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When Epidemics Wreaked Havoc in America

Deadly infectious diseases were once common in the U.S., until science conquered them. In today’s crisis, it’s worth recalling those celebrated victories.

It may have been the high point of America’s fragile love affair with medical science. “SALK’S VACCINE WORKS,” screamed the nation’s headlines on April 12, 1955. “POLIO IS CONQUERED.” An insidious childhood disease that came like clockwork each summer during the middle years of the 20th century, killing thousands and crippling many more, would be all but eradicated in the U.S. within a single generation.

Dr. Jonas Salk, inventor of the polio vaccine, receives a special citation from President Eisenhower at the White House, 1955.

Rarely, if ever, had a scientist received the instant adulation that awaited Jonas Salk. Tributes piled up, including the Congressional Gold Medal, awarded previously to the likes of Thomas Edison, Charles Lindbergh and General George C. Marshall. The Eisenhower White House circulated a memo suggesting a Rose Garden ceremony for maximum political gain: “We’ve [got to] show that the president is just as interested as [Franklin D. Roosevelt] in polio…to take away the perennial Democratic thunder.” Yet those who witnessed the event were touched by its simple humanity. “No bands played and no flags waved,” wrote a reporter who had followed Eisenhower for years. “But nothing could have been more impressive than this grandfather standing there and telling Dr. Salk in a voice trembling with emotion, `I have no words to thank you. I am very, very happy.’”

New vaccines soon followed—for measles, mumps and rubella. Coupled with earlier laboratory miracles, including the introduction of antibiotics like penicillin and streptomycin, Americans saw a huge jump in their life expectancy, driven by the precipitous decline of infectious diseases. The war against germs, it appeared, had become a rout.

The impact of disease on American history is a remarkably understudied subject. Textbooks give it short shrift in comparison to political, military, diplomatic and economic affairs, but the catalog of key episodes is long. We must not forget that the European conquest and settlement of the Americas were largely dependent on the deadly diseases the settlers brought; or that the grand plan of the Continental Congress to conquer Quebec in 1775 was halted, in large part, by a fearful smallpox outbreak among the troops; or that more American soldiers died from influenza during World War I than from battle wounds, in a pandemic that killed upward of 50 million people world-wide.

It takes the fear of a pandemic, as we are experiencing today with Covid-19, to remind us that infectious diseases were once so common, so deadly, that Americans had little choice but to accept the toll they exacted with stoicism and dread. Death by epidemic remained a natural, if depressing, part of American life until just a few generations ago.

Take yellow fever, for example. A virus transmitted by the bite of the female Aedes aegypti mosquito, with a mortality rate sometimes approaching 50%, it came to the Americas on slave ships from Africa. As trade routes expanded, it reached the port cities of North America, striking Philadelphia, the young nation’s capital, in 1793, where it killed at least 10% of the population and caused the federal government to temporarily disband. Most of Congress fled the city, as did President George Washington and Secretary of State Thomas Jefferson, an ardent defender of rural values, who found odd comfort amid the carnage. “The yellow fever will discourage the growth of cities in our nation,” he wrote a friend, “& I view great cities as pestilential to the morals, the health and the liberties of man.”

A woodcut shows a scene from the 1793 yellow fever epidemic in Philadelphia.

Americans were stumped by its spread. The fact that a vector as tiny as a mosquito could cause a catastrophe of this magnitude was simply beyond anyone’s comprehension. Physicians blamed the disease on miasmas—the noxious vapors arising from corpses, rotting food, and swamp and sewer gases—that were believed to form dangerous airborne clouds. The diaries these doctors justify behind show how completely they missed the signals that now seem so obvious today. All complained about mosquitoes swarming and biting, relentless and inescapable. One remarked that he’d never seen as many people “covered with blisters from their venomous operations.” Yet it would be another full century before Dr. Walter Reed confirmed the transmission of the disease by mosquito, which led, in turn, to the draining of swamps, the screening of windows, the development of insecticides and eventually a vaccine.

New York City also saw its share of epidemics. Hardly a decade went by in the 1700s without a serious smallpox eruption. One outbreak in 1731 killed more than 500 of the city’s 10,000 residents, roughly three times the percentage of New Yorkers who would die in the influenza pandemic of 1918.

As the city grew, quickly becoming America’s largest, observers described a pulsing new energy—“a sea of masts” in the harbor, “streets jammed with carts and wheel barrows, buildings “rising everywhere.” But that harbor became something ominous as well: a magnet for the world’s microbes and maladies. Diseases like scarlet fever, measles, typhus and “throat distemper” (diphtheria) came in giant waves. Yet for sheer terror, nothing quite matched cholera, which repeatedly brought New York to a stop.

A bacterial disease, spread through food and water contaminated by the excrement of infected victims, cholera causes the body to expel enormous quantities of liquids through vomiting and explosive diarrhea. There is no incubation period. The victim can be fine in the morning and dead by nightfall.

Having not a clue as to its cause, authorities blamed it on miasmas and slum-dwelling immigrants—in this case, the Irish. “As a class of people,” wrote one New York physician, “they are exceedingly dirty, exhausted by drunkenness, and crowded together in the worst portions of the city.” Certainly his last charge was true. Fleeing the rural starvation of Counties Cork, Kerry and Sligo for the slums of New York City, the Irish lived in ghastly squalor, using whatever water was at hand. In Five Points, their primary neighborhood, that meant a series of shallow wells polluted by fecal waste from backyard privies.

The result was predictable. The foreign-born accounted for 71% of the deaths from the 1832 cholera epidemic, at a time when immigrants were barely 10% of New York City’s population. Sympathy was in short supply. Indeed, the response from many quarters was even harsher than Jefferson’s view of Philadelphia. “Those sickened must be cured or die off,” wrote an unforgiving New York official, “& being chiefly of the very scum of the city, the quicker their dispatch, the sooner the malady will cease.”

How did other New Yorkers approach cholera? In medieval fashion: They quarantined the victims and then humbled themselves before God. Sermons, prayers and fasting were highly recommended; if all else failed, run like hell. One observer compared the exodus of “well-filled stage coaches” during the summer of 1832 to the stampede from Pompeii “when the red lava flowed.” Social distancing favored the rich. Those with means weren’t inclined to stick around.

In 1870, one child in five born in New York City would not live to see his first birthday.

Two decades later, a brilliant British physician named John Snow would introduce the modern field of epidemiology by mapping cholera deaths surrounding a polluted well in central London. He showed that the disease was transmitted not by noxious fumes in the atmosphere but rather by something in the drinking water, which he couldn’t actually see. His so-called Ghost Map convinced local authorities to remove the well’s pump handle—and the epidemic ceased. In 1884, German researcher Robert Koch identified that mysterious agent, Vibrio cholerae, under a microscope, a discovery that helped to demolish the miasma theory for good.

Some deadly diseases came and went; others, such as tuberculosis, typhoid fever and smallpox, lingered for centuries, despite medical breakthroughs that included Edward Jenner’s miraculous smallpox vaccine. In comparison to Europe, where bacterial research had begun in earnest by the mid-19th century, American medicine proved somewhat slow to give up old habits and ideas, from bleeding and purging the patient to the acceptance of germ theory, which stipulated that invisible organisms caused specific diseases and that antiseptic methods might be employed to halt their spread. In 1870, one child in five born in New York City would not live to see his first birthday, and 25% of those who did reach adulthood would die before the age of 30.

Vials of Jonas Salk’s new polio vaccine, April 1955.

The unfettered optimism surrounding the era of Salk and miracle drugs was understandable, if somewhat premature. The U.S. had recently survived a depression and won a two-front global war. The atomic age had dawned. Science and technology were riding high. Nothing now seemed beyond the reach of the laboratory to heal or to prevent. Some spoke openly of a future without infectious disease. “Will such a world exist?” asked one prominent scientist. “We believe so.”

It hasn’t turned out that way. AIDS, SARS, MERS, Zika, Ebola, swine flu, superbugs—all bear witness to the arrogance of that remark. And yet it’s equally true that until a month or two ago, Americans went about their business without the slightest concern that an epidemic on the scale of smallpox or cholera or yellow fever might randomly strike them down.

There’s a reason we’re emotionally unprepared for what may lie ahead: We simply haven’t experienced the extreme cycles of infectious disease that previous generations were forced to endure. We’re in frightening new territory, wondering if there is enough protective equipment for medical personnel and first responders, if there are enough test kits and ventilators for possible victims, if an effective vaccine is really a year or so away.

Many wonder as well about the new dangers unleashed by globalization. Germs travel, and the consequences can be severe. But that’s the way it’s been for centuries, at an admittedly slower pace. Yellow fever and malaria came to North America from Africa; cholera and typhus rode the steamers and “coffin ships” that discharged immigrant cargo at our shores. History assures us that Covid-19 will be conquered by science and that another virus, originating in a bat cave, a pig farm or an open-air poultry market somewhere in the world, will rise up to take its place. That’s the nature of the beast.

In times like this, when anxiety turns so easily to fear, it sometimes helps to focus upon an optimistic vision of the future. For me, it’s the image of a war hero turned president tearfully thanking a selfless researcher for helping to save the children of the world.

Prof. Oshinsky is a member of the history department at New York University and director of the Division of Medical Humanities at NYU Langone Health. His book, “Polio: An American Story” won the 2006 Pulitzer Prize for history.

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