Balantidium coli

Balantidium coli is a large protozoon. The trophozoite measures 30-200 m x 40-60 m. The whole surface of the trophozoite is dotted with countless cilia. These are very characteristic and because of this, it is classified as a ciliate (compare with Paramecium). Balantidium coli is the only ciliate pathogenic to humans. The cysts are oval and measure approximately 45 x 60 m. As yet there are insufficient data concerning this organism. It is a commensal of pigs. Transmission occurs from pigs to humans and from human to human in poor hygiene situations, also via water or food contaminated with cysts, including poorly cooked pork sausages. The infection is cosmopolitan, rare, yet locally prevalent, e.g. in Papua New Guinea and in tropical Africa. As with amoebiasis the infection may be intraluminal and latent or invasive in the intestinal wall and symptomatic. In the invasive forms ulcerations of the intestinal wall are found, quite similar to those of amoebiasis, with the same complications and the same clinical forms. Liver abscesses caused by B. coli have been observed but are extremely rare. Diagnosis is parasitological by direct stool microscopy or enrichment techniques. Treatment is not always simple. Tetracyclines (10 days) have been used as well as imidazoles in high doses.

Category: Medicine Notes