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It is possible that the main title of the report Balantidiasis is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • Balantidiosis
  • Balantidosis
  • Ciliary Dysentery

Disorder Subdivisions

  • None

General Discussion

Balantidiasis is a rare intestinal infection caused by the bacterium, Balantidium coli, a single celled parasite (ciliate protozoan) that frequently infects pigs but on occasion (rarely) infects humans. Some infected people may have no symptoms or only mild diarrhea and abdominal discomfort but others may experience more severe symptoms reminiscent of an acute inflammation of the intestines. Symptoms of Balantidiasis may be similar to those of other infections that cause intestinal inflammation, for example, amoebic dysentery.


Most people with Balantidiasis are asymptomatic or present mild symptoms. Some individuals may become acutely ill with abnormally high temperatures, nausea, vomiting, abdominal pain, and bloody diarrhea. Such conditions may result in the excessive loss of water from the body (dehydration) and extreme exhaustion (prostration), especially if B. coli attacks the intestinal lining causing inflammation and possibly "crater-like" areas of damage (ulceration). In very severe cases, the ulcers may be deep enough to puncture the intestinal wall (perforation) resulting in acute inflammation of the peritoneum, the membrane that lines the abdomen (peritonitis). Occasionally, the ulcer may diminish lung function.


Balantidiasis is a rare infectious disease caused by the single celled (protozoan) parasite Balantidium coli. This parasite may be passed directly to humans by contact with pig feces or indirectly by drinking contaminated water. Poor nutrition, a compromised immune system, or other illnesses may make a person vulnerable to more severe symptoms of this disease.

Affected Populations

Balantidiasis is a rare infection that affects males and females in equal numbers. It typically occurs in tropical regions such as Brazil, New Guinea, and southern Iran.

Standard Therapies

Balantidiasis can be diagnosed by laboratory testing of the stool. Immature B. coli parasites (trophozoites) are usually recoverable from the stool. A more complex and more invasive diagnostic method involves scraping the ulcer and examining the tissue for trophozoites.

The antibiotic drug most frequently used to treat Balantidiasis is tetracycline. When tetracycline cannot be given (i.e., allergy), replacement drug therapy may include the drugs iodoquinol or metronidazole. It is not necessary to isolate (quarantine) a person who has Balantidiasis. However, the feces of infected individuals must be disposed of so that they do not come into contact with drinking water or food supplies.

Investigational Therapies

Information on current clinical trials is posted on the Internet at All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

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Thoene JG., ed. Physicians' Guide to Rare Diseases. Montvale, NJ: Dowden Publishing Company Inc; 1995:528.

Fauci AS, et al., eds. Harrison's Principles of Internal Medicine, 14th Ed. New York, NY: McGraw-Hill, Inc; 1998:1204.

Sleisenger MH, et. al., Gastrointestinal Disease. 4th ed. Philadelphia, PA: W. B. Saunders Co; 1989:1171-72.


Garcia LS., Flagellates and ciliates. Clin Lab Med. 1999;19:621-38.

Juckett G., Intestinal protozoa. Am Fam Physician. 1996;53:2507-18.


Lucas SD., Invasive balantidiasis presented as chronic colitis and lung involvement. Dig Dis Sci. 1989;34:1621-23.

Currie AR., Human balantidiasis. A case report. S Afr J Surg. 1990;28:23-25.


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