PREVALENCE OF HEPATITIS-C GENOTYPES AMONG PATIENTS WITH CHRONIC HEPATITIS-C IN NORWAY

Among 116 patients with biopsy-confirmed chronic hepatitis C (Riba 2 o r Riba 3 positive) in a multicenter study in southern Norway on interf eron, we determined hepatitis C virus genotype by restriction fragment length polymorphism (RFLP) of the 5' NCR. The RFLP method was supplem ented by and compared with a serological typing method based on the de tection of type-specific antibody to peptide from the NS-4 region. A t otal of 102/106 (96%) patient sera showed detectable type-specific ant ibody to NS-4 peptides and corresponded in all cases, except two, to t he genotype detected by polymerase chain reaction. Combining the resul ts from RFLP genotyping and serotyping, genotype 1 was found in 40 (35 %) (27 with 1a and 10 with 1b, 3 subtypes not determined), genotype 2 in 15 (13%) (subtype 2b in 14 and 1 subtype not determined), and genot ype 3 in 58 (50%) of patients. The low mean age of the patients (34 ye ars), the low prevalence of cirrhosis (3.5%), the short duration of th e disease, and a high prevalence of intragenous-drug abusers map accou nt for the low prevalence of infection with genotype 1b (9%). The epid emiological features of hepatitis C patients are markedly different fr om patient groups described in southern Europe in terms of risk factor s, age, and genotype distribution.