New ideas of living
Throughout millennia, people have fostered some pretty irrational ideas about how infectious diseases such as plague and cholera were spread. Some of those notions—like the idea that the ancient Cyprian plague could be caught simply by staring into the face of someone afflicted—seem laughable, like something the Monty Python troupe might have sprinkled into one of their medieval parody scripts for television.
Yet even as waves of disease washed again and again over population centers, it took centuries for science to fully understand the invisible world of microbes. Until that happened, people under pandemic siege tried to explain the overwhelming amount of death they saw in different ways. Some used simple observations, while some turned to fervent beliefs. Others viewed the cataclysm through the lens of their long-held biases, while still others processed the carnage through superstitions and bizarre theories.
When masses of people started inexplicably dying, many early cultures looked first to a vengeful or unforgiving God—or gods. In ancient Greek mythology, which often served as allegory for actual events, Homer wrote in The Iliad of the god Apollo raining plague down on the Greek army with his arrows during the Trojan War, killing animals first, then soldiers. Apollo’s arrows came to symbolize disease and death.
Throughout the centuries, plague arrived in wave after devastating wave, taking numerous forms—from bubonic (which affects the lymphatic system) to pneumonic (which attacks the lungs) to septicemic (which infiltrates the bloodstream). Perhaps the most virulent occurrence came in the mid 1300s with the Black Death, which felled more than 20 million people across Europe alone. While it’s largely believed that bacteria-carrying fleas were the main culprit, “experts” at the time found other explanations—especially in astrology and broadly formed ideas of “noxious vapors” as a breeding ground for pestilence.
In 1348, for example, King Philip VI of France asked the greatest medical minds at the University of Paris to report back to him on the causes of the bubonic plague. In a detailed document submitted to the crown, they blamed “the configuration of the heavens.” Specifically, they wrote that, in 1345, “at one hour after noon on 20 March, there was a major conjunction of three planets [Saturn, Mars and Jupiter] in Aquarius.” Adding to that, they noted, a lunar eclipse occurred around the same time.
Citing ancient philosophers such as Albertus Magnus and Aristotle, the Parisian medical scholars went on to connect the dots between planets and pestilence: “For Jupiter, being wet and hot, draws up evil vapors from the earth and Mars, because it is immoderately hot and dry, then ignites the vapors, and as a result there were lightning, sparks, noxious vapors and fires throughout the air.”
Terrestrial winds, they went on, spread the noxious airs widely, smiting down “the life force” of anyone who ingested it into their lungs: “This corrupted air, when breathed in, necessarily penetrates to the heart and corrupts the substance of the spirit there and rots the surrounding moisture, and the heat thus caused destroys the life force, and this is the immediate cause of the present epidemic.”
A few centuries later, those noxious vapors were given another label: “miasma.” If it smelled bad, people reasoned, it must carry disease. That explains why, during the plague of 1665, some doctors donned beak-shaped masks filled with sweet-smelling flowers—to protect themselves from infection.
And never mind that playwright and poet William Shakespeare, like other Londoners of the early 1600s, bathed infrequently, and lived among rats, filth, fleas and sewage-filled street gutters. He, too, thought plague was an atmospheric thing. And taking the heavenly explanation even further, he wrote that malaria, a separate epidemic caused by swamp mosquitos along the Thames River, was caused by the sun steaming up swamp “vapors.”
Pandemics have long bred prejudice and mistrust, and fueled longstanding biases, as traumatized communities have looked to blame others as unclean or malicious spreaders of disease.
Throughout medieval Europe the plague became an excuse to scapegoat and massacre Jewish people. Medieval Christian mobs attacked Jewish ghettos with virtually every wave of the disease, claiming that Jewish citizens poisoned wells and conspired with demons to spread the disease. In one pogrom, 2,000 Jews were burned alive in the city of Strasbourg on February 14, 1349.
Meanwhile, in the 19th and early 20th centuries, cholera sweeping across Europe became the subject of wild class-based conspiracy theories, as poor and marginalized people accused the ruling elite of ruthlessly working to cull their ranks by spreading the disease and deliberately poisoning them. From Russia to Italy to the United Kingdom, scores of riots followed, with members of the police, government and medical establishments murdered, and hospitals and town halls destroyed.
In the absence of scientific certainty, pandemics have often inspired people to grasp at answers based on whatever they immediately observe around them. With the Russian flu of 1889, bizarre theories evolved quickly into widely disseminated rumors. One newspaper, The New York Herald, speculated that the flu could travel on telegraph wires, after a large number of telegraph operators seemed to contract the disease. Others hypothesized that the flu may have arrived on letters from Europe, since mail carriers had begun to fall ill. In Detroit, when bank tellers began to get sick, some jumped to the conclusion that they'd caught it from handling paper money. Other rumored culprits included dust, postage stamps and library books.
Eventually, science began to see the unseen, and to explain why people dropped dead by the thousands. Of course, there were some plague-related issues that would always require a higher power. During the Middle Ages, it was believed that sneezing not only spread Black Death but caused a person to expel their soul.
As human civilizations flourished, so did infectious disease. Large numbers of people living in close proximity to each other and to animals, often with poor sanitation and nutrition, provided fertile breeding grounds for disease. And new overseas trading routes spread the novel infections far and wide, creating the first global pandemics.
Three of the deadliest pandemics in recorded history were caused by a single bacterium, Yersinia pestis, a fatal infection otherwise known as the plague.
The Plague of Justinian arrived in Constantinople, the capital of the Byzantine Empire, in 541 CE. It was carried over the Mediterranean Sea from Egypt, a recently conquered land paying tribute to Emperor Justinian in grain. Plague-ridden fleas hitched a ride on the black rats that snacked on the grain.
