Gastrointestinal













Acute viral hepatitis
Signs and symptoms
  • Fatigue, malaise, fever and jaundice
  • May be asymptomatic
  • Signs: tender hepatomegaly

Investigation
  • LFT: ALT > 10 x normal limit, AST > ALT (in the first 24-48 hours), direct hyperbilirubinaemia
  • Viral hepatitis serology
    • HAV: anti HAV-IgM
    • HBV: HBsAg, anti-HBc-IgM
    • HCV: HCV RNA

Management
  • Symptoms management + supportive care
    • F/U LFT in 1-2 weeks
    • Dietary advice: avoid high-carb diet (may induce fatty liver disease), avoid fatty diet if abdominal pain persists
  • Admit if any of the following:
    • Severe symptoms: nausea/vomiting, encephalopathy
    • Bilirubin > 15-20 mg/dL
    • Prolonged hyperbilirubinaemia > 2 weeks
    • Prolonged PT with rapidly falling AST/ALT
    • Hypoglycaemia
    • Hepatocellular failure (drops in albumin, ascites)

Prevention

Pre-exposure prophylaxis for HAV

Pre-exposure prophylaxis for HAV
Age (years)VaccineDose
1-15Havrix 3603 (0, 1, and 6 months)
16-18Havrix 7202 (0 and 6-12 months)
19 and aboveHavrix 14402 (0 and 6-12 months)

Post-exposure prophylaxis for HAV

  • Indications
    • Household or sexual contacts with infected individuals
    • Contacts in a childcare centre during outbreaks
    • Food handlers working in an establishment with infected individual(s)
  • Management
    • HAV Ig 0.02 mL/kg IM single dose (within 2 weeks of contact: 80-90% effective)
    • HAV vaccine (if unvaccinated, same dosing as for pre-exposure prophylaxis)

Pre-exposure prophylaxis for HBV

ENGERIX-B regimen
Age (years)VaccineDose
< 20ENGERIX-B (10 µg/0.5mL)3 (0, 1, 6 months)
20 or moreENGERIX-B (20 µg/1 mL)3 (0, 1, 6 months)

Alternatively,

EUVAX regimen
Age (years)VaccineDose
< 15EUVAX B (10 µg/0.5mL)3 (0, 1, 6 months)
15 or moreEUVAX B (20 µg/1 mL)3 (0, 1, 6 months)

Post-exposure prophylaxis for HBV

  • Indications
    • Percutaneous inoculation or transmucosal exposure to HBsAg-positive body fluid (e.g., needle stick injury)
    • Direct exposure following sexual contact

    • Serological Pattern of Acute HBV Infection (credit: who.int)

  • Management
    • HBV Ig 0.06 mL/kg IM (ASAP if needlestick, within 14 days if sexual contact)
    • Complete HBV vaccination (if unvaccinated, dosing as with pre-exposure)

Chronic Hepatitis B
Disease Progression
  • Immune tolerance phase: ALT normal, HBeAg +ve, HBV DNA high
  • Immune clearance phase: acute hepatitis, abnormal LFT, may lead to hepatic decompensation
  • Residual phase: HBe seroconversion (HBeAg -ve but anti-HBe +ve) + liver function may be normal

Investigation
  • HBsAg positive > 6 months

Acute Hepatitis B Serological Profile
Acute PhaseSerology Profile
EarlyHBsAg +ve, anti-HBc +ve
WindowIgM anti-HBc +ve
Recovered (if applicable)IgG anti-HBc +ve, anti-HBs +ve

Chronic Hepatitis B Serological Profile
Chronic PhaseSerology Profile
High InfectivityHBsAg +ve, HBeAg +ve, HBV-DNA high
Low InfectivityHBsAg +ve, HBeAg -ve, anti-HBe +ve, HBV-DNA low
Precore mutation individualsHBsAg +ve, HBeAg -ve, HBC-DNA high

Serological Pattern of Chronic HBV Infection (credit: who.int)

Management

Management of Hepatitis B (credit: Survival for All vol.1)

References:

  • Survival for all volume 1
  • WHO: Training workshop on screening, diagnosis and treatment of hepatitis B