Balantidium coli



Physiology and Structure:

Its life cycle is simple and involves ingestion of infectious cysts, excystation and invasion of trophozoites. The oval trophozoite measures 30-100 micrometers in width. the trophoziote is present in two nuclei, a large kidney-shaped macronuclues and a small  round micronuclues located ajoining to the macronuclues.


Extracted from: Essentials of Human Parasitology


Extracted from: Essentials of Human Parasitology


Life Cycle:


Extracted from: Essentials of Human Parasitology


Clinical Syndromes:

Asymptomatic carriage of B.colu can still exist with other protozoan parasites. Symptomatic diesease is characterized by abdominal pain and tenderness, nausea, anorexia and watery stools with blood and pus. The incidence of infection of B.coli is low, although the parasite is distributed world wide. Pigs are a good reservoir to breed the parasite. The infection can be transmitted by fecal-oral or from person-to-person.

Chronic infection may occur and some patients are asymptomatic. Moreover, infections may occur in the liver, lungs and other organs but these are usually rare.


Laboratory Diagnosis:

The trophozoite is rather large as it measures up to 200 micrometers in length and 70 micrometers in width. Macronuclues is the prominent internal structure which is usually present. B. coli is a large organism compared with other intestinal protozoa and is usually found in fresh, moist microscopic preparations.

Treatment, Prevention and Control:

  • Good personal hygiene and proper sanitary conditions are effective measures in prevention of the spread of this disease.
  • Drugs such as iodoquinol and metronidazole are alternative antimicrobials.