As a result of this activity, pseudopodia are formed at the front end of the moving cell. Movement in the ciliates is accomplished through the action of cilia which cover the surface of the organism and function somewhat like oars. Flagellates movement is accomplished through a whip-like action of the flagella. Protozoan diseases can cause serious health problems in people. Some of these include, amoebic dysentery which is caused by Entamoeba histolytica , an amoeboid protozoan.
Transmission is oral- fecal such as from ingestion of contaminated lake water.
Giardiasis is another disease and it is caused by Giardia lamblia , a protozoan spread by the oral- fecal route. Cysts of the organism, from contaminated water or food are ingested. African sleeping sickness is caused by Trypanosoma brucei and is spread by the tsetse fly. Cattle and other livestock, as well as the tsetse fly, serve as reservoirs of the protozoan. Chagas disease is caused by Trypanosoma cruzi .