Prevalence and risk factors of hepatitis B infection in injection drug users, Tehran (2001-2002)

Background and Aims: Hepatitis 8 virus (HBV) infection has a high incidence among injection drug users (IDUs). Several important behavioral risk factors influence transmission of HBV in this group. However, consensus has not been achieved on many of them. The aim of this investigation was to assess the prevalence and risk factors for HBV in IDUs. Methods: This cross-sectional study was carried out between 2001 and 2002 in Tehran. IDUs included people who, were being treated for drug abuse and those in the prison. Physician-completed risk factor questionnaires and blood samples (5 ml) for serologic HBV markers (ELISA) were used. Risk factors were evaluated in binary logistic regression (LR) model (forward) procedure for possible association with odds of past or current HBV infection. The evaluated risk factors were age, gender, sexual behavior, shared syringe use, duration of addiction, imprisonment, tattooing, past history of surgery, dental procedures, blood transfusion, jaundice, type of illicit drug use and level of education. Results: This study sample was comprised of 518 IDUs (89.6% males), including 386 (74.5%) prisoners. Antibody against HBV core antigen (HBcAb) was detected in 61.2% (n=317). The prevalence of hepatitis B surface antigen (HBsAg) was 3.7% (n=19). Among HBsAg positive patients, HBeAg was positive in 12 individuals (63.2%). In comparison with seronegative IDUs for HBcAb and/or HBsAg, the odds of using shared syringes, male sex and past history of bisexual relationship were 1.5 (P<0.05), 1.9 (P<0.05) and 2.4 (P<0.01), respectively. Conclusions: These results suggest that seroprevalence of hepatitis B is high but chronic carrier state is not frequent in IDUs. Imprisonment, male sex and having past history of bisexual relationship are independent risk factors for past or current hepatitis B infection.