by The Pandemic Century- One Hundred Years of Panic, Hysteria
ONCE SCIENTISTS had cracked SARS’s genetic code and established it was a coronavirus, the next obvious question was to ask where it had come from. The two types of coronavirus previously known to infect humans belonged to groups that typically infected mammals and birds. SARS, however, did not appear to belong to either of these groups. Still, it was likely that SARS had zoonotic origins and that its animal host was probably located in Guangdong, where the earliest cases had occurred. As several of those cases had been traced to chefs and seafood merchants, the obvious places to look were the markets where restaurants bought exotic animals for their clientele.
In May 2003 Peiris’s colleague Yi Guan packed a satchel with syringes, swabs, and sample vials and set off by train for Shenzhen’s Dongmen Market. There, working with the Shenzhen Centers for Disease Control, Guan approached animal traders and asked to take nasal samples and fecal swabs. Those who demurred were reassured that if any animal died they would be compensated up to the sum of 10,000 Hong Kong dollars (about $6), but more often than not Guan was able to anesthetize the animals and take samples on the spot. As you might expect, there was a wide array of animals on sale: raccoon dogs, Chinese ferret badgers, beavers, Chinese hares, and Himalayan palm civets. At the end of two days, Guan had collected twenty-five samples. They showed that four out of six of the palm civets carried a coronavirus that was 99.8 percent genetically identical to the human coronavirus. In addition, one of the raccoon dogs carried the same virus as the civet cats, while one ferret badger had antibodies to the virus. When the animal viruses were sequenced, they were found to have a short section of twenty-eight nucleotides that were missing in the human virus, leading Guan and his colleagues to conclude that it was the absence of this sequence, or perhaps a random mutation, that had enabled the virus to transmit easily between humans. Moreover, 40 percent of the animal traders whose blood was tested and 20 percent of those involved in slaughtering the animals had antibodies to the virus carried by the civet cats, indicating that the virus had probably been circulating between animals and market traders for some time without causing disease. Even though other researchers were not immediately able to replicate Guan’s findings, the Chinese halted sales of fifty-four species of wild animals while further tests were conducted in other markets. Those tests also found evidence of SARS antibodies in traders who dealt in palm civets, suggesting that the virus was regularly passing from animals to humans in southern China. However, it did not resolve the question of where the virus normally resided in nature. Nor did it explain why the SARS viruses carried by some of the civet cats at the market in Shenzhen had subtle differences when compared to human variants. One explanation was that the civets had been infected by some other animal in the wild, or on the farms where they bred. “It is conceivable that civets, raccoon dogs, and ferret badgers were all infected from another, as yet unknown, animal source, which is in fact the true reservoir in nature,” wrote Guan and his colleagues. In other words, civet cats and other animals popular in Chinese markets might be “intermediate hosts that increase the opportunity for transmission of infection to humans.”
Since then, further evidence has emerged to support this hypothesis. In 2005 researchers found that Chinese horseshoe bats harbored SARS viruses that were 88 to 92 percent identical to isolates from humans. However, those viruses were missing a crucial protein that binds to a receptor on the surface of human cells, meaning that the bat viruses could not infect humans directly—they would have to pass through an intermediary animal host first. Then, in 2013, scientists from China, Australia, and the United States announced another discovery: after visiting a cave inhabited by horseshoe bats in Kunming, in southern China, they identified two new strains of coronavirus. Unlike previous strains isolated from bats, these did contain the crucial protein enabling them to infect mammalian cells, including cells lining the human lung. Although this was not definitive evidence that SARS could move directly from bats to humans, it suggested that, as with other bat viruses, such as Nipah and Hendra that also cause disease in humans, they had the potential to do so. “I think people should stop hunting bats and stop eating bats,” commented one of the report’s authors, Peter Daszak, the president of EcoHealth Alliance.
