Balantidiasis
Balantidiasis is an infectious gastrointestinal disease caused by the protozoan parasite Balantidium coli, which primarily resides in the intestines of various animals, including pigs and rodents. The infection occurs when humans ingest cysts of B. coli through contaminated food or water. Once inside the colon, the cysts transform into their active form, leading to intestinal damage and a range of gastrointestinal symptoms. Although not everyone infected will experience symptoms, individuals with weakened immune systems may face more severe manifestations, including diarrhea, vomiting, and dehydration.
This condition is most common in areas where direct exposure to animal feces occurs, particularly in environments associated with pig farming. Diagnosis typically involves assessing recent exposure history and identifying the parasite in stool samples or through colonoscopy. Treatment generally involves antibiotics like tetracycline or metronidazole, along with rehydration for those experiencing significant fluid loss. Preventative measures include maintaining good hygiene practices and avoiding contact with potentially infected animals. Balantidiasis emphasizes the importance of public health awareness, particularly in agricultural settings.
Balantidiasis
- ANATOMY OR SYSTEM AFFECTED: Gastrointestinal system, intestines, stomach
- ALSO KNOWN AS: Balantidiosis
Definition
Balantidiasis is an infectious gastrointestinal illness caused by the protozoan parasite Balantidium coli, a single-celled microbial organism that also infects pigs, rodents, horses, sheep, and goats.
Causes
Balantidiasis is caused by ingestion of B. coli, which reside in animal and human intestines and are excreted in feces in cyst (dormant) form. Humans ingest the cysts by eating contaminated food or water. Inside the colon, intestinal enzymes dissolve the cysts’ protective covering, releasing the active (trophozoite) form of the organism. The organism secretes a substance that breaks down the intestinal mucosa, causing ulceration and various other gastrointestinal symptoms.
Risk Factors
Balantidiasis occurs throughout the world but is most prevalent in locations where exposure to animal excrement is common, such as facilities where pigs or other infected animals are raised, slaughtered, or prepared as food. Living or working in such environments and poor sanitary conditions increase the risk of infection.
Symptoms
Not everyone infected with B. coli develops balantidiasis. Persons with impaired immunity or who are generally unwell because of malnutrition, cancer, or alcoholism are more likely than healthy persons to manifest symptoms. Balantidiasis can cause gastrointestinal diseases ranging from mild fever and stomach pain to severe diarrhea, vomiting, weight loss, and dehydration. Rarely, patients with balantidiasis develop a tear (perforation) in the lining of the intestines or develop pneumonia or inflammation of the lymph nodes.
Screening and Diagnosis
The patient’s recent history will typically reveal exposure to infected animals or contact with someone who has had gastrointestinal symptoms. B. coli cysts and trophozoites can be identified by stool culture or by colonoscopy, a procedure during which a flexible scope is used to examine and biopsy the intestines. If the patient’s symptoms indicate a need, an X-ray or a computed tomography (CT) scan may be ordered to examine the lungs or lymph nodes.
Treatment and Therapy
Balantidiasis is treated with the antibiotic medications tetracycline, iodoquinol, and metronidazole, together with intravenous fluids for patients who are dehydrated. Most patients experience a complete recovery with antibiotic therapy.
Prevention and Outcomes
Balantidiasis can be prevented by practicing good hygiene, especially when preparing food, and by avoiding environments where potentially infectious animals are handled.
Bibliography
"About Balantidium Coli Infection." Centers for Disease Control, 15 May 2024, www.cdc.gov/balantidium/about/index.html. Accessed 3 Feb. 2025.
Escobedo, Angel A., et al. “Treatment of Intestinal Protozoan Infections in Children.” Archives of Disease in Childhood 94 (2009): 478-482.
Feldman, Mark, Lawrence S. Friedman, and Lawrence J. Brandt, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. New ed. 2 vols. Philadelphia: Saunders/Elsevier, 2010.
Kapadia, Cyrus R., James M. Crawford, and Caroline Taylor. An Atlas of Gastroenterology: A Guide to Diagnosis and Differential Diagnosis. Boca Raton, Fla.: Pantheon, 2003.
Nilles-Bije, Lourdes, and Windell L. Rivera. “Ultrastructural and Molecular Characterization of Balantidium coli Isolated in the Philippines.” Parasitology Research 2 (2010): 932-113.
Schuster, Frederick, L., and Lynn Ramirez-Avila. “Current World Status of Balantidium coli.” Clinical Microbiology Reviews 12 (2008): 626-638.
Weller, Peter F. “Protozoal Intestinal Infections and Trichomoniasis.” In Harrison’s Principles of Internal Medicine, edited by Joan Butterton. 17th ed. New York: McGraw-Hill, 2008.