by The Pandemic Century- One Hundred Years of Panic, Hysteria
But this is only one theory. Others put more emphasis on the rapid growth of African cities; the increased prevalence of STDs, including genital ulcers, which would have increased the transmissibility of HIV; and ecological and environmental factors such as the construction of roads through the Congo basin by corporations eager to harvest timber from equatorial Africa. Such roads would have afforded the virus several opportunities to establish itself in human populations: first, by enabling hunters to venture deeper into the habitat of Pt. troglodytes in search of bushmeat; and second, by encouraging the growth of prostitution near camps supplying labor to the timber companies. In this respect, it is argued, HIV may be similar to other viruses, such as Ebola, that are thought to reside in discrete ecological niches and whose emergence can be traced to ecological degradation and environmental changes that bring humans into closer contact with wild animals. However, there is no doubt that phylogenetic analysis of HIV has revolutionized the understanding of AIDS’s global spread, and this is nowhere more true than in the case of one isolate from Africa, known as subtype B.
The story begins in 2008 when Worobey studied six blood samples from Haitian AIDS sufferers who had been treated in Miami in the early 1980s. The isolates exhibited greater genetic diversity than subtype B isolates from any other part of the world except for Africa. This was proof that the subtype had jumped from Africa to Haiti before it had reached the United States. Using the same molecular clock technique he had used to date the common ancestor of the isolates from Léopoldville, Worobey calculated that the founder virus had reached Haiti in around 1966 and had spread to the United States around 1969. A possible source were Haitians who had traveled to Zaire in the early 1960s to work as teachers, doctors, and nurses for WHO and UNESCO programs, one of whom, on their return to Haiti, could have introduced the virus. Pepin further believes that the subtype may have been amplified by unsterile conditions at a private blood-collecting company, Hemo-Caribbean, run by a close ally of the then–Haitian president, François Duvalier. Pepin believes that after the virus spread to Haiti’s heterosexual population, bisexuals communicated it to American sex tourists, including homosexuals from New York and San Francisco who holidayed on the island. Alternatively, since Hemo-Caribbean exported 1,600 gallons of plasma to the United States monthly, and plasma clotting factors were widely used by American hemophiliacs, many of whom died of AIDS, the B subtype could also have been introduced to homosexuals in New York and San Francisco via a hemophiliac.
What is not in dispute is that homosexuals in New York were already infected with the subtype B strain in 1976 and that the same strain was isolated from Gaetan Dugas in 1983. In other words, not only could Dugas not have been patient zero but it is highly unlikely that homosexuals from New York or San Francisco introduced HIV to Haiti either. More likely, it was the other way around. Once gay men from New York and San Francisco were infected with the B strain of HIV from Africa via Haiti, however, the high numbers of sexual partners within this community, coupled with practices such as anal sex, triggered an exponential amplification of the virus, eventually bringing AIDS to the attention of Gottlieb and other American doctors in 1981.
EVEN MORE SO than Legionnaires’ disease, the AIDS pandemic forced scientists to confront the hubristic assumption that medicine was on the verge of conquering infectious disease. This was not only because AIDS patients presented with conditions—PCP, KS, thrush—that were thought to have been consigned to the medical curiosity chest, but because by the time experts woke up to the new syndrome, HIV was widely dispersed and spreading on several continents. As we have seen, this was not the fault of epidemiologists or cancer specialists. On the contrary, AIDS became a pandemic at precisely the moment when, for the first time in history, scientists had the technology and intellectual tools to identify a new retrovirus and devise tests and treatments for it. However, AIDS also underlined something that had been overlooked by scientists and public health officials in the wake of the celebrations that followed the eradication of smallpox in 1980. The first was that pathogens are constantly mutating in ways that are difficult to predict. The second is that humans, either through their changing social and cultural behaviors, or through their impact on the environment and animal and insect ecologies, exert powerful evolutionary pressures on microparasites. Sometimes, these pressures select for a particularly virulent strain of the parasite. At other times, they present the parasite with an opportunity to colonize a new host and extend its ecologic range. This is a particular risk in the case of zoonotic diseases bridged by rodent and insect vectors, such as plague, yellow fever, and dengue. However, it was realized that in an era of increasing globalization, it was also true of other zoonoses that were not nearly as mobile. In particular, it was argued, AIDS would not have been able to escape Africa had humans not changed the rules of “viral traffic.” According to the virologist Stephen Morse, who coined the phrase, these rules included not only environmental and social changes that afforded the simian progenitor of HIV new opportunities for interspecies transfer and amplification within human populations, but such factors as better road and rail connections and international jet travel. Morse’s concerns were soon echoed by other scientists, including the bacterial geneticist and head of Rockefeller University, Joshua Lederberg. In 1989 Lederberg and Morse organized a conference in Washington, DC, then followed it up in 1991 with a scientific report looking at the threat posed by “EIDs.” As defined by the Institute of Medicine report, EIDs included diseases such as AIDS and Ebola that were previously unknown as afflictions of human populations and whose “emergence may be due to the introduction of a new agent, to the recognition of an existing disease that has gone undetected, or to a change in the environment that provides an epidemiologic ‘bridge.’ ” Taking up a theme explored by René Dubos, Lederberg went on to argue that in an era of increasing “globalization,” air travel and the rapid mass movements of goods and people from one part of the globe to another had tilted the balance in favor of microbes, “defining us as a very different species from what we were 100 years ago.” The result, according to Lederberg, was that despite new medical technologies and the wider availability of vaccines and antibiotics, the human race was “intrinsically more vulnerable than before.”
