How Epidemics Change Civilizations

Measures developed for the plagues of the 14th century are helping authorities fight the coronavirus now, says Yale historian Frank Snowden.


Jason Willick

March 27, 2020 7:06 pm ET

To put the coronavirus pandemic in perspective, consider what happened when the bubonic plague struck London in 1665. The onset of the disease could be sudden, says Yale historian Frank Snowden: “You actually have people afflicted and in agony in public spaces.” Trade and commerce swiftly shut down, and “every economic activity disappeared.” The city erected hospitals to isolate the sick. “You have the burning of sulfur in the streets—bonfires to purify the air.”

Some 100,000 Londoners—close to a quarter of the population, equivalent to two million today—died. Some sufferers committed suicide by “throwing themselves into the Thames,” Mr. Snowden says. “Such was their horror at what was happening to their bodies, and the excruciating pain of the buboes”—inflamed lymph nodes—that are the classic symptom of the bubonic plague. Social order broke down as the authorities fled. “Death cart” drivers went door to door, collecting corpses for a fee and sometimes plundering the possessions of survivors.

The plague’s violent assaults on European cities in the Middle Ages and Renaissance periods created “social dislocation in a way we can’t imagine,” says Mr. Snowden, whose October 2019 book, “Epidemics in Society: From the Black Death to the Present”—a survey of infectious diseases and their social impact—is suddenly timely.

I interviewed Mr. Snowden, 73, over Skype. We’re both home in lockdown, I in California and he in Rome, where he’s gone to do research in the Vatican archives. In the mid-14th century, Italy was “the most scourged place in Europe with the Black Death,” he notes. In the 21st century, it’s among the countries hardest hit by Covid-19.

Science has consigned the plague, caused by the flea- and rat-borne bacterium Yersinia pestis, to the margins of public-health concern (though it remains feared as a potential aerosolized bioweapon). Yet its legacy raises challenging questions about how the coronavirus might change the world.

For all the modern West’s biomedical prowess, some of its blunt tools against a poorly understood disease are similar to what was first attempted in the 14th century. Take quarantine. Hundreds of millions of Americans and Europeans are isolated in their homes in an effort to slow the spread of the coronavirus.

Isolation as a defense against infectious disease originated in the city-states of Venice and Florence. Italy was the center of Mediterranean trade, and the plague arrived in 1347 on commercial ships. The dominant theory at the time was “miasmatism”—the atmosphere was poisoned—perhaps by visitors’ garments—and people get sick “when they breathe that in, or absorb it through their pores,” Mr. Snowden says. “That is, there is some emanation, and it can be thought to be coming from the soil, or from the bodies” of sick people.

After plague visitations, the Venetian navy eventually began to force sailors arriving at the harbor to disembark on a nearby island, where they remained for 40 days—quaranta—a duration chosen for its biblical significance. The strategy worked when it was enforced as disease-ridden fleas died out and the sick died or recovered. Mr. Snowden notes that Americans returning from Wuhan, China, in early February were “detained on army bases for a quarantine period”—14 days rather than 40.

“We can see the roots of many aspects of modern health already in the Renaissance,” he adds. Another example is the wax “plague costume” worn by physicians. It resembled modern-day medical garb—“the protective garments that you see in the hospital for people dealing with Ebola, or this sort of space suit”—but with a long beak containing resonant herbs. They were thought to “purify the air that you were breathing in.” The costume “did, in fact, have some protective value,” Mr. Snowden says, because the wax repelled the fleas that carried the disease.

Antiplague efforts dramatically changed Europeans’ relationship to government. “The Florentines established what were called health magistrates, which are the ancestors of what today we call boards of health or departments of health,” Mr. Snowden explains. “Endowed with special legal powers,” they coordinated plague countermeasures.

The plague was more traumatic than a military assault, and the response was often warlike in its ferocity. One response was a “sanitary cordon,” or encircling of a city-state with soldiers, who didn’t allow anyone in or out. “Imagine one’s own city, and suddenly, in the morning, it’s cordoned off by the National Guard with fixed bayonets and helmets on, and orders to shoot if we cross,” Mr. Snowden says. Cordons were regularly imposed in European cities in times of plague risk, leading to terror and violence. In the 18th century, the Austrian army was “deployed to prevent bubonic plague from moving up the Balkan Peninsula and into Western Europe” by halting travelers who might be carrying it.

The sociologist Charles Tilly (1929-2008) famously argued that “war makes the state”—that borders and bureaucracies were forged by necessity in military conflict. Plague had similar effects, requiring “military commitment, administration, finance and all the rest of it,” Mr. Snowden says. In addition to a navy to enforce quarantines, “you needed to have a police power,” a monopoly on force over a wide area. Sometimes “watchmen were stationed outside the homes of people who had the plague, and no one was allowed in or out.”

Yet while the plague saw power move up from villages and city-states to national capitals, the coronavirus is encouraging a devolution of authority from supranational units to the nation-state. This is most obvious in the European Union, where member states are setting their own responses. Open borders within the EU have been closed, and some countries have restricted export of medical supplies. The virus has heightened tensions between the U.S. and China, as Beijing tries to protect its image and Americans worry about access to medical supply chains.

The coronavirus is threatening “the economic and political sinews of globalization, and causing them to unravel to a certain degree,” Mr. Snowden says. He notes that “coronavirus is emphatically a disease of globalization.” The virus is striking hardest in cities that are “densely populated and linked by rapid air travel, by movements of tourists, of refugees, all kinds of businesspeople, all kinds of interlocking networks.”

The social dynamics of a pandemic are determined partly by who is most affected. Cholera, for example, “is famously associated with social and class tensions and turmoil,” Mr. Snowden says. A vicious gastrointestinal infection, it was most prevalent in crowded urban tenements with contaminated food or water. “We could pick Naples, or we could pick New York City in the 19th century,” he says. “Municipal officials, the authorities, the doctors, the priests, the middle classes, the wealthy, who live in different neighborhoods, are not succumbing to this disease.” That led to conspiracy theories about its origin, and to working-class riots.

Similarly, the bubonic plague struck India, then a British colony, in the late 19th century. The British responded by introducing Renaissance-era antiplague measures—“very draconian exercises of power and authority, but by a colonial government, over the native population,” Mr. Snowden says. “The population of India regarded this as more fearful than the plague itself” and resisted. Britain, worried that “this would be the beginning of modern Indian nationalism,” backed off the measures, which were mostly ineffective anyway.

Respiratory viruses, Mr. Snowden says, tend to be socially indiscriminate in whom they infect. Yet because of its origins in the vectors of globalization, the coronavirus appears to have affected the elite in a high-profile way. From Tom Hanks to Boris Johnson, people who travel frequently or are in touch with travelers have been among the first to get infected.

That has shaped the political response in the U.S., as the Democratic Party, centered in globalized cities, demands an intensive response. Liberal professionals may also be more likely to be able to work while isolated at home. Republican voters are less likely to live in dense areas with high numbers of infections and so far appear less receptive to dramatic countermeasures.