Hepatitis C in the general adult population of Oslo: Prevalence and clinical spectrum

Background: The prevalence of hepatitis C (HCV) in Northern Europe has not been well described. This study aimed to estimate the prevalence and spectrum of hepatitis C infection in the general adult population of Oslo, Norway. Methods: The study was part of the Oslo Health Study 2000-2001 and included a random selection of individuals older than 30 years living in Oslo County. Sera from 11,456 participants were screened for anti-HCV (EIA-3), positive samples were confirmed (RIBA-3) and examined for HCV RNA (PCR). All anti-HCV positive patients were offered clinical evaluation. Routine biochemical liver tests were performed. Candidates for HCV treatment were asked to undergo a percutanous liver biopsy. Results: Among 11,456 participants HCV RNA was detected in 62 (0.5%) and HCV RNA with raised serum alanine aminotransferase (ALT) in 46 (0.4%). Anti-HCV was detected in 78 (0.7%) with a peak prevalence of 1.5% among subjects 40 and 45 years old. Being anti-HCV positive was associated with being unmarried, unemployed and having low education. Anti-HCV prevalence was higher among subjects with alcohol-related problems compared to those without (4.4% versus 0.6%, P < 0.001). It was also higher among smokers compared to non-smokers (2.0% versus 0.2%, P < 0.001). In 33 liver biopsies, bridging fibrosis was seen in 8 (24%) and cirrhosis in 1 (3%). The route of transmission was injecting drug use in 67%, transfusion in 6% and unknown in 27%. Conclusion: In this population-based survey the prevalence of chronic hepatitis C was 0.5% and ALT was raised in 80% of those with chronic infection.