Lederberg’s warning was not lost on the journalist and Science writer Laurie Garrett, who had witnessed the ravages of AIDS in Zaire firsthand. In her 1994 bestseller, The Coming Plague, Garrett explained that thanks to globalization “few habitats on the globe remain truly isolated or untouched,” and because of rapid international jet travel, “a person harboring a life-threatening microbe can easily board a jet plane and be on another continent when the symptoms of illness strike.” AIDS, she concluded bleakly, “does not stand alone,” but was a harbinger of epidemics and pandemics to come.
* Oncovirus is the term for any virus that causes cancers or tumors.
† It subsequently emerged that HTLV-III was identical to LAV and was almost certainly a contaminant from a virus that Montagnier had shared with Gallo’s lab.
‡ The patient was identified in Montangier’s laboratory notes by the first three letters of his name, BRU. He was later named by newspapers as Frédéric Brugière, a homosexual who had allegedly had relations with fifty partners a year and who had visited New York City in 1979.
§ Patient zero is a trope that crops up time and again in narrative accounts of epidemics. In epidemiological terms, patient zero is simply the index case; but in nonfiction and novelistic accounts, patient zero is the embodiment of the pathogen and the personification of the infection about to burst forth in society.
CHAPTER VII
SARS: “SUPER SPREADER”
“The island of Hong Kong is not only the most unhealthy spot in China . . . but the site selected for Victoria, the principal town and seat of government, is the most unhealthy locality of the whole Island, situated as it is on the side of an arid rock, which reflects the rays of a tropical burning sun in a fearfu
l manner.”
—SIR HENRY CHARLES SIRR, China and the Chinese, 1849
It is hard to imagine a less promising site for a major international metropolis than Hong Kong, much less one boasting seven million souls. Perched on the southern edge of the Chinese mainland sixty miles east of Macau, the Special Administrative Area, as Hong Kong has been known since 1997 when the British crown colony reverted to Chinese control, occupies an area of four hundred square miles. But as most of that comprises scattered islands and rugged hills rising steeply from a narrow shoreline, in practice most of the population is crammed into a strip of land on the northern side of Hong Kong island overlooking Victoria Bay, plus the peninsula of Kowloon and the adjoining New Territories. The result is one of the most densely populated cities on Earth and an urban wonder.
Whether arriving by cruise ship or swooping through the clouds in a Boeing 747, one’s first sight of Hong Kong takes the breath away. It is not just that Hong Kong boasts more high rises than any other city on Earth, or that its iconic skyscrapers, such as I. M. Pei’s Bank of China building, once the tallest office building in Asia, seem to defy gravity; it’s the juxtaposition of all that sharp-edged glass and steel with the soft verdancy of those vertiginous hillsides. No matter the depths of a bank’s pockets or the ingenuity of its architects, no human construction can equal the majesty of Victoria Peak, let alone the view from Tai Mo Shan, which at nearly 3,300 feet above sea level marks the highest point on the island. Looking up from the trading floor first thing in the morning, or sipping a cocktail in a luxury penthouse late at night, even a star bond trader cannot help but feel a sense of wonder and reflect on the limits that nature sets on man’s ambitions.
It is not only Hong Kong’s forbidding landscape that has made human settlement a challenge. The island’s unusual topography and subtropical climate are also an ideal breeding ground for malaria and other mosquito-borne diseases, especially during the summer monsoons or the typhoons that batter Hong Kong in the fall. Indeed, such was the island’s reputation for insalubrity that the early British colonists preferred to sleep on board their ships in Victoria harbor rather than risk a bout of “Hong Kong fever” on land. In an era when such fevers were thought to be due to noxious gases emanating from the earth and rocks, such measures made sense. “The geological formation of Hong Kong,” wrote Sir Henry Pottinger, the second colonial governor, in 1843, “is found to consist of strata which quickly absorb any quantity of rain, which it returns to the surface in the nature of a pestiferous mineral gas. The position of the town prevents the dissipation of this gas, while the geological formation favours the retention of the morbific poison on the surface.” Other authorities agreed, arguing that “in the intervals of rain, a nearly vertical sun acts with an intense evaporating power and a noxious steam or vapor rises from the foetid soil, yielding a gas of a most sickly and deleterious nature.” This gas, the writer continued, “produces a depressing effect on mind and body which undermines and destroys the strongest constitutions.”
