Additional evidence for more than one agent of human non‐A, non‐B hepatitis. Transmission and passage studies in chimpanzees

Abstract

Evidence supporting the existence of 2 agents of human non-A, non-B hepatitis was obtained by the inoculaiton of chimpanzees sequentially with serum from a chronically infected human (inoculum l) and with fibrinogen prepared from pooled plasma (inoculum IV) , each of which had transmitted non-A, non-B hepatitis of humans. Passage inoculations of serum samples obtained during the acute stages of chimpanzee infections transmitted by the agent in inoculum I or IV also transmitted non-A, non-B hepatitis to additional chimpanzees. Transmission and passage of the agent in inoculum IV were conduced in chimpanzees which previously had recovered from infection by the agent in inoculum I. Cytoplasmic tubules in hepatocytes, which have been described during non-A, non-B hepatitis, were observed by EM in liver biopsies obtained during all infections transmitted by the agent in inoculum I. These cytoplasmic tubules were not detected in liver biopsies from chimpanzees infected by inoculum IV, except in 1 chimpanzee inoculated by inoculum IV without prior exposure to the agent in inoculum I. The cytoplasmic tubules observed in this study were composed of transverse bands arranged with a periodicity of .apprx. 17 nm. Evidently, 2 different agents or distinct serotypes of human non-A, non-B hepatitis were present in these inocula, although reactivation of latent infection or reinfection could not be ruled out completely.