Establishment of a surveillance system (utilising Midwifes Data Collection Systems) for monitoring the impact of hepatitis B vaccination on the population prevalence of chronic hepatitis B virus infection in Australia

Objective: To examine how routine hepatitis B surface antigen (HBsAg) testing of antenatal women (as identified on the NT Midwifes Data Collection System) can be used to track the impact of hepatitis B (HBV) vaccination on the prevalence of chronic HBV infection in the Northern Territory (NT). Methods: Women who gave birth between 01 July 2002 and 30 June 2004 were identified from the NT Midwives Data Collection System (MDCS). For each woman, the unique hospital record number (HRN) was linked to the information system of the NT Government pathology service to obtain the results of serological tests for hepatitis B. The prevalence of HBsAg was calculated by age, Indigenous status, and maternal country of birth. Results: During the study period, 1061 records of women from the NT MDCS could be linked to HBsAg results. Overall, 33 (3.1%) were positive for HBsAg, of whom 29 were recorded as Indigenous and the remaining four were born outside Australia. Conclusions: Linking data from the NT MDCS and HBsAg results from government pathology service is a feasible means to monitor the impact of HBV vaccination policy. Implications: Routine inclusion of HBsAg results in all state and territory midwives data collections should be pursued.