Confirmation of nosocomial hepatitis C virus infection in a hemodialysis unit.

OBJECTIVES: To investigate a hepatitis C virus (HCV) outbreak in a hemodialysis unit and determine the source of transmission. METHODS: We have prospectively investigated the epidemiology of hemodialysis-related HCV infection in a single unit since 1989. In September 2000, acute hepatitis C (AH-C) was diagnosed in 5 patients by alanine aminotransferase elevation and HCV genotype 1b viremia without antibody to HCV. We surveyed the epidemiologic situation and performed polymerase chain reaction sequence analysis of the HCV 5'-noncoding (5'NC) region in the patients for comparison with 9 patients with chronic HCV genotype 1b viremia. RESULTS: Sequence analysis of the 5'NC region showed the consistency in the 5 independent clones from each AH-C patient and those from each chronic HCV viremia patient and no quasispecies over time in the clones of any of 14 analyzed patients. All AH-C patients had the same sequencing of the 6 variations in the region with the only other patient. A saline ampoule, used for heparin solution during hemodialysis, had a recap function. It was difficult to determine whether the ampoule was new or had already been used. The source-patient often underwent hemodialysis before the AH-C patients and most of their hemodialysis-related medicine was prepared during the source-patient's treatment. These findings suggested a high possibility that the AH-C patients shared a single heparin-saline solution ampoule contaminated by HCV from the source-patient. CONCLUSION: Nosocomial HCV infection occurred as a result of poor infection control practice when a patient with chronic HCV viremia received treatment prior to other hemodialysis patients.