1.   Cryptosporidium is a coccidian protozoan parasite found in birds, fish, reptiles, and mammals.

2.   A protozoan parasite in the tick causes the disease by invading red blood cells.

3.   For example, spoiled food commonly contains toxoplasma, a protozoan parasite.

4.   He is trying to isolate the strands of protozoan parasites that infect the water supply and give children dysentery.

5.   Malaria spreads by a protozoan parasite that has three stages in its life cycle.