Prevalence and clinical spectrum of chronic viral hepatitis in a middle-aged Swedish general urban population

Background: Although abundant data are available regarding the prevalence o f chronic hepatitis B or C virus (HBV, HCV) among both blood donors and pat ients with liver diseases, corresponding data for the general population ar e scarce. Accordingly, this study was designed to investigate the prevalenc e and clinical spectrum of HBV and HCV in a general Swedish middle-aged urb an population. Methods: Demographic data and blood samples were collected f rom subjects enrolled in a prospective study of cancer development in the c ity of Malmo (population 250,000). The participation rate in the preliminar y examination was 46.2%. From 12,445 individuals born between 1926 and 1945 and included in the study, a statistically representative subsample of 610 3 persons was selected. Blood samples were available from 5533 of these. Th e mean age of the subjects in the series was 58.5 +/- 5.9 years, and 59% we re women. The HBV markers used were anti-HBc and HBsAg. HCV antibodies were detected with a third generation anti-HCV ELISA, followed by immunoblottin g (RIBA 3) if the test was positive. Immunoblot-reactive samples were analy sed for HCV-RNA by polymerase chain reaction and genotyped. In all patients with signs of chronic HBV or HCV, epidemiological data were evaluated and liver biopsies obtained. Results: Of the series as a whole (n = 5533), 4.2% (n = 211) tested positive for anti-HBc and 0.2% (n = 10) for HBsAg. RIBA 3 analysis showed 0.37% (18/5533) to be anti-HCV-positive, of whom 83% (15/1 8) were HCV-RNA-positive. Apart from two (both from HBsAg carriers) with no rmal histology, all liver biopsies manifested various degrees of inflammati on and fibrosis. Among anti-HCV-positives, median grade was 6 and median st age 1 (Knodell score). Conclusion: The prevalence of both chronic HBV and H CV is low in the Swedish general urban middle-aged population. Nonetheless, the long-term effects on the population and the health care system may be significant.