Humankind has had a lucky escape.114
Shortly before the isolation of the new avian-to-human H5N1 in Hong Kong in 2003, the WHO office in Beijing received an email warning that a “strange contagious disease” had killed more than one hundred people in Guangdong in a single week. Medical workers and foodhandlers were said to be especially affected. In the provincial capital of Guangzhou (Canton), panicked residents were buying up surgical masks and antibiotics as well as white vinegar, a traditional folk treatment for respiratory illness. Over the next few days, Chinese public-health officials grudgingly acknowledged that five people had died from “atypical pneumonia”; the outbreak had started in Foshan the previous November, had infected about 300 people, but was now “under control.” The Chinese were admitting, in effect, that they had concealed the epidemic from the WHO, but were now urging the world “not to worry”—they emphasized that the victims had all tested negative for influenza. But provincial and national authorities gave conflicting accounts of the likely pathogen: Guangdong blamed the bacterium Mycoplasma pneumoniae, while Beijing insisted that it was actually Chlamydia. To further erode credibility, “a spokesman for the Guangdong health department told reporters that all further information would be disseminated by the party propaganda unit.”115 Although these prohibitions did not stop the Internet from gushing rumors, authorities also threatened that “any physician or journalist who reported on the disease would risk being persecuted for leaking state secrets.”116
Veteran influenza researchers were highly skeptical of the official Chinese account. With avian influenza again killing birds in Hong Kong, it was logical to suspect that the mysterious pneumonia was, in fact, the beginning of the long-dreaded pandemic. The reports from Guangdong, moreover, were soon followed by the identification of the two, possibly three, human H5N1 cases: could this be just a coincidence? Circumstantial evidence supported the worst-case scenario. It also followed that if the disease were in Hong Kong, south China’s portal to the world, the virus might escape on the first available plane.
As investigators later reconstructed the itinerary, this is exactly what happened in the third week of February. A doctor from Guangzhou who had been attending victims of the pneumonia, arrived in Hong Kong on 21 February for a family wedding. Already ill, he checked into a room on the ninth floor of the Metropole Hotel, where by some unidentified mechanism, he managed to transmit his virus to sixteen other guests on the same floor—in the parlance of epidemiology, the doctor was a “superspreader.” As the infected hotel guests, including airline crew members, traveled onward to other destinations, they quickly transformed the Guangdong outbreak into an embryonic global pandemic. The CDC would later construct a flowchart of cases that originated from the Metropole Hotel: 195 in Hong Kong, 71 in Singapore, 58 in Vietnam, 29 in Canada, and 1 each in Ireland and the United States. As WHO Global Outbreak Alert and Response scientists later marveled, “A global outbreak was thus seeded from a single person on a single day on a single floor of a Hong Kong hotel.”117
The first Metropole case to attract WHO attention was a Chinese-American businessman who became desperately ill in Hanoi. Local hospital staff, petrified by the possibility that it was a case of avian flu, asked the local WHO representative, Dr. Carlo Urbani, to oversee the patient. The Italian doctor alerted the WHO Regional Office for the Western Pacific on 28 February that the mystery disease was now a traveler, and there were soon outbreaks in several other countries. On 1 March, with several patients already hospitalized in Hong Kong, a female flight attendant (the first of several Metropole victims) was admitted to a Singapore hospital with acute respiratory distress. A few days later, an elderly Canadian who had stayed in the Metropole died in Toronto, and five members of her family were soon hospitalized. Meanwhile, in a pattern that confirmed rumors from Guangdong, hospital workers who had been exposed to the Metropole patients in Hong Kong and Hanoi developed symptoms; the French Hospital in Hanoi was forced to close. Next, the Chinese-American businessman died, followed by the son of the elderly Toronto woman. By mid-March, scores of medical personnel in Hanoi and Hong Kong were in intensive care, and Ontario officials had to seal off Scarborough Grace Hospital. Dr. Urbani developed the disease and was evacuated from Hanoi to a hospital in Thailand, where he died on 29 March. By this time, some frightened hospital staff in China, Canada, and Vietnam refused to treat patients diagnosed with the enigmatic, deadly illness.
