The prevalence of isolated hepatitis B core antibody and its related risk factors among male injected drug users in Isfahan prisons

The prevalence of isolated hepatitis B core antibody (anti‑HBc) varies between 1% and 30% in different populations. Isolated anti‑HBc‑positive patients who suffer from occult hepatitis B virus (HBV) infection have the potential to transmit HBV infection. So isolated anti‑HBc screening is a valuable tool to prevent HBV transmission. Considering the importance of isolated anti‑HBc screening and high prevalence of HBV among injected drug users (IDU) prisoners, we designed this study to evaluate the isolated anti‑HBc positivity among inmates with the history of IDU in our area.

We did this cross‑sectional study from September 2009 to March 2010 among volunteer male IDU prisoners in Isfahan. Blood samples were taken from all of subjects and tested for HBV markers. Then a questionnaire containing socio‑demographic, drug histories and high risk behaviors information was completed for all participants. Data analysis was done utilizing univariate analysis and multiple logistic regressions. A P < 0.05 was considered significant.

Totally 970 male IDU prisoners (mean age 32.6 ± 8.1) were included in our study. The prevalence of isolated HBc Ab was 4.5%. Isolated anti‑HBc significantly was related to tooth filling (OR: 2.62, CI: 1.20‑7.14) and imprisonment (OR: 3.95, CI: 1.39‑11.18). We couldn’t find any relationship between isolated anti‑HBc positivity and addiction duration, incarceration frequency, recent incarceration duration or number of injection per month.

For screening high risk groups in parallel with hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb) and other viral markers, maybe it is better to check HBcAb too, because isolated HBcAb‑positive patients may have occult hepatitis B infection which could transfer the infection to others.