To evaluate the incidence of post-transfusion hepatitis and factors influencing its occurrence, the Transfusion-Transmitted Viruses Study prospectively followed 1513 transfusion recipients from 1974 through 1979. The attack rate for non-A,non-B hepatitis was 10 per cent. The incidence of hepatitis was directly related to the alanine aminotransferase (ALT) level in blood donors. In recipients of multiple transfusions of blood that had no donor-ALT level above 29 IU per liter the attack rate was 6 per cent or less; at higher donor-ALT levels the attack rate increased progressively, reaching 45 per cent in recipients of units with an ALT of 60 IU or greater. A similar relation was observed among recipients of single units of blood. Moreover, hepatitis developed in 10 of 11 recipients of two units with an ALT level of 45 IU or greater. These data indicate that screening blood for ALT levels would reduce the incidence of non-A,non-B post-transfusion hepatitis.

Screening PC units by the reagent strip method resulted in 9.7 units per 1000 being wasted, but prevented two patients from receiving a PC unit containing B. cereus.

No abstract

Experimental transmission of non-A, non-B hepatitis was apparently accomplished in 5 chimpanzees following inoculation with presumably infectious human sera. Administration of sera from implicated donors with normal alanine aminotransferase (ALT) values, as well as from those with abnormal ALT levels, resulted in the development of ALT abnormalities in the inoculated chimpanzees. Transmission from donors with normal ALT values implies that healthy carriers of non-A, non-B virus exist. Evidence is presented which indicates that a period of viremia precedes the clinical illness by at least 12 days.