214.1 🎓 醫孞生版

214.1.0.1 📌 䞀頁重點

  • Virus: ssRNA Flaviviridae (hepacivirus)
  • 6 genotypes (1-6); genotype 1 most common globally; 3 common Asia; genotype 4 Egypt
  • Transmission:
    • Blood: IDU (#1 in developed countries), transfusion (pre-1992 USA, ongoing in unscreened resource-limited)
    • Healthcare: nosocomial (Egypt iatrogenic outbreak — global highest prevalence)
    • Sexual: low risk overall, higher in MSM + HIV+
    • Vertical: 5-10% if mother viremic; risk higher with HIV+ co-infection
    • Tattoo, piercing, acupuncture: unsterile equipment
  • Global Burden:
    • ~ 58M chronic HCV (WHO 2024)
    • 290K deaths/yr (cirrhosis + HCC)
    • WHO 2030 elimination goal: 90% diagnosis + 80% treatment access + 65% mortality reduction
  • Clinical:
    • Acute HCV (10-20% spontaneous clearance): usually asymptomatic; sometimes mild hepatitis
    • Chronic HCV (~ 80%): largely asymptomatic until cirrhosis (20-30 yr)
    • Cirrhosis (20% in 20-30 yr without treatment)
    • HCC (3-5% per year in cirrhotic HCV)
    • Extrahepatic:
      • Mixed cryoglobulinemia (5-25% of chronic HCV)
      • Type II + III cryoglobulinemic vasculitis (rash, neuropathy, GN)
      • Membranoproliferative GN (MPGN)
      • B-cell lymphoma (NHL — splenic marginal zone, DLBCL)
      • Porphyria cutanea tarda
      • Sjögren’s-like sicca
      • Type 2 diabetes (insulin resistance)
  • Diagnosis:
    • Anti-HCV antibody (initial screening)
    • HCV RNA PCR quantitative (active infection)
    • Genotype (less critical now with pan-genotypic DAAs)
  • Treatment:
    • Direct-Acting Antivirals (DAAs):
      • Sofosbuvir/Velpatasvir (Epclusa) — pan-genotypic 12 wk, > 95% SVR
      • Glecaprevir/Pibrentasvir (Mavyret) — pan-genotypic 8 wk, > 95% SVR
      • Sofosbuvir/Velpatasvir/Voxilaprevir (Vosevi) — salvage 12 wk
    • SVR12 (Sustained Virologic Response at 12 weeks post-treatment) = cure
    • No ribavirin needed for most modern regimens (except some salvage)
    • No interferon needed (DAA-only era)
  • WHO 2030 Elimination Strategy:
    • Mass screening (especially birth cohorts in USA, high-risk groups globally)
    • Universal access to DAAs (price reductions in many countries)
    • Harm reduction for IDU (syringe services)
    • Vertical transmission prevention
  • No vaccine yet (development challenges due viral diversity); subunit + viral vector candidates in trials

214.1.0.2 1⃣ Virology

214.1.0.2.1 Structure
  • 55-65 nm enveloped
  • ssRNA, ~ 9.6 kb
  • 10 viral proteins (structural + non-structural)
  • Key targets:
    • NS3/4A protease (target of glecaprevir, voxilaprevir)
    • NS5A (target of velpatasvir, pibrentasvir)
    • NS5B polymerase (target of sofosbuvir — first DAA breakthrough)
214.1.0.2.2 Genotypes
Genotype Geography
1 (1a, 1b) USA + Europe + worldwide (most common globally)
2 USA + Europe
3 South Asia (India, Pakistan), Eastern Europe
4 Egypt (highest national prevalence ~ 10% from iatrogenic outbreak), Africa
5 South Africa
6 SE Asia (Vietnam, Cambodia)
214.1.0.2.3 Mutations + Resistance
  • Quasispecies (high mutation rate)
  • Resistance-associated substitutions (RAS): NS5A polymorphisms reduce response in some genotypes
  • Modern DAAs have high barrier to resistance; testing routine in salvage cases