The plague decimated Constantinople and spread like wildfire across Europe, Asia, North Africa and Arabia killing an estimated 30 to 50 million people, perhaps half of the world’s population.
“People had no real understanding of how to fight it other than trying to avoid sick people,” says Thomas Mockaitis, a history professor at DePaul University. “As to how the plague ended, the best guess is that the majority of people in a pandemic somehow survive, and those who survive have immunity.”
The plague never really went away, and when it returned 800 years later, it killed with reckless abandon. The Black Death, which hit Europe in 1347, claimed an astonishing 200 million lives in just four years.
As for how to stop the disease, people still had no scientific understanding of contagion, says Mockaitis, but they knew that it had something to do with proximity. That’s why forward-thinking officials in Venetian-controlled port city of Ragusa decided to keep newly arrived sailors in isolation until they could prove they weren’t sick.
At first, sailors were held on their ships for 30 days, which became known in Venetian law as a trentino. As time went on, the Venetians increased the forced isolation to 40 days or a quarantino, the origin of the word quarantine and the start of its practice in the Western world.
London never really caught a break after the Black Death. The plague resurfaced roughly every 20 years from 1348 to 1665—40 outbreaks in 300 years. And with each new plague epidemic, 20 percent of the men, women and children living in the British capital were killed.
By the early 1500s, England imposed the first laws to separate and isolate the sick. Homes stricken by plague were marked with a bale of hay strung to a pole outside. If you had infected family members, you had to carry a white pole when you went out in public. Cats and dogs were believed to carry the disease, so there was a wholesale massacre of hundreds of thousands of animals.
The Great Plague of 1665 was the last and one of the worst of the centuries-long outbreaks, killing 100,000 Londoners in just seven months. All public entertainment was banned and victims were forcibly shut into their homes to prevent the spread of the disease. Red crosses were painted on their doors along with a plea for forgiveness: “Lord have mercy upon us.”
As cruel as it was to shut up the sick in their homes and bury the dead in mass graves, it may have been the only way to bring the last great plague outbreak to an end.
Smallpox was endemic to Europe, Asia and Arabia for centuries, a persistent menace that killed three out of ten people it infected and left the rest with pockmarked scars. But the death rate in the Old World paled in comparison to the devastation wrought on native populations in the New World when the smallpox virus arrived in the 15th century with the first European explorers.
The indigenous peoples of modern-day Mexico and the United States had zero natural immunity to smallpox and the virus cut them down by the tens of millions.
“There hasn’t been a kill off in human history to match what happened in the Americas—90 to 95 percent of the indigenous population wiped out over a century,” says Mockaitis. “Mexico goes from 11 million people pre-conquest to one million.”
Centuries later, smallpox became the first virus epidemic to be ended by a vaccine. In the late 18th-century, a British doctor named Edward Jenner discovered that milkmaids infected with a milder virus called cowpox seemed immune to smallpox. Jenner famously inoculated his gardener’s 9-year-old son with cowpox and then exposed him to the smallpox virus with no ill effect.
“[T]he annihilation of the smallpox, the most dreadful scourge of the human species, must be the final result of this practice,” wrote Jenner in 1801.
And he was right. It took nearly two more centuries, but in 1980 the World Health Organization announced that smallpox had been completely eradicated from the face of the Earth.
In the early- to mid-19th century, cholera tore through England, killing tens of thousands. The prevailing scientific theory of the day said that the disease was spread by foul air known as a “miasma.” But a British doctor named John Snow suspected that the mysterious disease, which killed its victims within days of the first symptoms, lurked in London’s drinking water.
Snow acted like a scientific Sherlock Holmes, investigating hospital records and morgue reports to track the precise locations of deadly outbreaks. He created a geographic chart of cholera deaths over a 10-day period and found a cluster of 500 fatal infections surrounding the Broad Street pump, a popular city well for drinking water.
“As soon as I became acquainted with the situation and extent of this irruption (sic) of cholera, I suspected some contamination of the water of the much-frequented street-pump in Broad Street,” wrote Snow.
With dogged effort, Snow convinced local officials to remove the pump handle on the Broad Street drinking well, rendering it unusable, and like magic the infections dried up. Snow’s work didn’t cure cholera overnight, but it eventually led to a global effort to improve urban sanitation and protect drinking water from contamination.
While cholera has largely been eradicated in developed countries, it’s still a persistent killer in third-world countries lacking adequate sewage treatment and access to clean drinking water.
The news was terrifying to colonists in Massachusetts: Smallpox had made it to Boston and was spreading rapidly. The first victims, passengers on a ship from the Caribbean, were shut up in a house identified only by a red flag that read “God have mercy on this house.” Meanwhile, hundreds of residents of the bustling colonial town had started to flee for their lives, terrified of what might happen if they exposed themselves to the frequently deadly disease.
They had reason to fear. The virus was extremely contagious, spreading like wildfire in large epidemics. Smallpox patients experienced fever, fatigue and a crusty rash that could leave disfiguring scars. In up to 30 percent of cases, it killed.
But the smallpox epidemic of 1721 was different than any that came before it. As sickness swept through the city, killing hundreds in a time before modern medical treatment or a robust understanding of infectious disease, an enslaved man known only as Onesimus suggested a potential way to keep people from getting sick. Intrigued by Onesimus’ idea, a brave doctor and an outspoken minister undertook a bold experiment to try to stop smallpox in its tracks.
Smallpox was one of the era’s deadliest afflictions. “Few diseases at this time were as universal or fatal,” notes historian Susan Pryor. The colonists saw its effects not just among their own countrymen, but among the Native Americans to whom they introduced the disease. Smallpox destroyed Native communities that, with no immunity, were unable to fight off the virus.
