Hepatitis B virus (HBV), a double-stranded DNA virus.
|Asymptomatic infection: common|
|Acute hepatitis: lethargy, nausea, fever, anorexia for a few days then jaundice, pale stools and dark urine, incubation 45-180 days (mean: 60 days)|
|Chronic hepatitis: infection lasting over 6 months, can be life-long|
|Cirrhosis: ankle swelling, ascites, GI bleeding, encephalopathy, jaundice|
|Hepatocellular carcinoma: abdominal mass|
|AST, ALT||Blood||Raised in acute and chronic infection|
|HBsAg||Blood||Current hepatitis B infection|
|Anti-HBs||Blood||Immunity to hepatitis B infection|
|HBeAg||Blood||Associated with higher infectivity|
|Anti-HBe||Blood||Associated with lower infectivity|
|HBV DNA||Blood||Viral replication|
|AST – Aspartate aminotransferase
ALT – Alanine aminotransferase
HBsAg – Hepatitis B surface antigen
Anti-HBs – Hepatitis B surface antibody
Anti-HBc – Hepatitis B core antibody
HBeAg – Hepatitis B envelope antigen
Anti-HBe – Hepatitis B envelope antibody
HBV DNA – Hepatitis B DNA (i.e. viral load)
Patients of unknown status should always have 3 initial tests performed (HBsAg, Anti-HBs and Anti-HBc) to determine infection status and the need for vaccination. All 3 tests are Medicare rebateable simultaneously. Specify the above tests on the request form rather than ‘hepatitis B serology’ and/or include “? Chronic hepatitis B” in the clinical notes section.
The National Hepatitis B Testing Policy provides more detail.
|Acute hepatitis: HBsAg positive, unwell, raised LFTs||Possible acute hepatitis B, needs supportive care, hospital admission if unwell or deteriorates|
|Chronic hepatitis: HBsAg positive for >6 months||Needs further investigation and possible treatment with antiviral agents and specialist review/management|
|Cirrhosis: ankle swelling, ascites, gastrointestingal bleeding, encephalopathy, jaundice||
Specialist review if suspected. All patients with cirrhosis require treatment with antiviral therapy.
Treatment is available from specialist services and suitably trained GPs. It will generally consist of oral antiviral therapy which is taken on a long-term basis. Less commonly, pegylated interferon is used.
Consider seeking specialist advice before treating any complicated presentation.
|Pregnant women||Needs specialist review. Infant needs hepatitis B vaccination and immunoglobulin (HBIG) at birth, mother may need antiviral therapy to reduce transmission at birth.|
Treatment is available from specialist services and suitably trained GPs.
See Australasian Contract Tracing Manual - Hepatitis B for more information.
Prior infection and clearance provides lifelong immunity to re-infection. Patients with resolved infection may experience a hepatitis B flare if immunocompromised (e.g. if receiving chemotherapy).