title: Blastocystis hominis infection in a post-cardiotomy patient on extracorporeal membrane oxygenation support: A case report and literature review.
abstract: BACKGROUND
  Opportunistic pathogens can cause severe damage leading to irreversible complications in immune-compromised patients. Here we describe a patient who sustained Blastocystis hominis infection resulting in severe sepsis while on extracorporeal membrane oxygenation (ECMO) support, and the course of treatment taken to treat him.
  
  
  METHODS
  Our case, a 34-year-old Filipino man, was hospitalized for valvular disease and received valve replacements. ECMO and an intra-aortic balloon pump (IABP) were implemented when the patient developed progressive heart failure after cardiac surgery. Unfortunately, the patient suffered from sepsis with persistent fever and diarrhea, and subsequent examinations indicated the patient was infected by B. hominis. After adequate administration of the antibiotic metronidazole, the patient's symptoms subsided and he was discharged.
  
  
  CONCLUSIONS
  Blastocystis hominis is a unicellular protozoa commonly found in the intestinal tract, and the prevalence of B. hominis is 1.5-10% in developed countries and 30-50% in developing countries. The patient needed the support of ECMO and IABP, was immunocompromised to a certain extent; B. hominis can be a harmful opportunistic pathogen for them and lead to severe irreversible complications such as death.
  
  
  CONCLUSIONS
  This is the first published article showing that the opportunistic pathogen, B. hominis, can cause severe infection in patients on ECMO support, a result that should be kept in mind when patients come from a place with a high prevalence of B. hominis. The prophylactic medication should be administered routinely when patients live in the region and extracorporeal life-support is used.
authors.affiliation: Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Chih-Hsuan
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Hsin-Yun
authors.initials: HY
authors.lastname: Sun
authors.affiliation: Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Hsiung-Fei
authors.initials: HF
authors.lastname: Chien
authors.affiliation: Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Hong-Shiee
authors.initials: HS
authors.lastname: Lai
authors.affiliation: Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. Electronic address: nickchou@ntu.edu.tw.
authors.forename: Nai-Kuan
authors.initials: NK
authors.lastname: Chou
keywords: Blastocystis hominis; Extracorporeal membrane oxygenation