At the novel’s conclusion, as crowds celebrate the infestation’s end, Camus’ protagonist, Dr. Bernard Rieux, “remembered that such joy is always imperiled. He knew what those jubilant crowds did not know . . . that the plague bacillus never dies or disappears for good; that it can lie dormant for years and years in furniture and linen chests; that it bides its time in bedrooms, cellars, trunks, and bookshelves; and that perhaps the day would come when, for the bane and the enlightening of men, it would rouse up its rats again and send them forth to die in a happy city.”
For Camus, “enlightening” was a double-edged word. Nature, red in tooth and claw, can be brutally didactic, as it was with the 1755 Lisbon earthquake. This was a chastening reminder, during the Enlightenment’s high tide of confident aspiration, that nature always has something to say about what human beings always prematurely call “the conquest of nature.”
Humanity, which is given to optimism and amnesia (the latter contributing to the former), was nudged toward theological skepticism by the felt contradiction between the fact of Lisbon and the theory that a benevolent God has ordained Earth as a commodious habitat in a congenial universe. But, then, four centuries before Lisbon, the Black Death plague had killed about one-third of Europe’s population. Besides, the idea that Earth is miraculously biophilic — designed to enable human life to thrive — disregards many inconveniences, from saber-toothed tigers, meteor strikes and typhoons, to volcanoes, insect infestations and multitudes of mutating viruses.
In 1900, about when medicine at last began to do more good than harm, 37 percent of all American deaths were from infectious diseases. Today, the figure is 2 percent. By 1940 and the arrival of penicillin, medicine seemed on the verge of conquering infectious diseases, especially smallpox. No human achievement has done as much to lessen human suffering.
In the early 1950s, the Salk vaccine seemed to complete the conquest by banishing childhood polio, which fostered the misconception that pharmacological silver bullets are the key to large improvements in public health. This distracted attention from the staggering costs of lung cancer, coronary artery disease, AIDS, violence, substance abuses, Type 2 diabetes brought on by obesity and other consequences of known-to-be-risky behaviors.
In last year’s “The Body: A Guide for Occupants,” Bill Bryson notes a milestone in human history: 2011 was the first year in which more people died from noncommunicable diseases (e.g., heart failure, stroke, diabetes) than from all infectious diseases combined. “We live,” Bryson writes, “in an age in which we are killed, more often than not, by lifestyle.” The bacterium that caused the 14th century’s Black Death was in the air, food and water, so breathing, eating and drinking were risky behaviors. Today, deaths from the coronavirus are not apt to match what Bryson calls “suicide by lifestyle,” an epidemic that will continue long after the coronavirus has.
Three decades after Jonas Salk’s good deed, AIDS shattered complacency about infectious disease epidemics being mere memories. AIDS, however, was largely a behaviorally caused epidemic based in the United States primarily in 30 or so urban neighborhoods. Changes in sexual behavior, and less sharing of needles by intravenous drug users, tamed the epidemic.
Modern medicine, and especially pharmacology, has brought Americans blessings beyond their grandparents’ dreams. Nevertheless, a sour aroma of disappointment surrounds health care, which is the most important policy issue in a nation gripped by political, social and actual hypochondria. An old axiom (“Eat sensibly, exercise diligently, die anyway”) has become a new grievance: Medicine’s limitations, made more conspicuous by medicine’s successes, are disturbing reminders of the skull beneath the skin of life.
Because epidemics are silent and invisible during their incubation, and are swift and unpredictable in their trajectories, they could be devastating terror weapons — except that, as the coronavirus is vividly demonstrating, no intentional perpetrator could be confident of remaining immune. The connectedness of the modern world, thanks in part to the jet engine’s democratization of intercontinental air travel, deters the weaponization of epidemics that the connectedness facilitates. For now, this must suffice as good news.