Was it avian influenza? The pathogen was still unidentified on 15 March when the WHO labeled the disease after its symptoms: Severe Acute Respiratory Syndrome or SARS. On that same day, a young Singaporean physician, returning from a medical conference in New York, was hospitalized during a stopover in Frankfurt along with his pregnant wife and mother-in-law. The doctor had treated the stewardess in Singapore: another superspreader, she would ultimately be the source of almost one hundred other cases. Although WHO finally issued a warning to the airline industry, it came too late to prevent other infected passengers from subsequently carrying SARS to Beijing and Taiwan. At the end of March, both Hong Kong and Toronto authorities were pressed to take more drastic action. Hong Kong officials closed schools and put more than 1,080 residents under quarantine, while in Toronto, another hospital was closed off and thousands of hospital workers and others in contact with SARS cases were asked to quarantine themselves at home.
In Hong Kong the epidemic assumed nightmarish proportions in the Amoy Gardens housing complex in Kowloon. Tower Block E was thirty-three stories high with eight apartments on each floor; the virus was first brought to the building in mid-March by a resident’s brother, who had recently undergone dialysis at the SARS-infected Prince of Wales Hospital. He was suffering badly from diarrhea and used his brother’s toilet. Within a few days, an extraordinary 321 residents of Block E and adjoining buildings developed SARS. The mode of transmission remains a mystery. Although some experts insist that the contagion had to be airborne (perhaps as residents shared elevators), Department of Health officials concluded that SARS was disseminated, at least in part, through faulty plumbing that brought residents “into contact with small droplets containing viruses from the contaminated sewage.” The Amoy Gardens incident was particularly troubling because it demonstrated that in conditions of extreme urban density—such as those found in high-rise housing, hospitals, and slums—viral transmission might be potently amplified by faulty ventilation and sewage systems, or, worse, by those systems’ absence.118
Meanwhile, SARS had become a test of China’s international credibility, with Health Minister Zhang Wenkang continuing to antagonize the world public-health community with his perfunctory and reliably inaccurate reports on the epidemic. Since early February, WHO experts had urgently wanted to visit Guangdong to investigate conditions there, but the Health Ministry obstructed the mission until the beginning of April—by then, SARS has set Beijing ablaze as well. China’s “official secrets” law had prevented Guangdong officials from briefing other local health authorities about the disease, so when the first cases appeared in Beijing in early March, local doctors were clueless. When the WHO team flew to Beijing, they were initially blocked from inspecting the military hospitals where most of the victims were being treated. Although officials continued to assert that the epidemic was contained, on 16 April WHO took the unprecedented step of chastising the Chinese government for “inadequate reporting” of SARS cases.119
Chinese leaders were deeply worried about the impact of the epidemic upon trade and economic growth. SARS, says Yanzhong Huang in a fascinating account, “caused the most severe socio-political crisis for the Chinese leadership since the 1989 Tiananmen crackdown.” China’s still-powerful former president, Jiang Zemin, reputedly urged strict censorship, while his successor, Hu Jintao, favored disclosure and collaboration with the WHO. Old-guard Beijing officials tried to conceal the full extent of the new epidemic not only from the outside world but even from high-ranking officials in the Zemin faction. When the WHO, for the first time in its history, advised visitors to stay away from Hong Kong and Guangdong, the Health Minister responded that SARS had been contained and that south China was completely safe for visitors. A courageous whistle-blower, a retired military surgeon named Jiang Yanyong who had treated many victims of the Tiananmen Square massacre, circulated an email that accused the minister of bald-faced lying.* Time magazine covered the story and, according to Huang, “triggered a political earthquake in Beijing.”120
President Hu Jintao and his supporters now took firm command of the situation: bureaucratic duplicity and inaction were replaced by an almost Maoist display of party-state willpower. The equivalent of 1 billion dollars in state aid (a fraction of the economic damage already caused to China and Hong Kong) was made available to upgrade local hospitals and public-health services. Health Minister Zhang Wenkang and Beijing Mayor Meng Xuenong—both Zemin loyalists—were purged, and other officials were bluntly told that their survival depended upon extirpating SARS. “Driven by political zeal, they sealed off villages, apartment complexes, and university campuses, quarantined tens of thousands of people, and set up checkpoints to take temperatures. . . . In Guangdong, 80 million people were mobilized to clean houses and streets. In the countryside, virtually every village was on SARS alert, with roadside booths installed to examine all those who entered or left.” To the surprise of many, these draconian quarantines—“momentous measures” says Yanzhong Huang—seemed to work. The spread of the SARS epidemic inside China was arrested, and in late June the WHO canceled its warnings about travel to Hong Kong and Beijing.121
While the drama inside China was unfolding, a WHO-organized virtual consortium of laboratories was working night and day to discover the cause of SARS. Within a month, this unprecedented research effort, spearheaded by Malik Peiris and his colleagues in Hong Kong and Shenzhen, had isolated a coronavirus. Although scientists were greatly relieved that it was not “the Big One” (an influenza pandemic) after all, they were flabbergasted that a member of a viral family normally associated with mild colds and diarrhea had become an international serial killer. And as researchers sequenced the genome of the SARS virus, they found little link to any of the known human-adapted members of the family. The SARS virus was genetically sui generis.
