What is Balantidum? Balantidium coli is a common protozoal parasite causing severe intestinal symptoms, so watch out for those monkeys at the zoo that throw their feces at you! It can also be passed by contaminated drinking water or eating vegetables which were improperly washed that have been contaminated with feces.


Protozoa-Balantidium (Water) 1

Picture of Balantidium cyst

Common Sources of Balantidium Infection—Water, feces contaminated vegetation that has been improperly washed, pigs, rats, dogs and non-human primates.

Protozoa-Balantidium (Water) 2

Balantidum lifecycle

Symptoms of Balantidium: Colic, straining to defecate, nausea, vomiting diarrhea, loss of appetite, bloody diarrhea, weakness. Infection can also be without symptoms. The incubation period is usually 3-4 days which means you need to be exposed 3-4 days previous before symptoms appear. This picture was taken from either a fecal sample (which was dyed) or from a colon biopsy.

Diagnosis and Treatment: Microscopic exam of fresh feces or sigmoidoscopy gatherings are needed to see the cysts and immature trophozoites. Metronidazole is the drug of choice for infections.

Prevention of Balantidium: A water filter is wonderful to prevent passage of the cysts. Note that bleach is not effective in killing the cysts, but iodine works and so does boiling.

Protozoa-Balantidium (Water) 3

Balantidium trophozoite