The Fever: How Malaria Has Ruled Humankind for 500,000 Years (14 page)

In 2006, researchers found the malaria vector
Anopheles arabiensis
on the slopes of Mount Kenya, where the snow cover has started to melt, for the first time ever. Some fifteen thousand tourists visit the Kenyan highlands every year, regularly introducing malaria parasites to the region. Researchers predict that malaria prevalence could rise to 80 percent.
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Mathematical models predict other extensions. For example, according to one model, climate change could create amenable conditions for
Anopheles farauti
from the sparsely populated northern tip of Australia to extend four hundred miles southward into Queensland’s population centers and tourist hot spots. The last known outbreak of malaria carried by local mosquitoes in Australia occurred in the Northern Territory in 1962. There just aren’t enough people living up there to sustain the parasite over time. Not so farther south, where a constant influx of people from malarious Papua New Guinea and the Torres Strait Islands would ensure a robust supply of malaria parasites. Queensland has so far been unable to control other mosquito-transmitted diseases, such as dengue and Ross River fever. If the
Anopheles farauti
mosquito starts passing on malaria parasites in Queensland, the result would be far different from that in the sparsely populated far north.
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Now that we know the delicacy of malaria’s ecological stability, could we preserve each mosquito-ridden waterway and marsh and microhabitat in pristine stasis, tiptoeing so lightly on the landscape that nary a pebble ripples its glassy surface? It is hard to imagine. Such a
nonintrusive existence may once have been possible, during those early days when the global population consisted of a few bands of hungry hunters hauling themselves across the savannah. There’s just too many of us now. Even if we surrender our machines, blunt our saws, and fill our mines, the appetites of our hungry, growing population will continue to scar the terrain. We will clear the land, furrow the soil, and stomp into warm mud—and by so doing, risk tearing into malaria’s gauzy architecture.

Whether climate change or any of the other ecological disruptions we’ve set in motion will worsen malaria is just speculation, for now. But one thing is clear. We manipulate the environment as surely as beavers build dams, creating a constant stream of new and altered conditions that mosquitoes and parasites can exploit. When they do, the malarial shock waves spread far and wide.

An entire shelf in my medicine cabinet is lined with orange bottles of malaria pills. I get them from my regular physician. I tell her I’m traveling to a malarious region; she writes me a prescription; I get it filled at the local pharmacy; an insurance company pays for most of it; I chip in a few bucks. It’s a painless procedure.

Sometimes I get the kind you have to take every day; sometimes the ones you take once a week. Either way, when I visit malarious areas, I pry open the plastic caps and wash down the pills with near-religious conviction. I pack boxes of chocolates, which I store in tropical cupboards, so I can slide the pills into the half-melted sweets for my kids. They actually look forward to their doses.

People vary in their devotion to the drugs, of course. A few, such as an American entomologist I met in Cameroon, are super-careful, like me. When he travels in malaria territory, he rotates between two or three different drugs, and drinks gin with tonic—spiked with antimalarial quinine—just to be extra safe. “I’m a man with a belt
and
suspenders,” he says.
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Others don’t bother. I’ve met as many malariologists who don’t take the drugs as do. Terrie Taylor didn’t take anything one year, and promptly got infected in Malawi. She was very sick for a few days, she tells me, and remembers lying in
front of the fireplace for half an hour, debating the “relative discomfort” of lying on her side versus turning over onto her back. Now she always takes the drugs, because it is just “inconvenient” to be that sick. The worst thing, she says, is that she craved Orange Fanta. “Orange Fanta!” she exclaims.

Some pick and choose, depending on unrelated whims. A poet I know prefers the older drugs, which have the side effect of provoking vivid dreams. He likes the subtly psychotropic effect. “It’s good for writing poems,” he says.

