Changing serological status and low vaccination-induced protection rates against hepatitis B characterize chronic hepatitis C virus-infected injecting drug users in Greece: need for immunization policy.

Objective: To evaluate the serological status of hepatitis B virus infection among Greek injecting drug users with chronic hepatitis C virus infection; to correlate hepatitis B virus infection status with the possible time of infection and the principal genotype of hepatitis C virus infection.

Methods: Two hundred and thirty consecutive injecting drug users with chronic hepatitis C virus infection were evaluated for serological markers of hepatitis B virus infection. One hundred and three of them (44.8%) reported intravenous drug use beginning before 1992 (group A) and 127/230 (55.2%) after 1992 (group B). Statistical analysis of data was based on Student's t-test and chi analyses.

Results: Eighty-five of 103 patients from group A (82.5%) and 28/127 (22%) from group B had serological markers of previous hepatitis B virus infection (P<0.001). Eleven patients from group A (10.6%) and 78 (61.4%) from group B were seronegative for all hepatitis B virus markers (P<0.001). Only 3.8% (4/103) of group A patients and 16.5% (21/127) of group B had vaccination-induced protective antibody levels (anti-HBs) against hepatitis B (P=0.02). The majority of patients were infected with hepatitis C virus genotype-3 (64.7% from group A vs 56.7% from group B, P=0.42). The percentages of patients infected with genotype-1 were also comparable in both groups (15.5% from group A vs 30.8% from group B, P=0.09). A significantly higher percentage of group A patients were infected with genotype-4 (19.7%) than those in group B (4.9%, P=0.02).

Conclusion: The serological profile of hepatitis B virus infection among Greek hepatitis C virus-infected injecting drug users is changing. The proportion of successfully vaccinated hepatitis B virus injecting drug users, although significantly higher than the previous decades, is still relatively low. Vaccination policy in this high-risk group for viral hepatitis is urgently needed.