[Hepatitis C virus infections among persons attending special clinics dealing with problems related to social conditions].

We have studied the prevalence of hepatitis C virus antibodies among 526 persons who attended an HIV diagnostic and counselling clinic and a clinic for sexually transmitted diseases in Oslo, Norway, during a 4-month period in early 1990. Possible risk factors for contracting hepatitis C virus infection were analysed and compared with results of the anti-hepatitis C virus test. The over-all prevalence rate of positive anti-hepatitis C virus tests was 7%. The prevalence rate was highest, 70%, among intravenous drug users (26/37). When intravenous drug users were excluded, only 2% of the remaining 484 persons had antibodies to hepatitis C virus. Among persons with no history of intravenous drug use, a positive correlation was found among women between the presence of hepatitis C virus antibodies and previous gonorrhoea. Male homosexual activity did not correlate with the presence of hepatitis C virus infection. Neither the number of heterosexual partners, nor sex with intravenous drug users, correlated with the presence of hepatitis C virus antibodies. Thus, according to our study the overwhelming risk factor for contracting hepatitis C virus infection was intravenous drug use.