Fig. 1

The complicated life cycle of protozoan parasites. The red and blue colors represent the life stages that occur in the vector and host of the parasite, respectively. (A) Apicomplexan parasite life stages are clearly identified in their reproductive cycle. The exception is the trophozoite stage, which refers to the stage where it draws nutrition or energy from an explicit host. (B) Mastigophora parasite life stages are based on the state of their flagellum. (C) Ciliophora and Sarcodina parasites have similar life stages that alternate from a cyst (usually made of eggs) to trophozoite. Simplified life cycles were referenced from the CDC [4]