And COVID-19 super spreader Steve Walsh, the aforementioned British businessman, contracted the coronavirus at a conference at Singapore’s Grand Hyatt hotel in January before traveling to France, where he spread the disease to multiple fellow guests at a ski chalet in the French Alps.

As of Friday, cases of COVID-19 have been discovered globally in roughly 28 countries. So far, there are only 15 confirmed cases of the disease in the U.S. The Centers for Disease Control and Prevention says the best way for people to avoid infection includes washing your hands frequently and avoiding close contact with people who are sick.