A placebo-controlled treatment trial of Blastocystis hominis infection with metronidazole

J Travel Med. 2003 Mar-Apr;10(2):128-30. doi: 10.2310/7060.2003.31714.


Blastocystis hominis, previously considered a harmless yeast, is now classified as a protozoan inhabiting the human intestinal tract. The pathogenicity of B. hominis remains controversial and is currently the subject of extensive debate.1- 5 As a result of the uncertainty surrounding the pathogenic role of B. hominis, large-scale treatment trials of B. hominis infection have so far been lacking. In spite of this, several drugs have been reported to be active against the parasite.6-8 The present study was carried out in order to evaluate the efficacy of metronidazole treatment in inducing clinical remission and parasitologic eradication in immunocompetent individuals with B. hominis as the only evident cause of diarrhea.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Animals
  • Antiprotozoal Agents / administration & dosage
  • Antiprotozoal Agents / therapeutic use*
  • Blastocystis Infections / drug therapy*
  • Blastocystis Infections / epidemiology*
  • Blastocystis Infections / etiology
  • Blastocystis Infections / parasitology
  • Blastocystis hominis / isolation & purification*
  • Diarrhea / drug therapy*
  • Diarrhea / epidemiology*
  • Diarrhea / etiology
  • Diarrhea / parasitology
  • Drug Administration Schedule
  • Enzyme-Linked Immunosorbent Assay
  • Feces / parasitology
  • Female
  • Humans
  • Italy / epidemiology
  • Male
  • Metronidazole / administration & dosage
  • Metronidazole / therapeutic use*
  • Middle Aged
  • Single-Blind Method
  • Treatment Outcome


  • Antiprotozoal Agents
  • Metronidazole