The Fever: How Malaria Has Ruled Humankind for 500,000 Years (7 page)

For centuries, Europeans could sustain little more than lightly manned trading posts in Africa.
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Malaria and other African diseases to which the Europeans had no immunity usually killed half of any group within a year of their arrival on the continent. That mortality rate, writes historian Philip Curtin, was “simply too high” for more intensive occupation.
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The British wouldn’t even risk exiling their convicts there. After the loss of its American colonies, British Parliament debated the notion of sending convicts to Gambia, but noting that such an exile amounted to a death sentence, they decided against it. They sent them to the terra incognita of New South Wales, Australia, instead.
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Most scientists agree that the Americas were malaria-free for thousands of years before Europeans arrived. The first human settlers may have had malaria parasites in their blood and livers when they crossed the Bering Strait eleven thousand years ago, but the parasites would have withered and died during the slow, frigid, mosquito-free journey.

When colonists from England arrived in the early 1600s, they had parasites roosting in their veins, and they encountered a land teeming with mosquitoes and wetlands, much more so than today. Swamp, bog, wetland, and marsh covered more than 220 million acres of the region that would become the United States.
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A beaver population roughly forty times that of today’s flooded even more land every year.
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And this temperate mosquito wonderland was connected
by a narrow isthmus to the tropical South American continent, which was dripping with dense mosquito-friendly rain forest.

The New World’s mosquitoes included an array of
Anopheles
species.
Anopheles crucians
spread its wings in the Floridian cypress swamps. Clouds of
Anopheles punctipennis
swarmed the continent’s great temperate forests, and
Anopheles quadrimaculatus
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gathered at the edges of sun-dappled lakes. In Europe, malaria parasites had rendered such watery environs uninhabitable, but Native Americans were able to exploit the lush and abundant wetlands to the fullest.

In the spring of 1607, the English sailed gingerly into the Chesapeake Bay and up the James River. Wary of attack from the local Algonquins—as well as from the Spanish, farther south—they denied themselves the dry, fertile ground farther inland in favor of a small island in the river, separated from the mainland by a narrow channel. Whatever they gained in strategic security, though, the Jamestown colonists lost in vulnerability to the local
Anopheles
, for marshes covered the low-lying island, and the mosquitoes that hatched from them likely started biting the colonists not long after their arrival.
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The English called vivax malaria the ague (the word rhymes with “plague you”), and we know that at least one of the Jamestown settlers was probably infected with it when he arrived. Shortly before his departure for Jamestown, Nathaniel Powell described his malarial state in a letter: “I have not yet lost my quartane Ague,” he wrote, “but as I had him yesterday so I expect him on Thursday next.”
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Given the relatively quick transit time across the Atlantic (compared, at least, with the earlier traverse of the Bering land bridge), infected colonists such as Powell almost certainly ferried viable vivax parasites to Jamestown.

Malaria’s arrival wouldn’t have emerged as a major force to be reckoned with at first. Measles and smallpox destroyed the local native peoples with cruel efficiency, while diseases of filth—typhoid, dysentery—ransacked the Jamestown settlers.
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But those pathogens don’t have much staying power. Measles and smallpox burned through all the virgin blood available to them and then receded to
near oblivion. And as soon as conditions in new settlements improved even marginally, dysentery and typhoid started to recede, too. What the settlers had to live with, in the long term, was malaria, cresting like a shark on the undertow.

