Those of us in the southwest of Ethiopia — what the Peace Corps folks refer to as the “Jimma Loop” — had a regional training this past week. We covered quite a few different topics, but one that touched me personally was a discussion on our last day about malaria.
A CDC/Ethiopia doctor reviewed the science behind malaria infection and discussed ways we could work with our partners to combat the disease: for example, make sure the bed nets distributed by USAID were being properly used and maintained, try to figure out barriers to their proper usage, report malaria outbreaks and medication shortages. Malaria is a serious problem, with about 9 million cases each year. It particularly harms children and pregnant women: according to UNICEF, malaria causes up to 20 percent of deaths of children under 5 years old.
We’d gone over the technical aspects of malaria before, but as our presenter reviewed the infection cycle, I had flashbacks to swatting away mosquitoes almost constantly during our stay in Jimma. I take a daily dose of doxycyline, a malaria prophylaxis, but it’s not one hundred percent effective, even when taken religiously — and my ability to take a pill at the same time daily is…imperfect. There are only a few reported cases of malaria in my town each year, and so most of the time I don’t worry about it too much. As I looked around the stifling meeting room, though, I could see others’ minds go in the same direction as mine: what if I got malaria from one of the dozens of mosquito bites with which I’m sure to leave Jimma?
There are two strains of malaria in Ethiopia, plasmodium falciparum and plasmodium vivax. The latter strain doesn’t usually kill you; the former, when untreated, usually does. P. falciparum is transmitted by the female Anopheles mosquito, which typically bites only between dusk and dawn — that’s why the use of insecticide-treated bed nets is so effective in curbing the disease. Fun fact: mosquitos can see infared, so they find you at night by your heat, as well as the carbon dioxide you exhale. They’re evil little monsters, no?
When Mrs. Anopheles bites an infected human, she sucks up little baby malaria parasites (plasmodium gametocytes), which then mature and release sporozoites inside the mosquito. The process takes about 10-14 days, and the mosquito goes about its business of sucking blood. Once the sporozoites are released inside the mosquito, its next victim is screwed, because she’ll no longer just be taking a little dinner, but leaving a little present behind. Those sporozoites will swim on over to the unlucky human’s liver, where they invade the liver cells for their own devious ends.
The sporozoites form merozoites in sufficient quantities to rupture the occupied liver cells, then spew into the bloodstream and move onto their next conquests: red blood cells. They repeat their pattern of taking over a cell, then bursting out all over the place — though in this case, their prison break alerts your immune system and causes fever and chills. Some of those nasty little suckers develop into gametocytes, and hang out, waiting for a mosquito to come along and perpetuate their vicious cycle.
As insidious as this parasite is, I can’t help admire its elegance. I mean, it evolved in such a way that it requires two different kinds of organisms to survive and procreate — the mosquito and the human — and it does so rather effectively.
If you’re in a malarious area or have been in the past week or two and have a fever, you should probably go and get yourself tested. Currently, all Ethiopian health care facilities should have rapid diagnostic tests, which are just like pregnancy tests — for plasmodium. You prick a finger and put a little blood on a slide, then wait 20 minutes. A little line shows up to show you the test worked properly. That line will have company if you have malaria: if it’s in one column, you have p. falciparum, if it’s in the other, p. vivax (or, of course, one in each if you’re infected with both strains). The ability to diagnose not only the presence of malaria but also the correct strain means the ability to select the proper treatment, since each strain requires different medications.
Coartem is a fancy (and relatively expensive) malaria treatment that’s only necessary for the treatment of p. falciparum. It will work in fighting p. vivax, but it’s important to limit use of Coartem, not only to ensure there’s a enough supply to treat the cases of potentially fatal p. falciparum, but also to prevent malaria from becoming drug resistant. P. vivax can be treated with chloroquine, which is much easier to come by.
I don’t really think I’ll get malaria — I’m on the prophylaxis, I sleep under a bed net, it’s not peak malaria season, and malaria is uncommon in these parts, anyway — but if I do, I shouldn’t have any problems getting treated. I live in a larger town with a hospital, and so even if everyone is out of rapid diagnostic tests, I can still be diagnosed by a lab tech who looks at my blood under a microscope. I have both malaria medications in my Peace Corps-issued medical kit. And, as a healthy adult on a prophylaxis, I’m not likely to have the kind of malaria that strikes suddenly and incapacitates its host. I’d probably just feel like I had the worst flu ever.
Just in case, though, I’ll be taking my temperature at the first sign of a fever — at least for the next few weeks. Unlike p. falciparum, a little caution never killed anyone.