The source of acute hepatitis B virus (HBV) infection in two women (55 and 72 years old) was investigated. They displayed no risk factors for acquiring HBV infection, other than treatment with local anaesthetic injections some months previously. The HBV strains were sequenced and showed distinct homology to strains seen in Swedish intravenous drug users (IVDU). Prior to these patients' acute infection, an outbreak of HBV had occurred among IVDU in the same county. Analysis of the HBV strains from six of these IVDUs showed their core promoter, precore and pre-S sequences (679 nucleotides) to be identical to those from the two patients. Cross-contamination between samples was excluded and the most likely source of infection was thought to be multiple-dose vials of local anaesthetic that had been contaminated with the HBV strain circulating among the IVDU population in the community. We believe that multiple-dose vials have no place in modern healthcare and recommend sequence homology analysis as an alternative or additional way to trace a source of HBV infection.
Copyright 1999 The Hospital Infection Society.