Question

Name the toxin responsible for the appearance of symptoms of malaria in humans. Why do these symptoms occur periodically?

Answer 1

The toxin responsible is haemozoin, released when the parasitised red blood cells burst. The symptoms occur periodically because the parasites multiply synchronously inside the RBCs and burst them at fixed intervals. Depending on the species, the RBCs burst every 48 hours (P. vivax, P. falciparum) or 72 hours (P. malariae), releasing a fresh batch of toxins and causing fever at that same time each cycle.