Viral Hepatitis

Abstract
Tests for the presence of Australia or hepatitisassociated antigen (HAA) and antibody (anti-HAA) were performed on more than 25,000 serum specimens from more than 700 patients with viral hepatitis. Hepatitisassociated antigen was consistently present in sera from patients with MS-2 strain of serum hepatitis (SH); it was not present in MS-1, infectious hepatitis (IH). Hepatitis-associated antigen was detected earlier after a parenteral exposure to SH than after an oral exposure. Antigen appeared two weeks to two months before onset of jaundice; it was transient in 65% of patients, but persisted for four months to 13 years in 35% of children. The average incubation period of IH (MS-1) was essentially the same following an oral or parenteral exposure (32 to 33 days); in SH (MS-2) it was 65 days after parenteral exposure and 98 days after oral exposure. Gamma-globulin consistently neutralized the infectivity of IH (MS-1) serum; in most cases it did not neutralize the infectivity of SH (MS-2) serum.