The Coming Plague: Newly Emerging Diseases in a World Out of Balance

This chapter begins with another look at the AIDS epidemic as it progressed in the 1980s and early 1990s. One of the worrying trends was not a medical concern but a social one: Some countries were trying to limit their exposure to the spread of AIDS by placing restrictions on human rights, passing legislation that targeted minority communities that were thought to be likely carriers. Such reactions were common in some areas of Asia, where autocratic governments were hoping to keep out their first wave of AIDS, but also in the US, where it became a major issue in the 1988 presidential election. “[HIV] was associated with homosexuality, promiscuity, and drug abuse. It pitted public health against organized religion and the moral pillars of society. It was, in short, easy to ignore and uncomfortable to confront” (464).

Garrett identifies three “social epidemics” that accompanied the spread of HIV/AIDS: first, an instinct toward denying the problem existed; second, widespread fear that led to overreactions and victim-blaming; and third, government responses in the form of repression and restriction. Scientists began to see the social context of the disease’s spread as integral to its transmission. In many countries, the marginalization, poverty, and discrimination that accompanied the disease opened further avenues of transmission, as victims were relegated to social contexts with poor care and high rates of contact with other people deemed socially undesirable. The AIDS epidemic, some scientists felt, had to be addressed as a human rights issue.

Another disturbing feature of the spread of AIDS, particularly in Africa, was its potential to cause serious social and economic damage. Its effects threatened to unravel decades of global investment in infrastructure and social capital simply because of the sheer number of people it would kill. As one Kenyan doctor put it, “This is threatening to clear the world” (493). The spread of AIDS went hand-in-hand with social upheavals caused by war in Africa and Southeast Asia, as infections followed displaced people groups and assaults on vulnerable populations. However, these downward social spirals in so-called “third world” countries were not limited to developing nations. Garrett points out that by the fall of communism, much of the Soviet Union’s sphere of influence had also undergone a radical “thirdworldization” in its economic and social conditions, thus amplifying the spread of dangerous diseases. The same was true for industrially developed countries like the US, where some urban neighborhoods had life expectancies lower than the average in any developing nation and where resurgences of old afflictions like tuberculosis were popping back up now in drug-resistant strains.

In 1993, a worrying cluster of cases popped up in the Four Corners region of the US (where New Mexico, Colorado, Utah, and Arizona meet), in which apparently healthy people suddenly went into acute respiratory distress and died. The task of the scientists researching the disease was made more difficult when news of the affliction leaked out in the media as a “Navajo disease,” and racially charged feelings changed the dynamics of the local situation. Work continued, however, and eventually, a sample from the victims tested positive against antibodies for a rodent-borne hantavirus. Hantaviruses had been previously overlooked because they were only known to cause kidney issues, not respiratory symptoms, and were primarily associated with Korea.

This suggested two troubling conclusions: that endemic diseases in one area could potentially reach untouched areas on the other side of the world practically unnoticed and that diseases could adapt to affect whole new systems of the human body. With the global reach of trade, rats from Korea might have made it across the shipping lanes to North America, and there began exchanging viruses with the native rodent population. Somewhere along the line, this transmitted hantavirus gained the ability to strike human lungs with lethal force.

It was also possible that these viruses had long been circulating among North American rodent populations but that no one had ever noticed. If doctors around the Four Corners had not been as swift in recognizing the similarities in their cases, all of them would likely have been written off as deaths from an unknown cause. This suggested that hantaviruses might have been responsible for many similar deaths in the previous decades, but no one had ever identified them as such. For a generation of doctors still struggling with how to address the AIDS epidemic, this situation underscored the need for accurate reporting and organized, cooperative research, both of which had been sorely lacking in most of the outbreak responses of the mid-to-late 20th century:

All ‘new’ diseases must first be noticed by someone who has the insight and courage to sound an alarm and set in motion a thorough investigation. And once in place, investigations are best conducted in an atmosphere of candor and collectivity […] (548).

By the early 1990s, scientists realized that the challenges in dealing with microbes required both a medical understanding of their spread and an ecological understanding. Most of the cases of severe disease outbreaks in the previous decades had been made possible or amplified by human disruptions to microbial ecology, either by changing the broader habitat around the microbes or by exerting selection pressures directly on them (as in the case of applying antibiotics and antivirals).

Microbes, as part of the wider ecosystem, are held in balance by an enormous confluence of factors and changing any of them (as humans are wont to do) can result in opportunities for microbes to exploit the new imbalances. Garrett uses the “Rivet Hypothesis” (put forward by Paul and Anne Ehrlich) to illustrate the point: Human incursions upon the ecological balance are like removing one rivet at a time from a plane while in flight. A rivet here or there might not make much of a difference, but eventually, the changes accrue to the point where removing one more rivet will bring the whole plane down: “The lesson of macroecology was that no species, stream, air space, or bit of soil was insignificant; all life forms and chemical systems on earth were intertwined in complex, often invisible ways” (557). Human alterations to environments had already led to significant ecological catastrophes, including massive die-offs in seal populations, toxic algae blooms, and the gradual loss of the atmosphere’s ozone layer. Continued human incursions into the planet’s most biodiverse regions, the rainforests, raised the constant possibility of zoonotic spillover events, in which unknown microbes were passed from their animal reservoir species into humans—“the worst scales of disease and death arose from [such] events” (572).

The human body itself provides a new macro-level ecology for microbes, in which they have a near-infinite number of opportunities to multiply, recombine, mutate, and spread. Garrett cites evidence that points to microbes being able to adapt faster than purely random chance would permit, suggesting that their active use of defense strategies allows them, at least in some sense, to choose the direction of their transformations. This opens the door for microbial invaders to adapt themselves toward greater virulence should the opportunity arise, without having to wait for random mutations.

As the global medical community entered the 1990s, it was struck by a sense that its professional structures were insufficient to deal with the threat of emerging diseases. New doctors were being trained in highly specialized fields, with very few opting for fieldwork in areas of the world where microbial overspill was most likely. The training and experience that had shaped the generation of “disease cowboys” was now almost nonexistent in the medical community. Further, the increasingly intimate ties of global trade and travel were offering ever-greater opportunities for overspill events to spread rapidly around the world, as illustrated in the case of a monkey-specific Ebola strain that managed to reach New York City in 1989 before anyone had even become aware of it.

The scientific community also needed an organized method of reporting new outbreaks and providing a centralized, coordinated response. No one, however, had much of an answer for which agency should provide that response. Few had faith in the World Health Organization’s resources, and while the US’s CDC was an obvious choice, many areas of the world leaned on other agencies in Paris, London, and elsewhere, meaning there was no central coordination for assessing or dealing with outbreak reports. Even if a centralized response could be managed, generating outbreak reports in the field was no sure thing, as there was no established reporting network worldwide, and those existing stations were understaffed and undersupplied.

Even should coordinated responses and government support somehow materialize, the world still faces the difficulty of limiting the risks of several major amplifiers of disease emergence. Garrett enumerates these amplifiers as multiple-partner sex, the reuse of syringes in medical and illegal-drug contexts, medical environments promoting drug resistance, and air recirculation systems, all of which played pivotal roles in 20th-century epidemics. Finding practical ways of addressing these issues would be a necessary first step, but ultimately, achieving a stable balance against the incursions of microbes would require humanity to change its behavior toward the wider environment: “Only by appreciating the fine nuances in their ecologies can human beings hope to understand how their actions, on the macro level, affect their micro competitors and predators. Time is short” (619).