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Hepatitis B

 

Definition of Hepatitis B

  • An infection of hepatocytes by the hepatitis B virus

 

Epidemiology of Hepatitis B

  • Incidence low in UK and USA: about 0.5%.
    • High in Africa, Middle East, Far East: about  10-15%
  • Blood, sexual and vertical transmission
  • 350 million chronic carriers worldwide

 

Cause of Hepatitis B

  • Hepatitis B virus: a DNA virus with reverse transcriptase activity

 

Presentations of Hepatitis B

  • Often subclinical or flu-like illness
  • Acute presentation (if symptoms noted at all)
    • Jaundice (only 30-50%)
      • Dark urine/pale stools due to intrahepatic cholestasis (if jaundice severe enough)
    •  Serum-sickness-like syndrome (occasionally)
      • Rash, polyarthritis, fever
    • Arthritis or immune-complex-mediated renal failure (rarely)
    • Tender hepatomegaly
  • Chronic

 

 

Differential diagnosis of Hepatitis B

  • Other causes of acute hepatitis
    • Drugs, Hep A, Infection, alcohol
  • Other causes of chronic liver disease (see chronic liver disease page)

 

Staging of and interpreting viral markers of Hepatitis B (serology)

 

Video on interpreting viral serology in hepatitis B

Initial management of acute Hepatitis B

  • Blood tests:
    • FBC
    • LFTs
    • Clotting screen
    • Viral screen including HBsAg, HBV DNA, HBeAg, HIV, HCV, Hepatitis Delta
    • Autoimmune screen
  • Ultrasound liver
  • Treatment is discussed further below but is not normally undertaken in the acute phase other than supportive measures and alcohol avoidance.

 

Further management of chronic Hepatitis B

  • Investigate as per other causes of chronic liver disease (see CLD page)
  • HBV vaccine is available
  • Treatment
    • HBV is not yet curable and treatment aims for viral load suppression and to prevent liver cirrhosis and its complications.
    • Decision to treat takes into account a number of factors including degree of fibrosis, HBV DNA levels, comorbidities, likelihood of treatment success.
  • Treatment options
    • Pegylated interferon
      • No resistance develops
      • Finite duration of therapy
      • Less well tolerated than nucleoside or nucleotide analogue due to side-effect profile
      • Only moderate antiviral activity
    • Nucleoside (Lamivudine, Entecavir) and Nucleotide (Tenofovir) analogues
      • Potent antiviral effects
      • Few side-effects
      • Risk of resistance with some drugs

 

Complications of Hepatitis B

 

Prognosis of Hepatitis B

  • Acutely, mortality 1%.
  • About 10% will become chronically infected, and will either be asymptomatic carriers (non-infective, no liver damage) or have chronic hepatitis (which leads to cirrhosis and is infective)

 

Click here for medical student OSCE and PACES questions about Hepatitis B

Common Hepatitis B exam questions for medical students, finals, OSCEs and MRCP PACES

Click here to download free teaching notes on hepatitis B: Hepatitis B

Perfect revision for medical students, finals, OSCEs and MRCP PACES