	Headline
Etiology	dsDNA hepadna virus Co-infection with Hep D can increase chance of fulminant hepatic failure 5% of acute infection develops into chronic infection
Pathogenesis	Immune-mediated damage to liver - bystander damage from T cell derived cytokines and antibody-dependent cell-mediated cytotoxicity
Epidemiology	perinatal, sexual, parenteral, haemodialysis/transfusion (rare in UK); 10-15% carriage in some parts of world. 0.1-2% prevalence in UK?
Clinical presentation	Incubation: 6-20 weeks/quoted as 6 weeks to 6 months Prodrome - nonspecific Acute hepatitis - insidious development
Investigations	acute infection: HBsAg, anti-HBc IgM chronic: HBsAg > 6 months exposure (previous infection): anti-Hbc IgG immunity: anti-HBs See Hepatitis B serology
Management	antivirals if severe (signs of decompensated liver disease) - entacavir, tenofovir liver transplant

immunisation

Contains HBsAg adsorbed onto aluminium hydroxide adjuvant and is prepared from yeast cells using recombinant DNA technology
3 doses (0, 1, 2 months most common) + one off booster 5 years later
10-15% are poor responders
considered safe in pregnancy/no evidence of harm

higher risk groups

CKD 4-5, end stage renal disease on haemodialysis
solid organ transplant recipients
people receiving regular blood product transfusions
healthcare workers
intravenous drug users
sex workers
close family contacts of an individual with hepatitis B
People participating in contact sports.
People travelling for: relief aid work, medical care, areas of high/medium prevalence