All of which is to say that antimalarial drugs can prevent malaria as well as treat it, and everyone knows this. All we have to do is open our mouths, and our chosen chemical assassins will seek out and destroy the malaria parasites roosting within us. As prophylactics, antimalarial drugs can be up to 98 percent effective at preventing malaria infection.
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As treatment, they’re crucial. Antimalarial drugs reduce the risk of death from falciparum infection by fifty-fold, sending the parasite levels in the blood plummeting. Even someone sick with life-threatening malaria can reduce their risk of death five-fold with decent antimalaria drugs.
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So these days, if a Westerner gets sick from malaria, or dies from it, the question naturally arises,
Why didn’t he take the drugs?
The inverse—that the poor die from malaria because they can’t get the drugs—we take as a given. But in fact, that isn’t really true. Antimalarial drugs are available at local vendors across the malarious world. Synthetic antimalarial medications, available since the mid-twentieth century, can be bought cheaply all over the world. And plants that grow like weeds produce antimalarial compounds, including one that is currently considered a wonder drug. People have known about many of them for almost as long as we’ve had malaria.

Good drugs—some half as effective, twice as expensive, three times harder to get—have vanquished countless other scourges, from leprosy to rheumatic fever. But despite the range of effective parasite-killing drugs in our arsenal, despite the world being awash in antimalarial medications, malaria flourishes. In the battle between
Homo
sapiens
and
Plasmodium
, the parasite is winning. It has eluded attempts to capture it by drug every time.

Our use of medicines to treat malaria dates back to the beginning of human history. Long before the first mosquito bit a human, plants waged a silent, slow-motion war against insects, microbes, and rival plants by producing toxic chemicals.
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They produce them in their leaves, stems, roots, and barks, and exude them when cut, or attacked from within. The liquid drips and chemical pongs of these silent, primeval green battles play out all around us.

Since the earliest times, we’ve consumed plants to harness the pharmacological potency of their chemicals (called secondary compounds to distinguish them from those primary compounds that do the work of brute survival). The secondary compounds of plants such as belladonna, poppy, and foxglove—aka atropine, opium, and digitalin—captivate human biochemistry in powerful ways, too.

In the normal course of things, malaria parasites that live inside insects, mammals, and birds don’t encounter these botanical bio-weapons. But some of those compounds dripping down leaves and branches can do serious damage to malaria parasites. Perhaps it’s just a side effect. Then again, 10 percent of the parasite’s five thousand proteins retain their algaelike chemistry and remnant chloroplasts. In an earlier life,
Plasmodium
photosynthesized, too.

The shrub mululuza is one of many plants with secondary compounds that provide relief from malaria. Chimpanzees chew on its bitter leaves, as did our African ancestors, suggesting the curious idea that our knowledge of botanical malaria medicines—like malaria itself—may have survived the evolutionary hop from ape to human.
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Clove, nutmeg, cinnamon, basil, and onion similarly all assuage
Plasmodium
’s appetite, making the body’s repair of damage from free radicals—oxygen molecules untethered to hemoglobin—more difficult. This, paradoxically, can help destroy malaria parasites by exposing infected cells to the armies of free radicals that malaria infection
unleashes, and may explain why for millennia people sought out and added these nutritionally empty products to their diets.
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One of the very best drugs for malaria can be found thousands of miles away from malaria’s African cradle, in the bark of the cinchona, a tree that clings to the slopes of the Andes. Like mululuza and basil, cinchona bark started out as a traditional medicine used by the locals for myriad ailments involving fever and chills.
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The bark teems with complex alkaloids, most likely used by the tree to defend itself against pathogens and herbivores.
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One of them, quinine, has a striking effect on the
Plasmodium
parasite, interfering with its digestion of hemoglobin. The result: the feasting parasite is poisoned with the undigested toxic residue of its own meal.
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While it can’t prevent malaria infection, quinine circulating in the body can prevent and mitigate illness.

Quinine dropped upon a world beset by malaria like rain on a dry sponge. “Had our bread failed, our wells and the river dried up, we could have endured it,” wrote one typical nineteenth-century quinine enthusiast from Michigan. “But to be without cathartic pills and quinine . . . was worse than a bread and water famine.”
¹⁰
The drug was considered a “sovereign remedy,”
¹¹
a “divine medicine.”
¹²
And when, finally, in the nineteenth century, quinine was made widely available, the Brits were at last able to penetrate malarious Africa. Historians credit the drug, along with filtered water, for Britain’s successful 1874 offensive against the Asante Empire in Ghana,
¹³
ushering in a brief but long-awaited period of European colonization of the African continent.
¹⁴

But despite being a wonder drug for malaria and nearly a half-millennium of usage, quinine barely made a dent in the global burden of malaria.

