So we had this lecture on malaria on Thursday, and I decided that we needed a little object lesson to go along with it. Something interesting, and preferably tasty. It was a joint pathology + pharmacology lecture, so it needed to tie both of those together too.

I ended up making cookies that looked like malaria-infected red cells (photos below). And we had some tonic water to go along with the cookies (tonic water contains quinine, a drug that is still used today in the treatment of malaria). That way, the students could eat all the malaria-infected cookies they wanted, but they would be protected with quinine prophylaxis.

Here are the stages of the organism that ended up getting depicted in cookie form:

1. Gametocyte (see the photo above). The gametocyte is the sexual form of the plasmodium organism. In most species, it’s just a blobby thing. But in plasmodium falciparum, it’s a curvy, banana-shaped thing.

Which brings me to the title of this post. I never knew this (and hence could never remember which species had the banana-shaped gametocytes) – but falciparum comes from two Latin words: falx (which means a curve-shaped thing) and parum (which means to give birth to). That’s why the falx cerebri in the brain is named that way: it’s a curve-shaped structure.

The gametes in plasmodium falciparum (but not in other species!) are curved structures (falx) that are the sexual forms (give birth to) of the organism. Cool, huh? I don’t for sure whether that’s the reason the species was dubbed “falciparum” but it’s a pretty amazing (and fortuitous) coincidence if it was unintentional.

There you go: now you will always remember that falciparum is the species with the curved gametocytes.

2. Ring form (trophozoite). This is the first manifestation of the plasmodium organism in the red cell. All species have ring forms. They are kind of cute: little bluish circles with one or two reddish-purple chromatin masses.




3. Schizont. This form comes after the trophozoite. It is actually a whole bunch of little baby plasmodia all grouped together in one cell. Eventually, the red cell ruptures, and all the little babies (which are called merozoites now) come out, and start infecting other red cells. Some of the merozoites turn into gametocytes, which wind up in the mosquito, where they reproduce sexually and complete the life cycle of the plasmodium.


4. These cookies (below) are sickle cells, not plasmodial forms. I made them to remind the class that patients with sickle cell disease have a natural protection against malaria. If a patient with sickle cell disease does get infected, the infection is usually less severe, and is cleared more rapidly. Which explains why areas endemic for malaria have the highest incidence of sickle cell disease.