They should probably also stop eating civets. To the credit of the Chinese, following the identification of civets infected with SARS, the animals were banned from wet markets and strict infection controls were introduced on civet farms. However, it seems that nothing could sate the Chinese appetite for the exotic mammals, and soon customer demand had driven up the price for civets to $200, making it likely they would find their way onto restaurant menus whatever action the authorities took. The reason? Roasted whole, braised or added to soups, civets are considered a delicacy by the Chinese. They are also said to be full of yang, a heat-giving energy source that, according to traditional beliefs, helps people stay warm in cold weather.
IF AIDS HAD GIVEN the world a preview of how the consumption of bushmeat and faster international communications were presenting animal pathogens with new opportunities to infect human populations and spread around the globe, SARS underlined the risks that the demand for exotic sources of protein and faster international air travel presented in the twenty-first century. Dubbed the “millennium’s first jetset disease,” SARS managed to infect thirty countries worldwide by the simple expedient of hitching lifts on airplanes. All it required were unwitting dupes to carry it onto flights bound for Singapore, Hanoi, Toronto, and other international destinations. That it found these human vessels at the Metropole Hotel was bad luck for the owners of Metropole, but it could just as easily have been any Hong Kong hotel catering to international business travelers and package tourists. Once it was airborne, the virus ensnared the globe in a web of interconnecting lines, like a Lufthansa map iterated to the power of ten. This was something new and scary, serving as a reminder that unlike the physical borders between countries, international airspace is highly porous and vulnerable to interflows of people and pathogens. Coming in the wake of 9/11 and the anthrax letter mailings, it was also a reminder that, in the words of Peiris and Guan, “ ‘nature’ remains the greatest bioterrorist threat of all.”
There were other lessons, too. Perhaps the biggest was that for all that the internet and new web-crawling technologies had given the WHO the ability to monitor disease outbreaks occurring far from the eyes of prying international health officials, governments still had considerable powers to cover up outbreaks and spread disinformation within their own borders, especially where it was felt that transparency might be detrimental to their economic and political interests. Indeed, it was not until mid-April, when a Chinese whistleblower revealed the true numbers of SARS infections in Beijing, that the communist authorities owned up to the full extent of the outbreak and mobilized resources on a scale necessary to quell it. Previously, the Communist Party had insisted there were just thirty-seven cases in the Chinese capital. In fact, by April 19, Beijing had already seen 339 cases, including eighteen deaths, and SARS had also spread to Shanxi province, inner Mongolia, Guangxi, and Fujian. Thanks to the institution of mass quarantines and the construction of new treatment facilities—a feat the Chinese accomplished virtually overnight—disaster was averted, but it was a close call. In all, China reported 5,327 SARS cases, more than any other country. Luckily, the vast majority were confined to Beijing and Guangzhou. However, had the virus become seeded in poorer, rural areas lacking sophisticated medical facilities, it could have been a different story.
Chinese secrecy during the first three months of the outbreak, when SARS was spreading in Guangdong, had sown considerable confusion. Fed misleading information and with incomplete knowledge, WHO officials assumed the outbreak was due to bird flu. On the other hand, once the WHO triggered an international alert and named SARS as the culprit, screening measures at airports were sufficient to prevent further importations of the disease. And for the most part SARS was also controlled in hospitals once the risk of super spre
aders was recognized and managers instituted rigorous infection controls. The result was that although there were 8,422 cases of SARS and 916 deaths globally, the disease was contained without the need for vaccines or specific therapies. Unfortunately, the same thing could not be said for the fear propagated by the WHO alerts. In an era of global news and the internet, news of SARS spread far faster than the virus, amplifying anxiety about the outbreak. As airports shut and pictures of nervous Hong Kong commuters flashed around the globe, the tourism, aviation, and service sectors took a massive financial hit, resulting in an estimated $50 billion in losses to the global economy.
