It is also known as Enterovirus type 72 and is resistant to heat and acid. HBV contains a circular, partly double-stranded DNA genome 3200 nucleotides in length. The particle contains a DNA-dependent DNA polymerase and a reverse transcriptase and replicates via an RNA intermediate. All of these antigens elicit specific antibodies. Clinical presentation of HAV infection varies from subclinical and mild in children to jaundice in adults.
Most disease resolves within two weeks.
Chronicity or fulminant hepatitis is rare. HBV, in contrast, may produce a persistent carrier state in addition to liver damage. Liver failure may predispose those affected to cancer. The possibility of immune complexes with surface antigen can also lead to immune complex disease. Little is known about host defenses against this agent but immune serum does not seem to be an effective prophylactic remedy.