Hepatitis D virus in Victoria 2000-2009

Background: Hepatitis D virus (HDV) coinfection can adversely affect prognosis and complicate management of chronic hepatitis B. The epidemiology and clinical practices surrounding HDV in Australia are poorly understood, with no robust estimates of the burden of disease, and the extent of appropriate testing and clinical follow up is unknown. Aims: To determine the number of reported cases of HDV in Victoria, Australia between 2000-2009 and to explore screening practices in patients at risk of HDV infection over the same time period. Methods: Data regarding HDV diagnoses in Victoria for 2000-2009 were obtained from notifiable disease surveillance and public health laboratory testing records. Notifications data were analysed to determine risk factors and demographics of HDV diagnoses where available, and laboratory records used to determine screening practices and follow up testing. Results: Eighty-seven notifications for HDV were recorded between 2000 and 2009. The median age at diagnosis was 34 (interquartile range 27-44), and the majority of cases were men (77%) and born overseas (71.4% of those with country of birth reported). During the same period, 2314 Victorian residents were tested for HDV infection, with 110 (4.75%) found to be positive. Both the number of people testing positive and the number of tests conducted steadily increased between 2005 and 2009. Of those patients with positive HDV antibody results, less than half (44 patients, 40%) were subsequently evaluated for replicative infection by polymerase chain reaction. Conclusion: The number of people being tested for HDV has increased over the past decade; however, gaps in the appropriate follow-up of infected patients are apparent. Birth overseas has become an increasingly important risk factor in Victorian notifications, highlighting the need for routine testing of people living with chronic hepatitis B for HDV infection.