On the other hand, the WHO could take encouragement from the way that GOARN had operated. SARS had been the first opportunity to test whether scientists and clinicians could set aside academic rivalries and work together for the public good by sharing information about the virus and the most effective treatment strategies. Within a month of establishing an international laboratory network, scientists had identified a coronavirus as the cause of SARS. Not long after, they completed the sequencing of its DNA and were on the trail of its animal reservoir. SARS, concluded Heymann, was “proof of the effectiveness of GOARN.” At the same time, he recognized the WHO was also “aided by good fortune” in that the outbreak had occurred in Hong Kong. “Had SARS established a foothold in countries where health systems are less well developed cases might still be occurring,” he observed, “with global containment much more difficult, if not impossible.”
AT A POSTMORTEM at the Royal Society in London, Roy Anderson, the rector of Imperial College and an internationally renowned epidemiologist, was similarly cautious. Although the WHO’s handling of SARS had restored faith in the UN organization, the world had also been “very lucky,” he wrote. It was only thanks to the low transmissibility of SARS and the fact that China and other Asian countries had been able to introduce “fairly draconian” public health measures, such as home isolations and mass quarantines, that disaster had been averted. He predicted such measures would have met greater resistance in North America, where people tended to be more litigious, and to a lesser extent in western Europe. The persistence of SARS in animal reservoirs meant that further outbreaks were inevitable. In the meantime, the real global threat came from the emergence of an antigenically novel influenza virus. “One of the major dangers arising from the effective control of SARS is complacency,” Anderson concluded. “Sentiments of the type, ‘we have been successful once—we will be again,’ may be far from the truth.”
* One of the first samples Peiris tested came from Amoy Gardens; it was positive for antibodies to the coronavirus, confirming that the outbreak in the apartment complex was due to SARS.
CHAPTER VIII
EBOLA AT THE BORDERS
“The outbreak . . . delivered some horrific shocks and
surprises. The world, including WHO, was too slow to see
what was unfolding before us.”
—DR. MARGARET CHAN, Special Session of the
Executive Board on Ebola, Geneva, January 25, 2015
In December 2013 a group of children gathered around the stump of a hollowed-out tree in Meliandou, a remote farming village in southeastern Guinea, and began probing the hollow with a stick. The tree was a well-known roosting spot for lolibelo—a species of insectivorous, long-tailed bats—and the children liked nothing better than coaxing the tiny gray mammals from their hiding places. This was not merely idle sport. In a region where chimpanzees and other sources of bushmeat are scarce, the Angolan free-tailed bat Mops condylurus was an important source of protein. Indeed, for the children of Meliandou the tree stump en route to the village watering hole was the nearest thing to a hamburger stand and Mops condylurus was the equivalent of a Big Mac.
It is not known how many bats the children caught and cooked that morning. In recent years, as more and more forested areas around Meliandou were cleared for palm oil cultivation, the lolibelo had taken to nesting under the roofs of the villagers’ simple mud-and-wattle dwellings and had become a familiar sight. What is known is that shortly after visiting the tree stump, one of the children, a two-year-old boy named Emile Ouamouno, developed a high fever, with vomiting and bloody stools. His father gave him soup in the hope of calming his stomach, but nothing would halt the progress of his illness and on December 6 Emile died. Not long after, Emile’s mother, who was seven months’ pregnant, also fell ill, followed by Emile’s three-year-old sister. This time there was even more blood, and on December 13 Emile’s mother died together with her stillborn baby, followed soon after by Emile’s sister.
Like other villages in the forested region of southeastern Guinea, Meliandou is an endemic area for malaria and Lassa Fever, a hemorrhagic infection spread by rats. Emile’s symptoms and those of his mother and sister resembled both diseases, so at this point no one had any reason to suspect a new pathogen, much less that the lolibelo might be responsible. Had Meliandou lain deep within the forest that might have been the end of the matter, but the village is just six miles along a dirt track from Guéckédou, a busy trading town close to the borders of both Sierra Leone and Liberia. From Guéckédou, a poorly paved highway also leads north to Kissidougou, after which it joins the N1, the road to Guinea’s coastal capital, Conakry.
