Introduction to hepatitis B
An overview of viral hepatitis, including a table comparing the clinical features of hepatitis A, B, C, D and E, is provided here.
Hepatitis B virus (HBV) is transmitted through infected body fluids (eg blood, sexual fluids, mother-to-child transmission). The likelihood that hepatitis B infection becomes chronic is related to the age at which a person becomes infected. Ninety-five percent of immunocompetent adults acutely infected with hepatitis B clear the virus and become hepatitis B surface antigen (HBsAg) negative and hepatitis B surface antibody (anti-HBs) positive within 6 months; less than 1% develop acute liver failure. In contrast, most infants and young children infected with hepatitis B progress to chronic infection. Chronic hepatitis B is defined as persistent detection of HBsAg for longer than 6 months. The phases of chronic hepatitis B infection are shown in Phases of chronic hepatitis B infection. Patients can transition through the defined phases in different ways, making chronic hepatitis B a complex and dynamic disease.
It is estimated that over 220 000 Australians have chronic hepatitis B infection, the majority of whom are migrants from regions with a high prevalence of hepatitis B (eg Asia, Africa, Mediterranean countries, Pacific Island nations) or Aboriginal or Torres Strait Islander people. Most people with chronic hepatitis B in Australia acquired the infection at birth (via mother-to-child transmission) or in early childhood.
Improving access to testing and treatment for chronic hepatitis B in Australia is essential. It is estimated that one-third of people with hepatitis B in Australia remain undiagnosed, and approximately three-quarters of those eligible for antiviral therapy are not receiving it.
Enhanced testing and treatment of hepatitis B in the community is a crucial step towards reaching national testing and treatment targets, and the World Health Organization (WHO) viral hepatitis elimination goals. Treatment can be initiated by a relevant specialist, or a medical practitioner or nurse practitioner who is an accredited prescriber1. Medical practitioners who are not accredited can perform hepatitis B testing and arrange for referral of patients with chronic hepatitis B to local specialist services. Information about management of hepatitis B in primary care is available on the B Positive website.
For more information on the management of hepatitis B infection, see the Australian consensus recommendations for the management of hepatitis B infection, available online.