Patient-to-patient transmission of hepatitis C virus (HCV) during colonoscopy diagnosis

Abstract

BackgroundNo recognized risk factors can be identified in 10-40% of hepatitis C virus (HCV)-infected patients suggesting that the modes of transmission involved could be underestimated or unidentified. Invasive diagnostic procedures, such as endoscopy, have been considered as a potential HCV transmission route; although the actual extent of transmission in endoscopy procedures remains controversial. Most reported HCV outbreaks related to nosocomial acquisition have been attributed to unsafe injection practices and use of multi-dose vials. Only a few cases of likely patient-to-patient HCV transmission via a contaminated colonoscope have been reported to date. Nosocomial HCV infection may have important medical and legal implications and, therefore, possible transmission routes should be investigated. In this study, a case of nosocomial transmission of HCV from a common source to two patients who underwent colonoscopy in an endoscopy unit is reported.ResultsA retrospective epidemiological search after detection of index cases revealed several potentially infective procedures: sample blood collection, use of a peripheral catheter, anesthesia and colonoscopy procedures. The epidemiological investigation showed breaches in colonoscope reprocessing and deficiencies in the recording of valuable tracing data. Direct sequences from the NS5B region were obtained to determine the extent of the outbreak and cloned sequences from the E1-E2 region were used to establish the relationships among intrapatient viral populations. Phylogenetic analyses of individual sequences from viral populations infecting the three patients involved in the outbreak confirmed the patient pointed out by the epidemiological search as the source of the outbreak. Furthermore, the sequential order in which the patients underwent colonoscopy correlates with viral genetic variability estimates.ConclusionsPatient-to-patient transmission of HCV could be demonstrated although the precise route of transmission remained unclear. Viral genetic variability is proposed as a useful tool for tracing HCV transmission, especially in recent transmissions.

Patient-to-Patient Transmission of Hepatitis C at Iranian Thalassemia Centers Shown by Genetic Characterization of Viral Strains

“…Nosocomial transmission of hepatitis C has previously been described between patients and at different hospital settings outside Iran (8, 16-21). However, phylogenetic analysis of the HCV strains was performed only in few of the studies to identify common source of infection or route of transmission (8, 18, 19). Until now, nosocomial HCV transmission based on sequencing and phylogenetic analysis of patient HCV strains at thalassemia centers has not previously been reported.…”

Hepatitis C virus transmission during colonoscopy evidenced by phylogenetic analysis

“…This is in line with previous reports on patient-to-patient HCV transmission events associated with a colonoscopy procedure. 6,9 In contrast, several studies have strongly associated unsafe injection practices during the anesthetic procedure with HCV transmission in endoscopy units. 7,8,10 The case described here highlights the importance of strictly following standard precautions by healthcare workers in order to prevent HCV transmission events through unsafe medical practices.…”

“…[3][4][5] Transmission during colonoscopy procedures has also been reported. [6][7][8][9][10] However, the direct transmission by the use of a contaminated colonoscope remains controversial and might be underestimated.…”

Outbreak Column 9: Endoscopy-related outbreaks

“…Bloodborne virus cross-transmission via an endoscope has been reported (Gonzalez-Candelas et al, 2010). However, outbreak investigators must remain open minded when the outbreak pathogen is a bloodborne virus.…”