Jesuit missionaries who’d noticed the bark’s effect against the disease in South America introduced it into malaria-plagued European society in the 1630s.
¹⁵
Malaria ran rampant in Europe, and cinchona
bark was quite possibly the best and most effective medicine ever known. Most of the other medicants then available, such as opium, had a vague, generalized effect on illness. In contrast, cinchona bark could cure malaria effectively and with surgical precision.
¹⁶

It took fifty years for it to gain its rightful stature. Having been introduced by the Jesuits, cinchona fell under a cloud of anti-Catholic sentiment. The Protestant English scoffed at the bark, deriding it as “Jesuit’s powder.” Elites such as Oliver Cromwell, who successfully led the bloody overthrow of the British monarchy, pointedly eschewed the bark. He died of malaria in 1658, twenty years after the Jesuits brought cinchona to Europe.
¹⁷
European elites did, however, approve of a remedy called “Talbor’s Wonderful Secret,” which everyone, from the son of Louis XIV to the Queen of Spain, extolled. Word got out that the secret remedy got its kick from cinchona, aka the reviled Jesuit’s powder, in 1682.
¹⁸

The trouble was, only the tiniest trickle of the stuff could be had. Up until the late nineteenth century, worldwide demand for cinchona mostly had to make do with whatever bark could be stripped off the wild cinchona forests in the far-off and perilous Andes.
¹⁹
Political rulers in the region considered the cinchona tree to be their exclusive property. Nevertheless, European entrepreneurs and explorers eager to produce their own lucrative stands of cinchona repeatedly attempted to pirate the seeds out of the Andes, with a nearly comic chain of calamities.
²⁰
The tree and its seedlings, accustomed to steep, forested mountainsides, proved too delicate for long, dank sea voyages across the Atlantic. If it wasn’t the heat, piracy, and theft, fires and storms foiled their attempts.

Shortages reigned. Even the most richly endowed enterprises—the American war effort against Britain, the British drive to end the African slave trade—had to ration their quinine. During the American Revolution, the Continental Congress managed to acquire a paltry three hundred pounds of the bark. George Washington’s bout of malaria got eight doses of bark, but the regiments of soldiers—including New Milford’s Elijah Boardman—had to make do with
days of treatment with bowel-purging antimony and mind-dulling opium before their bosses would tap the precious cinchona supply (another reason why Boardman and others sickened on the battlefield and on the trek back home, broadcasting the parasite throughout the land).
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The abolitionist British parliamentarian Thomas Fowell Buxton took “ every precaution which human ingenuity could suggest” to keep healthy on his 1841 expedition up the Niger River to press African leaders to stanch the slave trade.
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But his party, too, had to ration quinine. To prevent malaria, they relied mostly on copious volumes of coffee, reserving their quinine supply for a few shots in their wine.
²³
(Physicians long suspected that coffee had antimalarial properties, which seemed to explain why coffee-drinking French colonists suffered less malaria than tea-drinking English ones, and may have helped inspire a nation of American tea drinkers to switch allegiances.
²⁴
) Coffee having failed them, disease and death ran so rampant that the expedition was called back home.

A single day’s worth of quinine, which French chemists Joseph Caventou and Pierre Pelletier had figured out how to extract from cinchona in 1820,
²⁵
cost about three dollars between 1830 and 1884, which translates to more than sixty 2006 dollars.
²⁶
The moneyed and powerful could at least hoard a few precious grains, but everyday folks had to make do with the cheap knock-offs that littered the market: quinine-spiked pills and potions and chill tonics, which claimed curative powers at a fraction of the price of the real thing. Many of these contained insignificant quantities of quinine, dissolved in copious quantities of alcohol. While not particularly effective at treating malaria, at least they provided plebes with an otherwise verboten drink or two.
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