• Choose a category
• All
• Classic-Fiction

By Root 2939 0

story is wildly complex; it changes outward appearance with the alacrity of characters in a Shakespearean comedy. From the human point of view, though, the critical fact is that it is injected into our flesh by mosquitoes. Once in the body, the parasite pries open red blood cells and climbs inside. (I am here skipping several intermediate steps.) Floating about the circulatory system like passengers in so many submarines, the parasites reproduce in huge numbers inside the cell. Eventually the burgeoning offspring burst out of the cell and pour into the bloodstream. Most of the new parasites subvert other red blood cells, but a few drift in the blood, waiting to be sucked up by a biting mosquito. When a mosquito takes in Plasmodium, it reproduces yet again inside the insect, taking on a different form. The new parasites squirm into the mosquito’s salivary glands. From there the insect injects them into its next victim, beginning the cycle anew.

In the body, Plasmodium apparently uses biochemical signaling to synchronize its actions: most of the infected red blood cells release their parasites at about the same time. Victims experience these eruptions as huge, coordinated assaults—a single infection can generate ten billion new parasites. Overwhelmed by the deluge, the immune system sets off paroxysms of intense chills and fever. Eventually it beats back the attack, but within days a new assault occurs; some of the previous wave of parasites, which have hidden themselves inside red blood cells, have produced a new generation of Plasmodium, billions strong. The cycle repeats until the immune system at last fights off the parasite. Or seems to—Plasmodium cells can secret themselves in other corners of the body, from which they emerge a few weeks later. Half a dozen episodes of chills and fever, a bit of respite, then another wave of attacks: the badge of full-blown malaria.

Single-celled Plasmodium parasites burst out of dying red blood cells, beginning the assault on the body that leads to full-blown malaria. (Photo credit 3.1)

If the suffering caused by malaria today is difficult to grasp, it is almost impossible to imagine what it was like when its cause was unknown and no effective treatments existed. One can get a hint by reading the accounts of victims like Samuel Jeake, a seventeenth-century merchant in southeast England, who doggedly recorded every skirmish in his decades-long war with what we now recognize as malaria. To pick an example almost at random, here is Jeake on February 6, 1692, near the end of one six-month bout, stoically recording that he had been “taken ill the Seventh time: with a Tertian Ague [fever]; about 3h p.m. it began, & was of the same nature with my last which I had all January, but this was the worst.”

Feb. 8: A 2d fit which took me earlier & was worse.

Feb. 10: About noon a 3d fit. which shook me about 3h p.m. a very bad fit & violent feaver.…

Feb. 12: Before noon, a 4th fit. with which I shook about 3h p.m. & then went to bed: where had a very violent Feaver; this being the worst fit of all: my breath very short; & delirious.…

Feb. 14: About noon, a 5th fit.…

Feb. 16: About 2h. p.m. a 6th fit, very little, or scarce sensible, but sweat much in the night. And it pleased God that this was the last fit.

The respite lasted just fifteen days.

Mar. 3: About 4h. p.m. Taken ill the Eighth time: of a Tertian ague, succeeded by a Feaver & sweat in the night.…

Mar. 5: About 3h p.m. A 2d fit; worse than the former.

The attacks stopped nine weeks later. But malaria was not done with Jeake. The parasite, a superbly canny creature, can hide in the liver for as long as five years, periodically emerging to produce full-blown malarial relapses. Six months later, Plasmodium again massed in his blood.

Tertian fever of the sort experienced by Jeake is the signature of Plasmodium vivax and dium falciparum, which cause the two most widespread types of malaria. Despite the similarity of the symptoms, the two Plasmodium species have different effects on the body. After inserting itself inside red blood