• The majority of acute viral hepatitis infections are asymptomatic or they can cause an anicteric illness that may not be diagnosed as hepatitis
• Hepatitis A generally causes minor illness in childhood w/ >80% of infections being asymptomatic
  
  • Adults are more likely to produce clinical symptoms

• Hepatitis B, C & D may also be asymptomatic
• Symptomatic hepatitis B will depend on the mode & time of transmission
  
  • Vertical transmission from mother to child is almost always asymptomatic
  • Other routes of transmission are more likely to produce symptomatic disease (30% of cases transmitted by IV drug use are icteric)

Preicteric Phase

• Nonspecific systemic symptoms (eg myalgia, nausea, vomiting, fatigue, malaise w/ discomfort in the right upper quadrant of the abdomen)
• Altered sense of smell or taste, coryza, photophobia, headache, cough, diarrhea, dark urine & serum sickness-like syndrome
• Hepatomegaly, splenomegaly & lymphadenopathy may be seen on physical exam

Icteric Phase

• Jaundice, usually noted after onset of fever or upon lysis of fever

Fulminant Hepatitis

• Development of symptoms of hepatic encephalopathy (eg confusion, drowsiness within 8 weeks of symptoms or within 2 weeks of onset of jaundice)
• Hypoglycemia, prolonged prothrombin time (PT)

Routes of Transmission of Hepatitis

Hepatitis A: Oral-fecal

Hepatitis B: Perinatal, percutaneous, sexual, close person-to-person contact ie by open cuts & sores

Hepatitis C: Blood transfusions, organ transplants, percutaneous (especially IV drug use), sexual, perinatal

Hepatitis D: Sexual, percutaneous especially IV drug use

• Found only in patients w/ hepatitis B since it requires the hepatitis B outer coat

Hepatitis E: Oral-fecal, blood transfusion in endemic areas

Incubation Period

Hepatitis A: 15-50 days

Hepatitis B: 30-180 days

Hepatitis C: 14-180 days

Hepatitis D: 30-180 days

Hepatitis E: 21-60 days

Other Characteristics of Hepatitis Viruses

• Hepatitis B virus contains a DNA nucleic acid while A, C, & E viruses have an RNA nucleic acid
  
  • Hepatitis D has an incomplete RNA & needs the B virus to replicate

• Hepatitis A & E viruses cause epidemics
• Hepatitis B, C, & D viruses may predispose to chronic disease & hepatic malignancy