Hepatitis C
Virus
Epidemiology:
- Hepatitis
C Virus:
- Hepacivirus
- Flaviviridae family
- Enveloped
ssRNA
- 9kb
genome coding for a single polyprotein
- Replicates
by RNA-dependent RNA polymerase
- Unstable
process – virus is inherently unstable giving rise to multiple
genotypes and subtypes even within the same patient
- Proteins
E2 and NS5A inhibit interferon-induced double-stranded RNA-activated
protein kinase involved in the antiviral
immune system
- Transmission:
- Parenteral
- Close
contact
- Incubation
2-26 wk (6-12wk avg)
- ~1.8%
of US population has HCV antibodies
- 70%
have chronic infection (viral DNA in serum)
- Half of
all chronic liver disease
- Routes
of transmission:
- IV
drug use (60%)
- Transfusions
prior to 1991 (10%)
- Sexual
transmission (case risk for transmission is low)
- Homosexuals
higher risk
- Hemodialysis patients
- Healthcare
workers
- Vertical
(6% of births to infected mothers)
Common sites:
Gross features:
Histologic features:
- more
involvement of bile ducts
- no
ground glass cytoplasmic inclusions
- may
have steatosis
Immunophenotype:
Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
- Serology:
- HCV
RNA detectable for 1-3 weeks during acute flares, coincident with transaminase elevations
- In chronic
carriers HCV RNA continues to be detectable generally
- Episodic
elevations in transaminases with intervening normal
or near-normal periods is typical
- Clinical
features:
- High
rate of chronic hepatitis (>50%)
- Acute
infection is generally asymptomatic
- Course
is relatively mild (compared to HBV)
- Rarely
causes fulminant liver failure
- Cirrhosis
in 20% of chronic infected
- Increased
risk of HCC
- Closely
related to Hepatitis G
References:
- Robbins
& Cotran Pathologic Basis of Disease (2005)