title: No evidence for patient-to-patient transmission of hepatitis C virus during upper gastrointestinal endoscopy: molecular studies on three acute hepatitis C patients.
abstract: BACKGROUND
  The risk of patient-to-patient transmission of hepatitis C virus (HCV) during endoscopy remains controversial. Using molecular approaches, we examined the possibility of patient-to-patient transmission of HCV in three patients who developed acute hepatitis C 1-6 months after examination by upper gastrointestinal endoscopy (UGIE) in a hospital endoscopy unit in Japan.
  
  
  METHODS
  For the source of HCV infection, we used frozen sera obtained from potential candidates who underwent UGIE earlier than three index patients on the same days in the same unit. HCV genotype was determined by multiplex polymerase chain reaction (PCR) with genotype-specific primers. The 1087-nucleotide (nt) sequence of the NS5B region of the HCV genome was compared between index patients and their HCV-viremic candidates.
  
  
  RESULTS
  The three index patients were exclusively infected with HCV of genotype 1b. Among a total of 60 candidate patients who underwent UGIE earlier than the index patients, 14 were positive for anti-HCV, of whom 12 had detectable HCV-RNA (1b, n = 9; 2a, n = 1; 2b, n = 2) on sera collected during each UGIE. Shared identity within the 1087-nt NS5B sequence was less than 95.0% between index patients and HCV/1b-infected candidates (n = 3, 1 and 5, respectively). None of the remaining 46 candidates who were negative for anti-HCV at UGIE examination tested positive for HCV-RNA, nor seroconverted to anti-HCV on their sera, which most likely excludes the possibility of HCV viremia despite the anti-HCV-negative serology at UGIE examination.
  
  
  CONCLUSIONS
  The present study suggests that patient-to-patient transmission of HCV during UGIE is infrequent.
authors.affiliation: Department of Health Science of Working Life and Environment, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan. tak-toda@mediacat.ne.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Toda
authors.forename: Takehiro
authors.initials: T
authors.lastname: Mitsui
authors.forename: Yukie
authors.initials: Y
authors.lastname: Tsukamoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ebara
authors.forename: Kazuo
authors.initials: K
authors.lastname: Masuko
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takahashi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okamoto
mesh_terms: D000368:Aged; D003428:Cross Infection / Q000209:etiology / Q000635:transmission*; D018562:Disease Transmission, Infectious; D016145:Endoscopy, Digestive System / Q000009:adverse effects*; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D006526:Hepatitis C / Q000209:etiology / Q000635:transmission*; D006801:Humans; D008297:Male; D008875:Middle Aged