Pandemic: Tracking Contagions, from Cholera to Coronaviruses and Beyond

by Sonia Shah

Of 4,600 species of mammals on earth, 20 percent are bats.

For example, because their bones are hollow, like those of birds, they don’t produce immune cells in their bone marrow like the rest of us mammals do.

Perhaps the toddler had played with a piece of fruit covered with bat saliva, fallen from a nearby tree.

Sporadic, contained eruptions in remote villages in Central Africa had occurred since the 1970s, mostly during the transition between rainy and dry seasons, possibly connected to the fruiting of trees, and in the wake of the arrival of large numbers of migratory bats.

That estimate proved to be overblown, but many believed it possible at the time. Ebola had already wreaked catastrophic damage on our fellow primates, the gorillas and chimpanzees who feed on the same fruit trees as fruit bats.

the virus that caused smallpox, which killed between 300 and 500 million people over the course of the twentieth century.

When she tallied her numbers, she found that monkeypox infection in humans had grown twentyfold

It was only then, after the size and scale of wet markets grew, that a serendipitous sequence of events that could turn a virus of horseshoe bats into a human pathogen became probable.

40 percent of those infected. Nipah virus also struck in South Asia and now erupts in Bangladesh nearly every year, killing 70 percent of the afflicted.

But avian biodiversity, like the biodiversity of other species, has plummeted, in the United States as elsewhere. Urban sprawl, industrial agriculture, and climate change, among other disruptions caused by human activity, steadily destroy bird habitats, reducing the number of species among us.

That means there’s more food and territory around for the “generalist” species like robins and crows—the opportunistic, sharp-elbowed types that can live anywhere and eat anything. Their numbers skyrocket in the vacuum.

Within five years, the virus had emerged in all forty-eight contiguous states. By 2010, an estimated 1.8 million people in North America had been infected from New York to Texas and California. Experts agree that West Nile is here to stay.

Just how these losses will shift the distribution of microbes between and across species, pushing some over the threshold, remains to be seen.53 *

My Jain aunt wouldn’t even accept my youthful offer of a goldfish cracker, because of the sinful implication of its fishy shape.

Cholera could never have caused pandemics without the new modes of transport developed in the nineteenth century.

Muscles, deprived of oxygen, shuddered so violently that they sometimes tore.

As the organs collapsed in turn, victims fell into acute shock, all the while fully conscious and expelling massive amounts of liquid stool.

Cholera was humiliating, uncivilized, an affront to nineteenth-century sensibilities. This exotic invader, the historian Richard Evans writes, transformed enlightened Europeans into a race of savages.15

(Poor Winslow himself had been mistakenly declared dead and boxed in a coffin twice as a child.)

In the 1790s, a new system implemented at Paris mortuaries required that corpses be outfitted with special gloves, such that if a corpse’s finger so much as trembled, a string would be pulled and a large hammer would slam down on an alarm. Guards patrolled the mortuary under the direction of local physicians, ears peeled.

(Today, we surveil the living for signs of death; back then, they surveilled the dead for signs of life.)

“It is so easy to be completely mistaken,”

Local authorities outlawed public gatherings and banned markets within the city center. They marked victims’ homes, quarantining survivors inside.

In the evenings during that terrible spring, Paris’s elite attended elaborate masquerade parties where, in denial and defiance of cholera’s toll, they danced to “cholera waltzes,” costumed as the ghoulish corpses many would soon become.

cholera balls,

Cholera killed them so fast they went to their graves still clothed in their costumes.

Edgar Allan Poe—to pen “Masque of the Red Death,”

The Dutch, who settled what would become New York City,

newly established Bank of the Manhattan Company (later to become the multinational behemoth JPMorgan Chase), established something novel in transatlantic shipping:

Before setting sail, ships often filled their drinking-water casks from the same streams and bays in which local people bathed and defecated.

By land, the interior of the United States at the time of cholera’s emergence was largely impenetrable. Most of the nation’s roads were little more than muddy tracks through wild forests and swamps, on which fallen trees and mud could strand horse-drawn carriages and carts for weeks.

Newly developed steamboats allowed passengers to travel up and down natural waterways such as the three-hundred-mile-long Hudson River, which ran from the Adirondack Mountains to New York City, and the two-thousand-mile Mississippi River, which flowed from northern Minnesota to the Gulf of Mexico.

30 Cholera or any other waterborne pathogen that made it to U.S. shores was blocked from the waterways farther west.

The Erie Canal,

It was a marvel of engineering, bought for the then astronomical sum of $7 million (that’s some $130 billion in 2010 dollars),

And along with the wheat and tea came waves of immigrants. They disembarked from schooners that crossed the Atlantic, rode along the canal, and transferred to new vessels for the continuing journey westward on the water, bringing cholera with them.

Over eleven brutal days, cholera killed three thousand in those two Canadian cities and

“Some died in the woods and were devoured by wolves,” writes the cholera historian J. S. Chambers.

The current state of the C&O Canal in Maryland testifies to its precipitous decline. The canal, which ferried coal from the Allegheny Mountains from 1831 to 1924, is now primarily used as a recreational area. The long ditch is mostly dry, and the old lockhouses, where lockkeepers and their families once lived, are in ruins.

Then we unleashed the buried energy of fossil fuels, sparking the Industrial Revolution. In less than a century—between 1820 and 1900—world economic production doubled. It’s continued to expand ever since.

Canals sowed the seeds of their own demise.

Whereas cholera sailed and steamed around the world, cholera’s children fly.40 * * * The growth of wet markets created the conditions for the SARS virus to spill over and adapt to humans, but it was the modern air travel network and a single establishment—

So much virus took leave of his body in that room that investigators recovered genetic evidence of the virus in the carpet months later.

Thanks to the miracle of air travel, one infected man seeded a global outbreak.

Surgical patients travel the world, carrying pathogens from operating rooms on one side of the globe to the other.

That’s why, historically, mosquitoborne pathogens don’t evolve to become waterborne ones,

Transmission of the pathogen Dicrocoelium dendriticum requires that snails incubate its eggs, ants drink the snails’ slime, and then grazing animals feed on the ants.

A pathogen such as Vibrio cholerae requires that humans regularly consume their own excreta. That’s good news because it means we can easily deprive it of transmission opportunities, for consuming each other’s waste is required for neither human survival nor the stability of our societies. The bad news is that sometimes historical conditions conspire to make even the most unnecessary and risky behaviors nearly inevitable.

city of New York had forsaken the practices of their ancestors. They immersed themselves so completely in each other’s waste that each likely ingested two teaspoons of fecal matter every day with their food and drink.5

this about-face had to do with the rise of Christianity in the fourth century A.D. The Greeks and Romans, not to mention the Hindus, the Buddhists, and the Muslims,