Non-A, non-B hepatitis after experimental transmission of malaria by inoculation of blood.

In a 1969 prisoner volunteer study of malaria transmission by blood inoculation, six persons were subinoculated sequentially, and acute hepatitis occurred in the last four (sequential study). Subsequently, another 15 volunteers receiving malaria-rich blood from 14 different donors were followed prospectively (prospective study), and hepatitis developed in six. Incubation periods were shorter but serum transaminase levels were higher for the cases of hepatitis occurring in the sequential study than in the prospective study. Although the illnesses were clinically mild, elevations in transaminase levels persisted for more than six months in five and fluctuating transaminase activities were observed in nine of the 10 affected persons. In addition, an 11th prisoner developed sporadic hepatitis. Neither known human hepatitis viruses nor malaria could be implicated in these cases, which were classified as non-A, non-B (NANB) hepatitis. The data suggested that the viremia of short-incubation NANB hepatitis may begin within the first week after inoculation, confirmed that NANB hepatitis may be transmitted either percutaneously or nonpercutaneously, and provided further evidence that there is more than one NANB agent.