title: Hepatitis C virus transmission during colonoscopy evidenced by phylogenetic analysis.
abstract: BACKGROUND
  Nosocomial transmission events still play an important role in hepatitis C virus (HCV) spreading. Among most reported medical procedures involved in nosocomial transmission, endoscopy procedures remain controversial and might be underestimated.
  
  
  OBJECTIVE
  The aim of the study was to investigate a case of nosocomial person-to-person transmission of HCV in an endoscopy unit.
  
  
  METHODS
  An acute HCV infection was detected in a person that had undergone a colonoscopy after an HCV-infected patient. Serum samples from both persons were subjected to a molecular epidemiology study. The HCV NS5B genetic region was amplified and directly sequenced and the E1-E2 region was amplified, cloned and sequenced (20 clones per specimen). All sequences were subjected to phylogenetic analyses. A conventional epidemiological investigation was performed to determine the most likely cause of HCV transmission.
  
  
  RESULTS
  NS5B sequence analysis revealed that both persons were infected with closely related HCV-1b strains. Furthermore, phylogenetic analysis of E1-E2 sequences evidenced a direct transmission between patients. The epidemiological investigation pointed out to anesthetic procedures as the most likely source of HCV transmission. The index case, not having spontaneously cleared the infection 10 months after infection, required antiviral treatment, which resulted in a sustained virological response.
  
  
  CONCLUSIONS
  The molecular epidemiology study performed provided evidence of a person-to-person transmission of HCV during a colonoscopy procedure, and the anesthetic procedure was the most likely source of HCV transmission. This study highlights the importance of strictly following standard precautions by healthcare workers in order to prevent nosocomial HCV transmission.
authors.affiliation: Microbiology Service, Fundació Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain.
authors.forename: Verónica
authors.initials: V
authors.lastname: Saludes
authors.forename: María
authors.initials: M
authors.lastname: Esteve
authors.forename: Irma
authors.initials: I
authors.lastname: Casas
authors.forename: Vicente
authors.initials: V
authors.lastname: Ausina
authors.forename: Elisa
authors.initials: E
authors.lastname: Martró
mesh_terms: D016000:Cluster Analysis; D003113:Colonoscopy / Q000009:adverse effects*; D003428:Cross Infection / Q000635:transmission*; D016174:Hepacivirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006526:Hepatitis C / Q000635:transmission*; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014759:Viral Envelope Proteins / Q000235:genetics; D017361:Viral Nonstructural Proteins / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase
chemical_list: D012367:RNA, Viral; D014759:Viral Envelope Proteins; D017361:Viral Nonstructural Proteins; C087035:E1 protein, Hepatitis C virus; C091015:glycoprotein E2, Hepatitis C virus; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase