Balantidium coli

• Balantidium coli

  A protozoan parasite that causes balantidiasis
• Classification of Balantidium coli

  • Protozoa
  • Ciliophora
  • Ciliates

  
• Balantidium coli


  • It is the largest protozoan parasite
  • It is the only known pathogenic ciliate
  • Common among pigs
  • Could be found among monkeys in the tropics
  • Usually found in the large intestines (Colon)
  • Can cause life-threatening colitis
• Cyst

  Infective stage found in stools of asymptomatic/chronic infections
• Cyst


  • Round in shape
  • Refractile
  • Has a smooth thick wall
  • Presence of macro and micro nuclei when stained
• Trophozoite

  The vegetative form of Balantidium coli

  
• Trophozoite

  • Oval in shape
  • Usually macroscopic
  • Has rapid revolving motility (spiral motility)
  • Has 2 nuclei (somatic/germinal)
  • Macro-nucleus is bean/kidney shaped
• Balantidium coli has a worldwide distribution
• Human infections are found among institutionalized groups with low levels of personal hygiene
• Forms of Balantidium coli infection

  • Asymptomatic carrier state
  • Acute colitis
  • Acute fulminant colitis
  • Chronic infection
• Symptoms of acute infections

  Severe diarrhoea<|>Dysentery<|>Tenesmus<|>Vomiting<|>Headaches<|>Nausea<|>Anorexia
• Invasion by Trophozoites

  • Invade the distal portion of the ilium
  • Invade colonic mucosal, submucosa, and muscular layer
  • Leads to intense mucosal inflammation and ulcerations
• Ulcers caused by Balantidium coli

  • Round, ovoid or irregular in shape
  • Usually infected with bacteria
  • Leads to severe diarrhoea and dysentery
• Mechanisms of invasion are not well known but the involvement of enzymes like Hyaluronidase is suspected
• The diarrhea caused by Balantidium coli is similar to that seen in cholera
• Diagnosis of Balantidium coli infection

  1. Stool RE (wet mounts)

  2. Trophozoite found in dysenteric/diarrhoeic stools

  3. Cysts found in semi-formed stools

  4. Serological tests could also be used

  
• Drug of choice for Balantidium coli

  Tetracycline 500mg X 4x daily for 10 days
• Other drugs the parasite is sensitive to

  • Metronidazole
  • Ampicillin
  • Bacitracin
  • Paramomycin
• Preventive measures for Balantidium coli

  • Good personal hygiene
  • Good sanitation measures
  • Good supply of potable water