For the main local ethnic groups, the Kissi and the Gola, trade is their lifeblood. Indeed, the ethonym “Gola” is said to derive from the word for a nut, commonly known as kola, with stimulant properties revered throughout West Africa. It is thought that both groups settled the upper Guinea forest in around the fourteenth century, emigrating west from modern-day Côte d’Ivoire. Of the two, the Kissi are the largest, numbering some 220,000. As they are cut off from the Muslim majority in Conakry, census figures are hard to come by, but it is thought that as many as 80,000 live in the forest on the Guinean side of the border, and a further 140,000 in Liberia and Sierra Leone (by contrast, the Gola are concentrated in western Liberia). Linked by blood, traditions, and a common language, the Kissi have little regard for the colonial-era borders that separate the countries, and extended families travel easily from one to another either by motorcycle along unpaved roads, or, just as frequently, by dugout canoes along the Mano River, which forms a natural boundary between Liberia and Sierra Leone. Little wonder then that within weeks of the mysterious illness appearing in Guéckédou, it had spread beyond the town limits, radiating west to Macenta, east to Kissidougo, and south to Foya in Liberia.
The first person to fall ill outside the family was a midwife who had been summoned by Emile’s grandmother to try to save her pregnant daughter and baby. She was admitted to a hospital in Guéckédou on January 25 and died eight days later on February 2. Unfortunately, before being hospitalized she transmitted the disease to a relative, setting off a new chain of infections in the Guinean border town. By now Emile’s grandmother had also died and at her funeral her sister and several mourners were likewise infected, probably because they prepared her body for burial in accordance with traditional funerary practices. This was followed, on February 10, by an outbreak at a hospital in Macenta. The infection, which was introduced by a health worker from Guéckédou, sparked fifteen further deaths, including that of a local doctor, prompting Guinea’s Ministry of Health to issue an alert on March 10.
One of the first to respond was the private medical charity Médecins Sans Frontières (MSF). In 2010, MSF had established a sentinel facility in Guéckédou to monitor the incidence of malaria; it was only natural that they would assume that the deadly mosquito-borne disease was to blame. But when MSF staff interviewed health workers about the outbreak they discovered that while many of the victims had exhibited symptoms typical of malaria, such as severe headaches and muscle and joint pains, they had also reported profuse bleeding, vomiting, and violent diarrhea, symptoms not at all typical of malaria. In addition, many complained of hiccups. The MSF medics initially suspected Lassa, but when they forwarded their report to Dr. Michael Van Herp, a senior viral hemorrhag
ic fever expert at the organization’s Brussels headquarters, it was the hiccups that caught his attention. They reminded him of a patient he had previously seen with the same symptoms. That patient had had Ebola.
EBOLA HEMORRHAGIC FEVER is one of the most virulent diseases known to man. It is also one of the most terrifying. One moment, victims are complaining of fever, headache, and a sore throat; the next, they are doubled up with abdominal pain, vomiting, and diarrhea. As the symptoms worsen, many also develop a dazed, glassy expression and a purple rash, accompanied by hiccups—caused, most likely, by irritation to the nerves that control the diaphragm. The most alarming symptoms occur several days into the illness when cells infected by the Ebola virus attach themselves to the insides of blood vessels, causing bloody fluids to leak from the mouth, nose, anus, and vagina—even, on occasion, from the eyes. Ebola is especially damaging to the liver, where the virus wipes out cells required to produce coagulation proteins and other important components of plasma. Eventually, this damage reaches a point of no return and patients suffer a fatal drop in blood pressure, terminating in shock and multiple organ failure. Little wonder, then, that one writer has described Ebola as “a perfect parasite . . . [that] transforms virtually every part of the body into a digested slime of virus particles.”