Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Biology

Causal Agent:

Balantidium coli, a large ciliated protozoan parasite.

Life Cycle:

Balantidium coli

Cysts are the parasite stage responsible for transmission of balantidiasis The number 1. The host most often acquires the cyst through ingestion of contaminated food or water The number 2. Following ingestion, excystation occurs in the small intestine, and the trophozoites colonize the large intestine The number 3. The trophozoites reside in the lumen of the large intestine of humans and animals, where they replicate by binary fission, during which conjugation may occur The number 4. Trophozoites undergo encystation to produce infective cysts The number 5. Some trophozoites invade the wall of the colon and multiply. Some return to the lumen and disintegrate. Mature cysts are passed with feces The number 1.

Life cycle image and information courtesy of DPDx.

  • Page last reviewed: March 17, 2015
  • Page last updated: March 17, 2015
  • Content source:
    • Global Health - Division of Parasitic Diseases and Malaria
    • Notice: Linking to a non-federal site does not constitute an endorsement by HHS, CDC or any of its employees of the sponsors or the information and products presented on the site.
Top