355.2 🩺 國考版

355.2.1 高頻考點

355.2.1.1 Hepatitis Transmission

  • HAV: fecal-oral
  • HBV: blood, sexual, perinatal
  • HCV: blood (IDU, transfusion pre-1992)
  • HDV: blood (with HBV)
  • HEV: fecal-oral

355.2.1.2 Chronic Progression Rates

  • HAV: never
  • HBV: 5% adult, 30% child, 90% perinatal
  • HCV: 75-85% (highest)
  • HDV: 80%+ with superinfection
  • HEV: rare (immunocompromised)

355.2.1.3 HBV Serology Patterns

  • Acute: HBsAg + anti-HBc IgM
  • Resolved: anti-HBs + anti-HBc total
  • Chronic: HBsAg ≥ 6 mo
  • Vaccinated: anti-HBs only
  • Window: anti-HBc IgM (between HBsAg and anti-HBs)

355.2.1.4 Chronic HBV Phases

  • Immune tolerant
  • Immune active (HBeAg+ or HBeAg-)
  • Inactive carrier
  • HBsAg loss

355.2.1.5 HBV Treatment Indications

  • HBeAg+: HBV DNA > 20,000 + ALT > 2x ULN
  • HBeAg-: HBV DNA > 2,000 + ALT > ULN
  • Cirrhosis with detectable DNA
  • Pregnancy + high viral load
  • IS / chemotherapy

355.2.1.6 HBV First-Line Antivirals

  • Entecavir (high barrier)
  • Tenofovir (TDF/TAF)
  • Long-term often lifelong

355.2.1.7 HCV Treatment (DAAs)

  • All chronic HCV should be treated

  • 95% cure

  • 8-12 weeks oral

355.2.1.8 HCV Pan-Genotypic DAAs

  • Sofosbuvir + velpatasvir (Epclusa) 12 wk
  • Glecaprevir + pibrentasvir (Mavyret) 8 wk
  • Sofosbuvir + velpatasvir + voxilaprevir (Vosevi) for retreatment

355.2.1.9 HCV + HBV Reactivation

  • Screen HBsAg + anti-HBc before DAA
  • Antiviral prophylaxis if positive

355.2.1.10 HCC Surveillance

  • Chronic HBV (especially Asian male > 40, female > 50, family hx) + cirrhotic
  • US ± AFP every 6 months

355.2.1.11 HBV Reactivation Risk

  • Chemo / IS (especially rituximab)
  • Screen + prophylaxis with entecavir or tenofovir

355.2.1.12 Bulevirtide

  • HDV entry inhibitor
  • FDA 2023
  • Subcutaneous daily

355.2.1.13 HEV in Pregnancy

  • 10-25% mortality in 3rd trimester
  • Genotypes 1, 2 in developing countries
  • Supportive care

355.2.1.14 HEV Chronic

  • Immunocompromised (organ transplant)
  • Ribavirin × 3 months

355.2.1.15 Key Trials

  • Multiple DAA trials (ION, ASTRAL, ENDURANCE) for HCV
  • ALLY-3 + others for liver disease
  • Many for HBV functional cure (emerging)

355.2.2 易混淆比范

Virus Transmission Chronic Vaccine Treatment
HAV Fecal-oral No Yes Supportive
HBV Blood/sexual Yes (variable) Yes Entecavir, tenofovir
HCV Blood Yes (high) No DAAs (8-12 wk; cure > 95%)
HDV Blood (+HBV) Yes (often severe) (HBV protective) Bulevirtide; PEG-IFN
HEV Fecal-oral Rare China only Ribavirin (chronic)

355.2.3 Special Topics

355.2.3.1 Vertical Transmission HBV

  • High risk if HBeAg+ or high viral load
  • Mother-to-child prevention:
    • HBIG + HBV vaccine to newborn at birth
    • Maternal tenofovir if HBV DNA > 200,000 IU/mL (3rd trimester)
    • Reduces transmission

355.2.3.2 HCV Pre-Treatment Workup

  • HCV RNA + genotype (or pan-genotypic)
  • Liver fibrosis
  • HBV screening (reactivation risk)
  • HIV screening
  • Drug interactions check
  • Renal + hepatic function

355.2.3.3 Healthcare Worker Exposures

  • HBV: PEP with HBIG + vaccine
  • HCV: monitor; treat if seroconverts
  • HIV: PEP per protocol