214.1.0.3 2⃣ Epidemiology

214.1.0.3.1 Global
  • ~ 58M chronic HCV (WHO 2024)
  • 290K deaths/yr
  • Egypt: highest prevalence historically (~ 10% pre-DAA era, dropped substantially with mass treatment)
  • USA: ~ 2.5M Americans
214.1.0.3.2 Transmission
  • IDU: 50%+ of cases in developed countries; needle/syringe sharing
  • Pre-1992 transfusion (USA): historical large cohort
  • Healthcare-associated: nosocomial outbreaks (improper sterilization, contaminated multidose vials)
  • Egypt iatrogenic: schistosomiasis treatment campaigns (1960s-80s) with shared injection equipment → global highest prevalence
  • Sexual: low risk overall; higher in MSM (especially HIV+, drug-using contexts) + chemsex
  • Vertical: 5-10% if mother viremic; ~ 20% if HIV co-infection
  • Tattoo, piercing: unsterile equipment
  • Hemodialysis: nosocomial historically; current strict infection control
214.1.0.3.3 Risk Groups
  • IDU
  • Blood transfusion pre-1992 USA
  • MSM (especially HIV+)
  • Children of HCV-positive mothers
  • Healthcare workers (occupational exposure)
  • Tattoo / piercing recipients (unregulated)
  • Foreign-born from high-prevalence regions
  • Hemodialysis patients (historical)
  • HIV co-infection
214.1.0.3.4 USA Birth Cohort Recommendation
  • Universal HCV screening for all adults ≥ 18 yr at least once (USPSTF 2020 + 2024 update)
  • Prior: 1945-1965 birth cohort (now updated to universal)
  • Pregnant women: screening
  • High-risk groups regardless of age

214.1.0.4 3⃣ Clinical

214.1.0.4.1 Acute HCV
  • 6-7 wk incubation
  • 75-85% asymptomatic
  • 15-25% symptomatic: mild flu-like + mild hepatitis
  • 15-20% spontaneous clearance (more likely if symptomatic acute, female, younger, certain HLA, IL-28B genotype)
  • 80% develop chronic
214.1.0.4.2 Chronic HCV
  • Mostly asymptomatic until cirrhosis
  • Fatigue (common but non-specific)
  • Cirrhosis develops in 20% over 20-30 years (faster in some — alcohol, HIV, age at infection)
  • HCC in cirrhotic 3-5% per year
  • ALT often mildly elevated (or normal in some)
  • Liver biopsy / non-invasive fibrosis (FibroScan, FIB-4)
214.1.0.4.3 Cirrhosis Decompensation
  • Ascites, variceal bleed, hepatic encephalopathy, jaundice, hepatorenal syndrome
  • 5-yr mortality 50% without transplant
214.1.0.4.4 HCC
  • Surveillance: liver US + AFP q6 months in cirrhotic
  • Treatment: same as HBV-HCC (atezolizumab+bevacizumab, lenvatinib, etc.)
214.1.0.4.5 Extrahepatic Manifestations
214.1.0.4.5.1 Mixed Cryoglobulinemia
  • 5-25% of chronic HCV have detectable cryoglobulins (most asymptomatic)
  • Symptomatic cryoglobulinemic vasculitis:
    • Palpable purpura (lower extremities)
    • Arthralgia
    • Peripheral neuropathy
    • Glomerulonephritis
  • Treatment: DAAs (HCV eradication often resolves cryo)
214.1.0.4.5.2 Membranoproliferative Glomerulonephritis (MPGN)
  • HCV + cryoglobulinemia association
  • Hematuria, proteinuria, hypertension
  • ACEi/ARB + HCV treatment
214.1.0.4.5.3 B-cell Lymphoma
  • Splenic marginal zone (most strongly associated)
  • DLBCL
  • Treatment of HCV may regress lymphoma
214.1.0.4.5.4 Porphyria Cutanea Tarda
  • HCV association
  • Photosensitive skin lesions
  • Treatment: HCV therapy + phlebotomy
214.1.0.4.5.5 Lichen Planus, Type 2 Diabetes Insulin Resistance, Sjögren-like, Autoimmune Thyroiditis
  • Various associations
  • Sometimes resolve with HCV cure

214.1.0.5 4⃣ Diagnosis

214.1.0.5.1 Anti-HCV Antibody
  • Screening test
  • ELISA, > 95% sens/spec
  • Positive in chronic + past resolved (cannot distinguish active vs resolved)
214.1.0.5.2 HCV RNA PCR (Quantitative)
  • Confirms active infection
  • Cutoff > 12 IU/mL (sensitive)
  • Quantitative viral load (less critical for DAA decisions)
214.1.0.5.3 Genotype
  • Less critical now (most DAAs pan-genotypic)
  • May guide salvage / specific regimens
  • Reflex testing in some labs
214.1.0.5.4 Resistance-Associated Substitutions (RAS)
  • Test in retreatment / salvage
  • Particularly NS5A polymorphisms
214.1.0.5.5 Liver Fibrosis Assessment
  • FibroScan (transient elastography) — non-invasive primary
  • FIB-4 score (age + ALT + AST + platelet)
  • APRI score (AST + platelet)
  • Biopsy rarely needed
  • Cutoffs:
    • F0-F2: minimal-moderate fibrosis
    • F3: advanced fibrosis
    • F4: cirrhosis
214.1.0.5.6 Liver Imaging
  • US (baseline + HCC surveillance)
  • CT/MRI for HCC characterization
214.1.0.5.7 Other Labs
  • LFTs, INR, bilirubin
  • CBC, platelets
  • HIV + HBV co-infection screen
  • Alpha-1-antitrypsin, ANA, AMA, alpha-fetoprotein (rule out other liver disease)

