Epidemiology of chronic hepatitis B and C in Victoria, Australia: insights and impacts from enhanced surveillance

Objective: To assess the impact of an enhanced viral hepatitis surveillance program on datacompleteness and on epidemiological assessment of affected populations.Methods: Notified cases of non-acute hepatitis B and C were analysed to determinedemographic characteristics and risk factors during the period prior to July 2015–June 2016,and during enhanced surveillance of the period July 2016–June 2017, during which timedoctors were contacted for information about new diagnoses.Results: During the enhanced period, completeness for country of birth and Indigenous statusdoubled for both hepatitis B and hepatitis C, from 18–37% to 48–65%. The incidence ratio ofhepatitis C among Aboriginal and Torres Strait Islander people increased from eight-fold to 11.4-fold, and the proportion of hepatitis B cases reported as born in China and Vietnam relative toother countries increased. New data fields identified that 12% of hepatitis C diagnoses occurredin a correctional facility, and 2% of hepatitis B cases were healthcare workers.Conclusions: Improved data completeness highlighted the underlying epidemiology ofchronic viral hepatitis, demonstrating the increased burden of infection among specific prioritypopulations.Implications for public health: Enhanced surveillance provides greater insight into theepidemiology of chronic viral hepatitis, identifying groups at risk and opportunities for publichealth action.