There was much speculation about an exotic animal source. Once again, the crack Hong Kong team led by Guan, Peiris, and Shortridge returned to the wet markets, this time in Shenzhen, the boomtown neighbor of Hong Kong. Among caged animals in the retail wildlife market, they soon found the SARS virus in a group of masked palm civets and a raccoon dog; a Chinese ferret badger also showed evidence of SARS’ antibodies.122 All three small carnivores are considered luxury or health items in the diet of Guangdong urban dwellers. (Ironically, civets are eaten because of a homeopathic belief that they provide immunity to influenza.) They are also lucrative commodities in the booming south China bushmeat trade that includes imports from Laos and Vietnam. SARS, then, like HIV, was a deadly by-product of a largely illegal international wildlife trade, intimately connected with logging and deforestation, which mortally threatens human health as well as regional biodiversity.123
The WHO officially declared the SARS outbreaks contained on 5 July. (A small-scale outbreak at the end of 2003, quickly controlled by Chinese authorities, reminded the world that SARS will be a recurrent danger until the prototype vaccine, now being field-tested, becomes widely available.) The first pandemic of the twenty-first century had generated approximately 8,500 cases in 26 countries; nearly 11 percent of SARS patients (916) died worldwide, although mortality in some localities was closer to 20 percent. Like influenza, SARS had a very strong preference for the elderly, whose death rate was over 50 percent. Young adults, in contrast, had only a 7 percent chance of dying, while SARS was seldom life-threatening to children.124
The management of the epidemic in Hong Kong and Toronto—each with an identical death rate of 17 percent—was the subject of investigation by expert panels in both cities. A summary of their respective findings was published in 2004 by the Journal of the American Medical Association (JAMA). As the panel chairs emphasize: “Both areas were hampered by underinvestment in public-health infrastructure, diminution of public-health leadership, and weak links between health care and public health.” In both cities, moreover, the health systems were overwhelmed by the epidemic. No one had expected a disease that targeted hospitals or took such a heavy toll on primary health-care personnel: 22 percent of SARS cases in Hong Kong, 43 percent in Toronto. Early in the Guangdong outbreak, some 90 percent of cases were among health-care workers. The Ontario government had to import, more or less clandestinely, several hundred U.S. doctors to make up the shortfall caused by ill or frightened physicians. In Hong Kong the hospital system almost broke down because of the lack of infection control in emergency rooms and the shortage of isolation units (single, negative-pressure rooms). In any event, JAMA reported, “neither jurisdiction had enough infection control practitioners and infectious disease specialists.” The distressing spread of SARS among medical personnel, however, was not due to the virus’s super-infectivity, but, rather, to surprisingly widespread failure of hospital staff to adhere to proper protective clothing and standard hygiene (such as simple hand-washing). In both cities, lines of authority were blurred or contradictory, and general practitioners were often left totally in the dark about diagnostic and therapeutic procedures. In the end, the nineteenth century, not the twenty-first, defeated SARS: “containment of SARS relied heavily on application of public health and clinical infection-control measures rooted in nineteenth-century science.”125
The laboratory manipulation of SARS also revealed dangerous flaws in the biosecurity of many research institutes and universities working with respiratory viruses. In separate incidents in Singapore and Taiwan, researchers managed to infect themselves with SARS. Robert Webster cited these cases in a January 2004 Lancet article in which he warned that an influenza pandemic might start with the escape of a dangerous fossil virus such as H2N2, the 1957 pandemic strain against which no one born since 1968 has any immunity. He reminded readers that the sudden reappearance of H1N1 in 1977, after a twenty-year hiatus, was probably the result of a lab accident in Russia or China.126
