Molecular epidemiology of an outbreak of HCV in a hemodialysis unit: Direct sequencing of HCV-HVR1 as an appropriate tool for phylogenetic analysis

Infection with hepatitis C virus (HCV) is still a serious problem in hemodi alysis patients, despite screening of blood products for anti-HCV antibodie s. The prevalence of HCV in HD patients is between 15% and 30% in Germany. We report the molecular epidemiology of an HCV outbreak in a hemodialysis u nit in 1997 is determined. HCV hypervariable region 1 (HVR1) was amplified from serum samples of 19 patients by polymerase chain reaction (PCR) and se quenced directly. In addition, HCV isolates from 3 of these 19 patients wer e cloned and sequenced. 14 newly infected patients and two patients, who ha d been infected for several years had very closely related HCV isolates. Un related HCV isolates as well as sequences obtained from an HCV outbreak in a plasmapheresis center were found in different, distantly related branches . These findings provide strong evidence for nosocomial transmission of the virus, despite following strict general hygiene precautions. The productio n of anti-HCV antibody was delayed significantly or seroconversion did not occur at all during the period of: observation in 8 out of 14 newly infecte d HCV RNA positive patients. Close-meshed reverse transcription-polymerase chain reaction (RT-PCR) analyses on apparently non infected patients within hemodialysis units and upon admission of new patients is strongly recommen ded for the early detection and prevention of outbreaks of HCV. J. Med. Vir ol, 60:152-158, 2000. (C) 2000 Wiley-Liss, Inc.