To define and compare the prevalence, risk factors and understanding of hepatitis C transmission among Aboriginal and non-Aboriginal young offenders.

Cross-sectional study of young offenders (aged 12–19 years; median age, 16.6 years) in custody or serving community orders with the New South Wales Department of Juvenile Justice who participated in a physical and mental health survey between March 2002 and December 2005, and who provided blood samples for analysis of biochemistry, bloodborne viruses and sexually transmitted infections.

Risk factors and prevalence of hepatitis C antibody positivity.

Of the 1042 young offenders studied, 709 provided blood samples, 179 (25%) of whom identified as Aboriginal. Aboriginal adolescents had more markers of social disadvantage and higher rates of hepatitis B (9.6% v 5.2%; P = 0.04) than non-Aboriginal young offenders. Hepatitis C rates were high in both groups (7.3% v 5.3%; P = 0.33). Risk factors for hepatitis C were the same in both groups, the most important being injecting drug use (OR, 19; P < 0.001) and prior use of heroin (OR, 15; P < 0.001). Current custodial sentence doubled the risk of hepatitis C. Knowledge of hepatitis C transmission was very poor in both groups, with over 50% not knowing how it is transmitted and fewer than 10% able to identify sharing needles as a risk.

Hepatitis C rates are extremely high in all young offenders, and interventions to halt its spread are urgently needed. Aboriginal adolescents, who are over-represented in this population, are particularly at risk.