AN UNUSUAL STRAIN OF HEPATITIS-C VIRUS IN NEW-ZEALAND

Aims. To investigate the prevalence of hepatitis C virus (HCV) viraemi a in selected cohorts of New Zealand patients and to examine the strai ns of hepatitis C virus circulating in New Zealand. Methods. Hepatitis C viraemia was identified using a highly sensitive polymerase chain r eaction (PCR) assay to detect HCV ribonucleic acid (RNA). Selected vir us isolates were analysed for strain variation by restriction fragment length polymorphism (RFLP) of PCR products and two of the amplified p roducts were sequenced. Results. A high frequency of HCV viraemia was found in patients with a history of repeated exposures to blood or blo od products. RFLP analysis revealed the prevalence of an unusual strai n of hepatitis C which was further confirmed by sequencing. Identifica tion of the infecting hepatitis C strains resolved a suspected point s ource outbreak occurring in a maximum security prison. Conclusions. De tection bf circulating hepatitis C RNA is a sensitive and specific met hod for identifying active hepatitis C infection. Typing hepatitis C i solates has useful epidemiological application and facilitates the det ection of unusual HCV variants.