Hepatitis C Virus

One-Sentence Definition

Hepatitis C virus (HCV) is a positive-sense RNA flavivirus causing often silent chronic hepatitis cured in most cases with direct-acting antivirals (DAAs), with parenteral transmission historically dominant.

Taxonomy & Morphology

• Flaviviridae; (+)ssRNA; envelope
• High genetic diversity (genotypes 1–6) — affects DAA choice historically

Virulence Highlights

• Chronic infection common without treatment
• Oncogenic risk (HCC with cirrhosis)
• Extrahepatic manifestations (cryoglobulinemia, etc.)

Clinical Syndromes

• Acute hepatitis (often mild/asymptomatic)
• Chronic hepatitis → cirrhosis, HCC
• Reinfection possible after cure

Diagnosis

Step	Test	Note
Screen	anti-HCV antibody	Past or current infection
Confirm	HCV RNA PCR	Active viremia
Monitor	RNA quant + genotype/subtype	Treatment response

Treatment / Prevention

• DAAs — >95% cure rates in many genotypes
• No vaccine (antigenic variation, lack of durable protective immunity model)
• Harm reduction; blood supply screening

Related Notes

• Hepatitis B Virus · HIV (coinfection) · MOC - Virology
• PCR

Active Recall

1. anti-HCV positive, RNA negative — interpretation?
2. Why no HCV vaccine yet (practical reasons)?
3. Transmission route historically most important?