The SARS outbreak has also been studied as a real-life test of the preparedness of world organizations, national governments, and local health systems to respond to an influenza pandemic. “The quick and effective response of the WHO to SARS,” reported British experts to the Royal Society, “did much to restore faith among the many critics of the effectiveness of international agencies with large bureaucracies and limited resources for action.” But they warned that the successful containment of the SARS pandemic had sowed the illusion that the “system works,” when, in their view, the system was simply “very lucky.” The “simple public health measures that worked well for SARS” are “unlikely to be effective” in the case of an “antigentically novel influenza virus, of both high pathogenicity and transmissibility.” “Sentiments of the type ‘we have been successful once—we will be again’ may be far from the truth.”127
What are the key differences between SARS and influenza? Although SARS produces similar symptoms, it is not nearly as “subtle” as influenza.128 As Peiris and Guan emphasize, “SARS manifested several features that made it more amenable to control through public health measures than some other potential emerging infectious disease threats.”129 In the first place, SARS needs about five days to incubate and does not usually become contagious until well after the onset of fever and dry coughing; infectiousness takes about ten days to peak, and research has found few asymptomatic infections without sickness. The old-fashioned tactics of isolation and quarantine, if ruthlessly implemented, can work effectively against such a slow-developing virus whose symptoms consistently signal infectiousness.
Influenza is an altogether different story. It is fast and deceptive, and infectiousness and sickness do not coincide; an infected person massively sheds virus and becomes highly contagious a day or more before the actual onset of symptoms. (HIV, with its long, silent incubation period is, of course, even more insidious because the infected person can be contagious for years without manifesting any symptoms or sickness.) Moreover, influenza epidemics include large numbers of asymptomatic infections: spreaders without symptoms. Influenza, as a result, is more transmissible. In addition, technically it has a higher “R” or “basic reproduction number” (defined as the “average number of secondary cases generated by one primary case in a susceptible population”) than does SARS, or for that matter, HIV. A typical flu has an R of 5 to 25 while SARS is only 2 to 3 (not counting the still poorly understood phenomenon of so-called superspreaders). To stop an epidemic of SARS, public-health officials need only block viral transmission, either by isolation or quarantine, in about half the cases. Control of pandemic flu, on the other hand, requires an almost 100 percent containment of infection.130 Traditional isolation measures, accordingly, may not be much more effective tomorrow than they were in 1918.
Finally, the 2002–3 SARS pandemic had a fortuitous geography. China and Singapore were both authoritarian states with the capacity to impose effective, militarized quarantines. (In Singapore this took the Orwellian form of temperature-detecting sensors in the airport and home video-surveillance of hundreds of quarantined individuals.) Guangdong, moreover, by Chinese standards is a rich region with a much more modern health-care infrastructure than poorer inland provinces. Although SARS exposed the Achilles heel of neglect and underinvestment in their public-health systems, Toronto and Hong Kong are likewise affluent cities with superb laboratory medicine.
SARS in Bangladesh, Afghanistan, or Zaire would have been a different pandemic. This is exactly the “What if?” that haunted the Royal Society’s postmortem on the SARS pandemic: “[S]uppose the virus had flown from Hong Kong to Durban instead of Toronto. It is a city of similar size but without a similar health infrastructure, and with a significant proportion of its inhabitants immune-compromised owing to HIV-1 infection. Then Africa could have become endemic for SARS by now.”131 An influenza pandemic, to be sure, would not neglect the poor countries of the world.
* The ever doughty Jiang was subsequently arrested in June 2004 after circulating a letter asking the government to apologise for the Tiananmen massacre.