355.4 📋 章末速蚘 Summary

355.4.1 🔑 䞀句話瞜結

Viral hepatitis 五倧型(1) HAV — RNA, fecal-oral, self-limited acute (no chronic), vaccine available; (2) HBV — DNA, parenteral/sexual/perinatal, chronic in 5% adult / 30% child / 90% perinatal, 台灣 historically high (15%+ pre-vaccine, now reduced with universal vaccination + maternal antiviral); treatment entecavir or tenofovir (TDF/TAF) long-term; HCC surveillance; (3) HCV — RNA, parenteral mainly (IDU, transfusion pre-1992, healthcare exposure), chronic in 75-85% (highest), DAAs (direct-acting antivirals) cure > 95% with 8-12 weeks oral therapy — sofosbuvir + velpatasvir (Epclusa), glecaprevir + pibrentasvir (Mavyret), pan-genotypic; all chronic HCV should be treated; (4) HDV (delta) — defective RNA virus requiring HBV co-infection; bulevirtide (Hepcludex, FDA 2023) entry inhibitor; co-infection vs superinfection; (5) HEV — fecal-oral (genotypes 1,2 water-borne developing; 3,4 zoonotic pigs/deer developed); usually self-limited but severe in pregnancy (10-25% mortality 3rd trimester) and chronic in immunocompromised (transplant — ribavirin × 3 mo)HBV serology key patterns: acute (HBsAg + anti-HBc IgM), resolved (anti-HBs + anti-HBc total), chronic (HBsAg ≥ 6 mo), vaccinated (anti-HBs only); HBV phases: immune tolerant → immune active (HBeAg+ or HBeAg-) → inactive carrier → HBsAg loss; HBV treatment indications: HBeAg+ DNA > 20,000 + ALT > 2x ULN; HBeAg- DNA > 2,000 + ALT > ULN; cirrhosis with DNA; pregnancy high VL; IS/chemo; HBV reactivation: screen HBsAg + anti-HBc before chemo/rituximab/IS + prophylactic antiviral if positive; HCC surveillance: chronic HBV (especially Asian male > 40 / female > 50 / family hx) + cirrhotic — US ± AFP every 6 months; vaccines: HAV (2 doses), HBV (3 doses universal newborn); no HCV vaccine; HEV vaccine in China only; emerging HBV functional cure (HBsAg loss): bepirovirsen siRNA + capsid inhibitors + therapeutic vaccines。

355.4.2 💊 治療粟芁

  • HAV / HEV acutesupportive only; vaccination prevention; immune globulin post-exposure
  • HBV chronic treatmententecavir (Baraclude) 0.5 mg daily OR tenofovir disoproxil fumarate (TDF) 300 mg daily OR tenofovir alafenamide (TAF, less kidney/bone toxicity) 25 mg daily — first-line; long-term often lifelong; PEG-IFN finite course in select younger non-cirrhotic
  • HBV prophylaxis pre-IS/chemoentecavir or tenofovir, especially with rituximab (highest risk) + chemo + TNF inhibitors + long-term steroids
  • HCV treatmentpan-genotypic DAAs — sofosbuvir + velpatasvir (Epclusa) 12 weeks OR glecaprevir + pibrentasvir (Mavyret) 8 weeks (treatment-naive non-cirrhotic) OR sofosbuvir + velpatasvir + voxilaprevir (Vosevi) for treatment-experienced; check HBV co-infection (HBsAg + anti-HBc) before DAA initiation + prophylactic antiviral if positive (reactivation risk)
  • HDVbulevirtide (Hepcludex, FDA 2023) subcutaneous daily entry inhibitor; PEG-IFN-α older limited efficacy
  • HEV chronic (immunocompromised)ribavirin × 3 months (60-80% cure) + reduce immunosuppression if possible + PEG-IFN selected
  • HBV pregnancy + high VL > 200,000 IU/mLtenofovir 3rd trimester to prevent vertical transmission + HBIG + HBV vaccine to newborn at birth
  • vaccinationsHAV (2 doses, ≥ 95% efficacy) + HBV (3 doses universal newborn, anti-HBs ≥ 10 mIU/mL = immune) + no HCV vaccine; consider HAV/HBV for HCV-infected
  • HCC surveillanceUS ± AFP every 6 months for chronic HBV high-risk (Asian male > 40, female > 50, family history) + all cirrhotic patients

355.4.3 🎯 盧醫垫的考前提醒

  1. chronic progression rates differ markedlyHAV never; HBV 5% adult / 30% child / 90% perinatal; HCV 75-85% (highest of all); HDV high; HEV rare except immunocompromised
  2. HBV serology key patternsacute (HBsAg + anti-HBc IgM), resolved (anti-HBs + anti-HBc total), chronic (HBsAg ≥ 6 months), vaccinated (anti-HBs only — no anti-HBc), window (anti-HBc IgM only between HBsAg and anti-HBs)
  3. HBV phases of chronic infectionimmune tolerant (HBeAg+ high DNA normal ALT) → immune active HBeAg+ chronic hepatitis (high DNA + elevated ALT — treat) → immune active HBeAg- chronic hepatitis (variable DNA + elevated ALT — treat) → inactive carrier (low DNA, normal ALT) → HBsAg loss
  4. HBV first-line treatmententecavir or tenofovir (TDF/TAF) — long-term often lifelong; high barrier to resistance; suppresses DNA + improves ALT + slows progression
  5. HCV revolution since 2014: DAAs (direct-acting antivirals) cure > 95% in 8-12 weeks oral therapy; all chronic HCV should be treated (USPSTF Class A) including older patients + advanced fibrosis
  6. HCV pan-genotypic regimenssofosbuvir + velpatasvir (Epclusa, 12 wk), glecaprevir + pibrentasvir (Mavyret, 8 wk for naive non-cirrhotic), sofosbuvir + velpatasvir + voxilaprevir (Vosevi, for treatment-experienced)
  7. HCV + HBV reactivation riskscreen HBsAg + anti-HBc before DAA initiation; antiviral prophylaxis if HBsAg+; can occur even in resolved HBV (anti-HBc+ only) for severe IS
  8. HBV reactivation during chemotherapy/ISrituximab highest risk; screen + prophylactic antiviral with entecavir or tenofovir for all HBsAg+ + many anti-HBc+
  9. HEV in pregnancy 3rd trimester catastrophic: 10-25% mortality (genotypes 1, 2 developing countries); supportive only; no specific antiviral safe
  10. HCC surveillance every 6 months with US ± AFP for chronic HBV (especially Asian male > 40 / female > 50 / family hx HCC) + all cirrhotic from any cause; emerging biomarkers (PIVKA-II/DCP)