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Balantoides Coli

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Balantoides Coli, Balantidium Coli, Balantidium

  • Pathophysiology
  1. Balantidium
    1. Ovoid shaped Protozoa coated in cilia, and infect host Digestive Tracts
    2. Asexual reproduction via transverse binary fission
  2. Balantidium Coli
    1. Largest Protozoa to infect the human colon
    2. Balantidium Coli is ingested as cysts via pig feces-contaminated food or water
      1. Cysts mature into trophozoites covered in cilia
      2. Trophozoites traverse the intestinal tract where they embed in the intestinal wall
      3. Trophozoites feed on native gut Bacteria
  • Findings
  1. Often asymptomatic
  2. Diarrhea
  • Differential Diagnosis
  • Diagnosis
  1. Stool exam
    1. Ciliated trophozoites
    2. Balantidium Coli cysts
  • Complications
  1. Severe, fulminant Dysentery (untreated patients)
    1. May result in life-threatening colonic perforation
  • Management
  1. Tetracycline (first-line)
    1. Adults
      1. Tetracycline 500 mg four times daily for 10 days
    2. Children age >8 years
      1. Tetracycline 40 mg/kg/day (up to 2 g/day) divided four times daily (up to 500 mg/dose) for 10 days
    3. Children age <8 years
      1. Tetracycline is first line therapy may be used for up to 21 days in any age (per AAP)
  2. Metronidazole (alternative)
    1. Adults
      1. Metronidazole 750 mg orally three times daily for 5 days
    2. Child
      1. Metronidazole 35-50 mg/kg/day (up to 2 g/day) divided three times daily (up to 750 mg/dose) for 5 days
  3. Iodoquinol (alternative)
    1. Adults: 650 mg orally three times daily for 20 days
  • References
  1. Gladwin, Trattler and Mahan (2014) Clinical Microbiology, Medmaster, Fl, p. 351
  2. (2024) Sanford Guide, accessed on IOS, 7/11/2025
  3. Schuster (2008) Clin Microbiol Rev 21(4):626-38 +PMID: 18854484 [PubMed]