214.1.0.6 5⃣ Treatment

214.1.0.6.1 Direct-Acting Antivirals (DAAs) — Modern Era
214.1.0.6.1.1 Sofosbuvir/Velpatasvir (Epclusa)
  • Pan-genotypic (1-6)
  • 12 weeks all patients (including cirrhotic)
  • 95% SVR

  • Once-daily fixed combination
  • Renal-friendly
214.1.0.6.1.2 Glecaprevir/Pibrentasvir (Mavyret)
  • Pan-genotypic (1-6)
  • 8 weeks treatment-naive (most patients)
  • 12 weeks for cirrhotic + treatment-experienced (genotype 3)
  • 95% SVR

  • 3 tablets once daily
214.1.0.6.1.3 Sofosbuvir/Velpatasvir/Voxilaprevir (Vosevi)
  • Salvage for DAA-experienced patients
  • 12 weeks
  • Pan-genotypic
214.1.0.6.1.4 Ribavirin
  • No longer routine
  • Reserved for some salvage scenarios
214.1.0.6.1.5 Older Regimens (Largely Replaced)
  • Ledipasvir/Sofosbuvir (Harvoni) — genotype 1, 4, 5, 6
  • Elbasvir/Grazoprevir (Zepatier) — genotype 1, 4
214.1.0.6.2 Treatment Goals
  • SVR12 (Sustained Virologic Response 12 weeks post-treatment completion) = cure
  • 95% achievable with first-line DAAs

  • Re-evaluation 12 weeks post: undetectable HCV RNA = cure
214.1.0.6.3 Re-Infection
  • After cure, re-infection possible if continued risk (IDU, MSM with risk)
  • Counseling on harm reduction
  • Re-treatment if re-infected
214.1.0.6.4 Special Populations
214.1.0.6.4.1 Cirrhotic Decompensated (Child B/C)
  • Adjust regimen (avoid protease inhibitors in severe decompensation)
  • Sofosbuvir/velpatasvir + ribavirin × 12-24 weeks
  • Bridge to transplant in some
214.1.0.6.4.2 HIV/HCV Co-Infection
  • Same DAA regimens
  • Drug interactions with ART (especially boosted PIs + glecaprevir)
  • Refer to interaction checker
214.1.0.6.4.3 Pregnancy
  • DAAs not approved in pregnancy yet (limited data)
  • Sofosbuvir/velpatasvir + similar — under study; safety encouraging
  • Treat post-pregnancy + breastfeeding
214.1.0.6.4.4 Vertical Transmission
  • 5-10% if maternal viremic
  • 20% in HIV co-infection
  • Treat post-delivery
  • Pediatric HCV treatment approved (Mavyret 3+ yr, Epclusa 6+ yr)
214.1.0.6.4.5 Renal Failure / Hemodialysis
  • Glecaprevir/pibrentasvir approved any eGFR (no dose adjustment)
  • Sofosbuvir-containing regimens caution if eGFR < 30 (now approved with monitoring)
214.1.0.6.4.6 Pediatric HCV
  • Mavyret (3+ yr)
  • Epclusa (6+ yr)
214.1.0.6.5 Pre/Post-Treatment Monitoring
  • Baseline: HCV RNA, genotype, FibroScan/FIB-4, LFTs, CBC, HIV, HBV
  • During treatment: rarely needed if patient compliant
  • Post-treatment: SVR12 (HCV RNA 12 wk post-completion)
  • Continued HCC surveillance if cirrhotic (lifelong)

214.1.0.7 6⃣ Prevention

214.1.0.7.1 Harm Reduction
  • Sterile injection equipment (syringe services programs)
  • Opioid agonist therapy (methadone, buprenorphine) — reduces injection
  • Education
  • Naloxone access
214.1.0.7.2 Screening
  • Universal adult screening (USA 2020+)
  • Pregnant women
  • High-risk groups regardless
214.1.0.7.3 Treatment as Prevention
  • Cure stops transmission
  • WHO 2030 elimination needs treatment scale-up
214.1.0.7.4 No Vaccine
  • Development challenges:
    • Viral diversity (quasispecies)
    • Weak natural immunity (most don’t clear)
    • Multiple genotypes
  • Candidates: chimpanzee adenovirus + MVA-vectored (Phase 2)
  • Subunit vaccines in trial
214.1.0.7.5 Pre-Exposure Prophylaxis
  • Not currently used; theoretical research
  • TAF/FTC was studied for HCV PrEP — no efficacy
214.1.0.7.6 Vertical Transmission Prevention
  • No specific intervention currently
  • Maternal cure pre-pregnancy
  • Pediatric treatment after delivery