Background and aim: This retrospective study examined the prevalence of co-infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) and the frequency of chronic hepatitis in HIV-infected patients with respect to both the different risk groups and the serological results.
Patients and methods: All Zurich participants of the Swiss HIV Cohort Study were evaluated who had available results of hepatitis B and C serology and ALT.
Results: Of the total 279 patients, 52% belonged to the intravenous drug user, 34% to the homosexual, and 11% to the heterosexual risk category. Serologically, previously acquired infection with HBV alone could be demonstrated in 92 (33%), HCV alone in 9 (3%), and both HBV and HCV in 130 (47%) patients. Only 3% of patients with sexually acquired HIV infection had anti-HCV antibodies, whereas co-infection with HBV and HCV was present in 87% of intravenous drug users. Among the 222 patients with previous HBV contact, 25 (11%) had positive HBsAg and 91 (41%) had "anti-HBc alone", both assumed to represent active HBV infection. 66 (24%) of 279 patients had chronic hepatitis with ALT elevation lasting > or = 6 months. Chronic hepatitis was present in 46% of those with active HBV and HCV co-infection, in 36% of those with HCV infection alone and in 18% of those with active HBV infection alone (P < 0.001). Of the 66 cases of chronic hepatitis, 58 were associated with HCV infection, and only 2 cases had no serological signs of active HBV or HCV infection.
Conclusion: In patients with sexually acquired HIV infection, HBV had frequently been co-transmitted. In contrast, almost all of those infected by means of intravenous drug use had a co-infection with both HBV and HCV. The latter seems to play the strongest role in the development of chronic hepatitis with persistent ALT elevation. A chronic ALT elevation was almost always associated with serologically active HBV or HCV infection.