Why does malaria cause repeated chills and fever?

The periodic chills and fever associated with malaria are caused by the synchronized destruction of red blood cells by the Plasmodium parasite.12

As the parasites multiply within red blood cells, they develop into forms known as merozoites. When these cells rupture, they release the new generation of merozoites along with toxins into the bloodstream. This synchronized release triggers the body's immune response, resulting in the characteristic clinical attacks.12

The timing of these cycles depends on the specific species of parasite:
* 48-hour cycle (tertian malaria): Caused by P. falciparum, P. vivax, and P. ovale.12
* 72-hour cycle (quartan malaria): Caused by P. malariae.12
* 24-hour cycle: Caused by P. knowlesi, which can lead to daily fever spikes.12

If a patient is infected with multiple generations or species of parasites, these cycles may become unsynchronized, leading to more frequent or irregular episodes of chills, fever, and sweating.2