Excystment by sporozoites of malaria parasites

Abstract

IT IS widely assumed that the mature oocyst of the malaria parasite bursts and liberates the sporozoites en masse1 although studies on the intestinal coccidians have clearly shown that the sporozoites escape through the wall of the sporocyst, a structure analagous to the oocyst of malaria parasites, by way of specialised pores2-4. During a scanning electron microscope study of the sporogonic cycle of the rodent malaria parasite Plasmodium yoelii nigeriensis in the vector Anopheles stephensi, evidence has been obtained which suggests that excystment of the sporozoite may occur by a method differing from both those described above. © 1974 Nature Publishing Group.