By the mid-1600s, the surviving Virginia settlers took over the local Native Americans’ drier, more fertile lands, but in an age of water travel they could never stray too far from the mosquito-ridden lowlands by the rivers and bays, and by the late 1600s, vivax malaria had become endemic. Living in Virginia required suffering what residents called a “seasoning”—that is, “two or three small fits of a feaver and ague,” as one settler wrote in 1687.
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The penalty of “seasoning” and the subsequent debility of chronic malaria infection reduced Jamestown and the other Chesapeake colonies to a sorry state. Chroniclers of the day described the survivors’ dirt-floored, windowless houses riven with cracks, and their farms littered with rotting stumps.
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They’d be lucky to pull in three pounds sterling in annual profit.
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Those who did prosper—such as Powell, who joined the governor’s council in 1619—enjoyed a modicum of immunity to
P. vivax
. Like Powell, many had grown up in low-lying Kent and Essex, two of the most malarious counties in England.
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While the Chesapeake colonies suffered the consequences of their malarial contamination, the absence of the disease leveraged the unlikely success of those European settlers who headed farther north. New England’s generally cool weather slowed the development of the malarial parasite so that its life cycle far exceeded the average life span of an infected mosquito. (At sixty-five degrees Fahrenheit,
P. vivax
’s reproduction inside the mosquito slows to a twenty-day cycle, and
P. falciparum
’s to twenty-three days, while the average anopheline might live just over a week.) In addition, the rocky creeks and forested hills of New England provided few suitable habitats for the most efficient malarial mosquitoes.
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The Pilgrims and Puritans who settled the northern colonies knew the colder climate would be healthier. “A sup of New England’s
aire is better than a whole draught of Old England’s ale,” wrote one New England colonist in 1629. “Experience doth manifest that there is hardly a more healthfull place to be found in the world that agreeth better with our English bodyes.”
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Indeed, although they suffered the hostility of the native peoples and the pioneer’s diseases of filth like the southern colonists, and had to put up with New England’s marginal growing conditions and brutal winters to boot, the New England colonists experienced a boom, right from the beginning. Within decades of settlement, the relatively small numbers of settlers there had created colonies as large as those in the Chesapeake Bay. By 1700, some twenty thousand settlers in New England, through birth and minimal immigration, grew colonies as big as those in Virginia and Maryland, where more than 140,000 migrants had landed. The average life expectancy hovered around sixty years, with each new generation doubling the size of the population.
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The superior disease environment of the North—in particular, its relative freedom from malaria—spelled the difference.

Oceans of ink have been spilled on the cruelty and waste of the so-called triangular trade that European colonists established in the Americas over the following centuries. For the love of sugar, easily grown in the tropical Americas, and silver, mined from its lush deposits, millions of Africans were shackled and enslaved and shipped across the sea, and the products they created were looted and pirated across the sea to sate Europe. That bloody trade, which cost millions of lives and disrupted countless cultures and economies, spread over four continents, and we tremble from its reverberations to this day. Malaria did not create it. But
Plasmodium
certainly helped carve its harsh contours.

By the mid-sixteenth century, labor had become a problem in the New World colonies. The local native peoples, enslaved to work the sugarcane crop and the silver and gold mines, were dangerously vulnerable
to easily transmissible Old World germs such as smallpox and measles, broadcast on the Europeans’ breath, coughs, sneezes, and dirty blankets. Wave after wave of disease—a single smallpox epidemic during the 1560s, for example, felled thirty thousand native slaves in Brazil
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—soon denuded the cane fields of workers.
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It might have seemed reasonable, at this point, to transplant American sugarcane colonies to West Africa, which was similarly amenable climatically and much closer to European markets. But falciparum malaria had already rendered such arrangements untenable.
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Instead, shorn of Native American slave labor, European colonizers in the New World turned to slave labor from Africa. A small Portuguese trade in African slaves had started in the 1400s, selling African slaves captured in wars to other African states. First the Spanish and Portuguese, but soon the English, French, and Dutch as well, increasingly turned to slaves to sate their labor needs in the American colonies.
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But by the eighteenth century, Africa’s trickle of war captives and outcasts would no longer suffice to service the increased demand for slaves. Soon raiders started plunging deeper into the interior of the continent to capture the terrified sons and daughters of peaceful farmers and villagers, to forcibly sell them into slavery. For fear of the raiders, whole villages in Africa abandoned their lands and long-established trade routes, and the exquisite balance between man and parasite forged over millennia was abruptly ruptured.
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The new labor arrangement proved costly for the Europeans as well. Ferrying slaves from Africa to the West Indies, and the West Indies sugar they produced back to Europe, involved a tremendous amount of difficult and time-consuming shipping—and thus exposure to disease. Slave raiders could avoid contact with foreign strains of
P. falciparum
and other diseases by passing their captives along a chain of traders, from the interior to the waiting ships on the coast. But the crews aboard the slave ships were dangerously vulnerable.
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The burden of disease decimated state-backed efforts by the Dutch, English, and French to monopolize the slave trade. Instead,
ad hoc bands of merchants funded perilous voyages from Europe to Africa to the West Indies and back, coercing their crews into the job and not expecting to make more than one death-defying trip in a lifetime. As a result, crews aboard the slave ships usually had to wait for months at slave ports while their holds filled with screaming captives, who trickled in at a rate of two to three a day. Forty-five percent of European sailors on slave ships died, more than in any other trade of the era,
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from the “noxious vapour, arising from the swamps,” as a slave-ship surgeon of the time called it. “This trade,” he wrote, “may justly be denominated the grave of seamen.”
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Despite these conditions, between 1700 and 1800, European slavers brought some six million bound and shackled Africans to the Americas. With falciparum parasites roosting in their veins, they changed the face of the Americas forever.
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While malaria-experienced Europeans knew of the dangers of malarial fever, and the particular deadliness of Africa’s fevers, they had no way to predict what would happen upon flooding the Americas with falciparum-ridden Africans.

Sixteenth-century Westerners didn’t have a specific definition for the disease of malaria. They didn’t know about the parasite or the mosquito that carried it, and so their experience of malaria led them to consider it primarily a disease embedded in the landscape. Western medical authorities of the time attributed many diseases, including malaria, to smelly vapors they called miasmas, which purportedly rose from stagnant water, putrefying vegetation, and animal remains. According to miasmatic theory, miasmas grew more dangerous in warm climates, where everything got stinkier faster, whether it was spoiling food or decomposing vegetation. This was why, as Plymouth colony leader William Bradford wrote, “Hott countries are subject to grievous diseases.”
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The diseases of the hot climates frightened sixteenth-century Europeans so much they thought that sudden exposure to heat could literally melt the fat inside a person.
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The potency of miasmatic theory, which held sway from the Middle Ages until the end of the nineteenth century, may have derived partly from how well its teachings helped explain and prevent malaria. Before the nineteenth century, when miasmatic theory inspired sanitationists to separate food and water from waste, vanquishing many infectious diseases in the process, the teachings of miasmatism were relatively useless. Miasmatism’s admonition to avoid stagnant waters and stinky vapors did little to help people stay away from unwashed hands and food, which is what gave them dysentery and typhoid. Nor did it encourage them to avoid exposure to the exhalations of the sick, which gave them measles, smallpox, tuberculosis, influenza, and pneumonic plague. Miasmatic theory didn’t help much with leprosy, either, which people got from constant, long-term contact with sufferers, or with typhus, which they contracted from lice, or syphilis, which is transmitted through sexual contact.

It did help protect people from malaria, however. The miasmatic theorists may not have known it, but the larvae of many
Anopheles
mosquito species live in stagnant waters, feeding on and hiding from predators under the rotting vegetation that endows swamps and wetlands with their distinctive sulphurous odor. Minimizing exposure to this malodorous air—by avoiding swamps and closing doors and windows, as miasmatism suggested—certainly would have helped people avoid mosquito bites. Indeed, according to miasmatic theory, it wasn’t the miasma itself that was poisonous, but rather the “miasmata,” or bits of debris, it carried within it. Miasmatism’s prediction that warm climates threatened greater disease was especially true for malaria, for higher temperatures allowed the parasite to develop faster, ensuring that more infected mosquitoes would transmit the disease.