Detection of reverse transcriptase activity in association with the non-A, non-B hepatitis agent(s).

Particle-associated reverse transcriptase activity was detected in four human serum specimens and in two plasma-derived products, all of which had been shown to transmit non-A, non-B hepatitis (NANBH) to other human beings and/or chimpanzees. Reverse transcriptase activity was also detected in all twelve sera from patients with acute or chronic NANBH. In contrast, reverse transcriptase activity was found in only 2 of 49 serum specimens from healthy plasma donors and laboratory workers. Sucrose density gradient fractions of two of the infectious human sera (peak reverse transcriptase activity at 1.14 g/ml) transmitted NANBH to chimpanzees. Biochemical and enzymatic data indicate that the NANBH agent(s) is a retrovirus or is retrovirus-like.