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 data completeness and on epidemiological assessment of affected populations.

Methods: Notified cases of non-acute hepatitis B and C were analysed to determine demographic 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 time doctors were contacted for information about new diagnoses.

Results: During the enhanced period, completeness for country of birth and Indigenous status doubled for both hepatitis B and hepatitis C, from 18–37% to 48–65%. The incidence ratio of hepatitis 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 to other countries increased. New data fields identified that 12% of hepatitis C diagnoses occurred in a correctional facility, and 2% of hepatitis B cases were healthcare workers.

Conclusions: Improved data completeness highlighted the underlying epidemiology of chronic viral hepatitis, demonstrating the increased burden of infection among specific priority populations.

Implications for public health: Enhanced surveillance provides greater insight into the epidemiology of chronic viral hepatitis, identifying groups at risk and opportunities for public health action.