Step 1 : Introduction to the question "What disease results from an infestation by the parasitic protozoan Plasmodium?"
...Plasmodium is a type of parasitic protozoan. It infects the red blood cells of humans and other mammals, as well as birds and reptiles. It occurs worldwide, but is especially fond of tropical and temperate zones. It is the causative organism in the disease malaria and transmitted by female mosquitos. There are actually five species of Plasmodium that cause malaria. The parasite attaches itself to the red blood cells, destroying them and releasing toxins into the blood stream. This causes the periodic chills-and-fever cycles typical of malaria. Source: Britannica.com