One of the most feared areas was the harbor and the predominantly Chinese Tai Ping Shan district, a warren of poorly constructed wooden shacks running with raw sewerage in which people, pigs, and rats mingled freely. Even before bubonic plague forced the authorities to level Tai Ping Shan in 1894, the area had a reputation for disease: cholera, typhoid, and smallpox were rife. To escape the successive waves of infection, Hong Kong’s wealthier residents built their homes as far from the waterfront as possible, inching up the slopes of Mount Victoria to about the midpoint of the mountain. One of the first residents of the Mid-Levels, as the area became known, was George Bonham, the governor of Hong Kong from 1848 to 1854. His gated mansion set a precedent, and soon others with names like “Rose Hill,” “Cringleford,” and “Idlewild” followed (one resident was Sara Roosevelt, the mother of Franklin D. Roosevelt, who took up residence here with her family during the American Civil War).
Of course, not everyone could afford such views or such commodious quarters. Instead, as workers from the Chinese mainland poured into Hong Kong in the early 1980s, drawn by its booming economy and liberal political climate, so architects devised ever more ingenious solutions to accommodate the city’s growing population. These public housing projects frequently took the form of multiple occupancy tower blocks rising to forty stories or more. With upwards of twenty apartments per floor, and as many as ten blocks occupying sites of five acres or less, these complexes were practically cities in themselves. Typically, whole families were crammed into single occupancy apartments, reducing the average adult living area in Hong Kong to under two square meters.
With no air conditioning, the apartments were stiflingly hot in summer, the only solution being to throw open a window and risk a lungful of smog from the traffic-clogged streets below, or to install high-powered fans adjacent to the light wells that ran through the center of the blocks. Most families who could afford it opted for the latter, but there was little that could be done about the creaking plumbing and, with so many people showering and flushing at the same time, backups and breakdowns were frequent.
Little wonder, then, that on weekends many sought the fresh air and open spaces of Shek O Country Park or the paved paths and trails that encircle Victoria Peak. But even here, above the mosquito line, comfort was not guaranteed and the island could still spring a surprise. Indeed, longtime residents know that for all that Hong Kong boasts its own subway system, at heart it is still a jungle. Those inviting hillsides, for instance, teem with wild boar and venomous snakes, and hikers are advised to keep a wary eye on the undergrowth for hungry pythons.
It is not pythons that pose the principal threat to Hong Kong’s residents, however. Nor is it mosquitoes: malaria and dengue are no longer endemic to Hong Kong, though on occasion doctors see imported cases. The principal ecological danger comes from Hong Kong’s giant neighbor to the north and the modernizing and urbanizing processes that have intensified the microbial traffic between animals and humans. From Kowloon, on the opposite side of Victoria Bay, it is just ninety minutes by train to Shenzhen and the gateway to Guangdong, the most populous province in China, which is home to some 80 million people. Since the market liberalization measures introduced by China’s Maoist leadership in the late 1970s, Shenzhen and the provincial capital, Guangzhou, have witnessed astonishing rates of economic growth. Spurred by the production of sports trainers, cheap toys, and electronics, between 1978 and 2002 Guangdong’s GDP grew by an average of 13.4 percent per annum, while the urban population of the Pearl River Delta region, which encompasses Guangzhou, expanded to the point where it now accounts for 70 percent of the province’s total population. This manufacturing boom has had two major ecological effects. First, to feed the vast labor force in its factories, Guangdong raises millions of chickens on industrial-scale poultry farms (in 1997, the province was home to an estimated 700 million chickens and by 2008 was producing one billion “high quality” broiler chickens a year). At the same time, rice farmers and smaller livestock producers fatten domestic chickens and ducks in their backyards, hawking the birds in “wet markets” on the edge of urban areas when they are plump and ready for the pot. The result, according to the sociologist and urban historian Mike Davis, is a “fractal pattern of garden plots next to dormitories and factories [that] has brought urban populations and livestock together in more intimate contact.” As many smallholders also keep pigs close to chicken pens, these farming patterns also increase the chances that bacteria and viruses harbored by chickens will inadvertently be communicated to the swine in fecal deposits and that, in turn, pigs will communicate the pathogens to humans. In short, Guangdong has become the potential source of a viral Armageddon and what Davis calls the ecological “monster at our door.”