Markers of hepatitis B infection and immunity in patients attending Aboriginal community controlled health services.

Objective: Hepatitis B virus (HBV) infection remains an important cause of morbidity and mortality in Aboriginal and Torres Strait Islander people, who have high rates of infection compared with non-Indigenous Australians. We aimed to increase the evidence base around HBV in Aboriginal and Torres Strait Islander people through an analysis of routine clinical encounter data. Design: A cross-sectional study of de-identified records from electronic patient systems over 5 years (8 January 2009 to 11 July 2013). Setting: Four Aboriginal community controlled health services. Participants: All patients attending for a clinical visit were included in the study. Hepatitis B testing records were included if at least one serological test for HBV was done. Main outcome measures: Percentage of clinical patients tested for hepatitis B, compliance with guidelines and serological status. Results: A total of 2959 people aged 15–54 years were screened for HBV, representing 17.2% of all people with a clinical visit in the study period. A total of 865 Aboriginal patients were tested concurrently for hepatitis B surface antigen (HBsAg), hepatitis B core antibody and hepatitis B surface antibody. Of those, 352 (40.7%) were susceptible to HBV infection (95% CI, 37.4%–43.9%) and 34 (3.9%) had either an acute or chronic infection indicated by a positive HBsAg result (95% CI, 2.6%–5.2%). In 329 women with antenatal screening, six (1.8%) returned a positive HBsAg result (95% CI, 0.37%–3.28%). Conclusion: A substantial proportion of patients tested were susceptible to HBV, with a high percentage potentially infectious compared with the general population. High levels of active infection and susceptibility to infection suggest many opportunities for transmission and indicate the potential benefit of routine HBV testing and vaccination in this population.