Hepatitis B

• high prevalence/endemic in china, africa, india
• Globally:
  • causes 40% of liver failure deaths
  • causes 57% of HCC deaths
  • 644,000 deaths/annum
• Birmingham
  • 0.2-0.8% depending on trust
• transmission
  • peri-natal infection (~100% of carriage if infected as baby vs 50% as toddler vs 5% adult)
  • sexual contact (MSM)
  • IVDU
  • infected blood products/non sterile inhections (21mill new infections/yr)
  • poor sanitation/overcrowding

Transmission in england and Wales

• yearly 3000 HBV infections arise
• 7.5% progress to chronic infection (~200)
• plus net migration of ~6500 migrants with chronic HBV

• pegylated IFN alpha
• Antivirals:
  • tenofovir
  • entecavir

• RNA, blood borne
• identified 1986
• requires HBV to complete replication cycle
  • uses HBsAg to encapsulate genome and envelope proteins
• all HBsAg +ve pts should be testes for anti-Delta Ab
• more common in Meditteranean, aub-Aharan afrtica, middle east, northern south america
• Dx
  • +ve for anti-delta ntibody and Delta virus RNA
• Tx
  • PegIFN 
  • only effcetive in ~20%
• causes liver disease over time (cirrhosis/HCC)