Hepatitis C

(Gastro 2006;130:225-30 & 231-64. Hepatology 2004;39:1147-71. Hepatology 2002;36:S3-20)

DEFINITION:

A hepatotrophic virus; the liver is the primary site of infection, replication and cellular damage
Chronic hepatitis: presence of clinical, biochemical, and serologic abnormalities for up to 6 months

EPIDEMIOLOGY:

Blood transfusion before 1985: 1/20 (5%) got HCV; After 1990: 1/200,000 (.0005%) got HCV! Has been and remains a very low risk
The number of new cases of HCV has decreased dramatically over the last 10 years
Acute Hepatitis C leads to: Chronicity of HCV 70-85%, Recovery of HCV 15-30% (HCV is a chronic disease)

ETIOLOGIES:

Transmission: percutaneous >>> sexual; ˜ 20% without a clear precipitant
- Needle stick risk: HBV > HCV > HIV
Incubation: 1-4 months
Pregnant women/Vertical Transmission/Breastfeeding: No prophylaxis/vaccine available; See also Liver-Pregnancy Pearls (Chapter 4.25)
- Generally don’t treat, low risk of vertical transmission (5%); HIV co-infection or viral load >2 million (can be 50% transmission)
- According to CDC, breastfeeding is not contraindicated; No transmission via breastfeeding has been documented

PATHOPHYSIOLOGY:

Virus: RNA, linear gene shape, envelope, 50 nm in size; Several genotypes identified, most common: 1-3

CLINICAL MANIFESTATIONS/PHYSICAL EXAM:

Natural History: anorexia, nausea, vomiting, fatigue, abdominal pain, mild fever; jaundice is much less common compared to HAV/HBV
- Acute HCV leads to: 75% being subclinical and 25% leading to jaundice; 15-30% lead to full recovery Fulminant HCV hepatitis very rare (i.e. rarely do you come across and treat acute Hep C)
- Chronic HCV leads to: 70-85% continuing to be chronic, 20-30% of whom develop cirrhosis (after ˜ 20 yrs)
  - i.e. Most will not develop cirrhosis, ? who is at risk-suggestions are: ♂, ETOH use, steatosis, coinfection with HBV or HIV
- Chronic: hepatocellular carcinoma develops in 2-5% of HCV cirrhotics/year (usually after 20-30 yrs)
Extra-hepatic (38% have at least one extra-hepatic symptom): cryoglobulinemia, porphyria cutanea tarda (PCT), MPGN, lymphoma, aplastic anemia

LABORATORY STUDIES: