Hepatitis B - Emergency Medicine handbook
Overview
- Hepatitis B virus (HBV) is a partially double‑stranded DNA hepadnavirus transmitted by exposure to infected blood and body fluids: percutaneous (needlestick, injecting drug use), sexual contact and perinatal (mother → child). Household spread is possible but less efficient.
- Incubation period commonly 40-160 days (often 60-90 days). (Green Book; NICE CG165)
- Acute illness ranges from asymptomatic infection to cholestatic hepatitis with fever, malaise, anorexia, right‑upper‑quadrant discomfort, jaundice and dark urine.
- Outcomes: most adults clear acute infection; about 5-10% develop chronic infection. Complications include fulminant hepatic failure (~1%), cirrhosis, hepatocellular carcinoma and immune‑complex extrahepatic disease (e.g., glomerulonephritis, polyarteritis nodosa). (Green Book; NICE)
Key clinical features to recognise in the ED
- Systemic prodrome: fever, myalgia, anorexia, nausea and vomiting.
- Hepatic: jaundice, pruritus, pale stools, right‑upper‑quadrant pain.
- Severe disease signs: hepatic encephalopathy, coagulopathy, hypotension or multi‑organ dysfunction - consider acute liver failure and urgent transfer.
Serology - what to request and how to interpret
- Minimum tests in suspected acute HBV: HBsAg and anti‑HBc IgM. Also request liver function tests (LFTs) and INR.
- Additional tests for ED or baseline specialist workup: anti‑HBs (immunity), HBeAg and HBV DNA (infectivity/viral load), tests for other causes of hepatitis (HAV, HCV, EBV, CMV) and pregnancy test when relevant.