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Hepatitis A-G

Clinical Classification

Infectious hepatitis - hepatitis A and E viruses

Enterically transmitted

No chronic sequelae

Infectious hepatitis - hepatitis B, C, D viruses

Blood and body fluid transmission

Serious chronic sequelae

Possible

Hepatitis A Virus

First characterized in 1973

RNA virus (member of enterovirus group)

Present in large quantity in stool of infected individuals

Lesser quantities in serum and saliva

Can be grown in vitro

Clinical Features

Incubation period 30 days (range 15-50)

Often asymptomatic in childhood

<10% icteric under 6 years of age

70-80% icteric in adolescence/adulthood

Fulminant hepatitis is rare

<0.5% mortality in children

No known chronic sequelae or carrier state

Prevention

Immune serum globulin: Given ASAP within 14 days post exposure

80-90% efficacy

_ Vaccine

94-100% efficacy

Recommended for high-risk individuals, such as travelers to endemic areas, homosexual or bisexual men, drug users, chronic liver disease, children in locales with high endemic rates

B Virus

Member of hepadnavirus family with partly single-stranded DNA

Dane particle is probably complete virion and contains HBsAg

Incomplete forms (spherical and filamentous particles) also contain HBsAg

Virion cores (HBcAg) are contained within the incomplete forms

 HBeAg exists in serum and on hepatocytes

Jaundice

_ Antigenic and Genetic Variation

Multiple antigenic specificities of HBsAg are

Multiple viral "quasispecies" exist in persistently infected hosts

B Virus

 

Hepatitis B Virus

 

Clinical Features

Incubation 60-90 days