“Natural History” means the course of untreated disease.
Hepatitis A
Main Risks: Third World travel, MSM, undercooked shellfish, contact with recent HepA pt / outbreak, daycare
Incubation Period 2-6 weeks
Transaminases rise, to the 1000’s (height is not prognostic)
Symptoms: anorexia, nausea, vomiting, fever, malaise, jaundice
- Symptoms decline as jaundice appears
- Many cases asymptomatic, especially in children
- Uncommon extrahepatic manifestations possible
Lifelong Immunity after infection (100% of persons)
- Rare cases of relapsing disease
Fulminant HepA: 0.1% of cases (high mortality)
- Usually persons with other chronic liver disease
Hepatitis B
Main Risks: Asian immigrant / child of Asian immigrant, MSM, Multiple sexual partners, IDU, partner w/ chronic Hep B
Incubation Period: 2-6 months
Most acute infections are asymptomatic
Most people (90%) clear the virus, remain immune forever (“surface-antibody” positive)
Chronic Hep B: 5-10% of people — HBsAg (“surface-antigen”) positive
- Most of these are just Chronic Carriers (infectious, but don’t get ill)
- Some get Chronic Active Hepatitis, Dx’d by high viral load [HBV DNA >100,000 copies / 20,000 IU], eventually die from cirrhosis or hepatocellular carcinoma
- Most vertically-infected persons eventually get Chronic Active Hepatitis
Hepatocellular Carcinoma can occur at any time in course of Chronic Active Hepatitis, even before advent of cirrhosis
Occult Hep B: screen patients headed for heavy chemotherapy / bone marrow transplant
- If “core-antibody” positive, some risk of reactivation even if HBsAg negative
Hepatitis C
Main Risks: Blood transfusion before 1992 (in US), IDU, MSM with multiple sexual partners
Incubation Period: 6-12 weeks
Most acute infections are asymptomatic
Most people (80-85%) remain chronically infected — Dx’d by positive viral load (HCV RNA)
- 15-20% clear the virus, never get sick, but can get reinfected
Chronic Hep C leads to cirrhosis. Approximate time frame:
- 10% of people in 10 yrs.
- 30% in 30 yrs.
- 50% in 50 yrs.
Hepatocellular Carcinoma usually only occurs after cirrhosis
Genotype and viral load not prognostic, but do predict response to treatment.
DiagnosisDude 