PREVALENCE AND DETERMINANTS OF ANTI-HCV SEROPOSITIVITY AND OF HCV GENOTYPE AMONG INTRAVENOUS-DRUG-USERS IN BERLIN

A cross-sectional study was carried out to identify risk factors for s eropositivity for antibodies against hepatitis C virus (HCV) and to as sess the distribution and determinants of HCV genotypes among intraven ous drug users (IVDUs). The study population consisted of 405 IVDUs. S erum specimens were tested for seromarkers for HCV, for human immunode ficiency virus (HIV), for hepatitis B virus (HBV) and for syphilis. HC V RNA determination by polymerase chain reaction (PCR) and virus typin g were performed in a subsample of anti-HCV-positive specimens (n = 13 5). Of the IVDUs, 83% were anti-HCV-positive, 18% HIV-infected, and 58 % HBV (anti-HBc)-positive. Longer duration of intravenous drug use, sy ringe sharing in prison, and higher number of IDVU sex partners were i ndependent risk factors for anti-HCV positivity. HCV RNA was detected in 76% of anti-HCV-positive IVDUs. HCV genotypes 1 (49%) and 3 (44%) w ere most commonly found. All the type 3 isolates were identified as su btype 3a, and 95% of the type 1 isolates as subtype 1b. In logistic re gression analysis, HCV type 3a viraemia was significantly associated w ith lack of HIV infection and a higher number of sex partners. The res ults indicate that preventive measures are needed to reduce syringe sh aring among IVDUs in prisons. Sexual contacts with other IVDUs may pla y a role in the HCV epidemic among IVDUs, In Germany, HCV type 3a infe ction appears to be much more common among IVDUs than among other HCV risk groups such as transfusion recipients or haemophiliacs.