Transmission of non-A, non-B hepatitis agent to chimpanzees from patients of epidemic hepatitis

Two chimpanzees were inoculated intravenously with acute-phase sera obtained from two patients with epidemic hepatitis. They developed histopathologically confirmed hepatitis. Electron microscopic examination of the liver showed peculiar cytoplasmic tubular structures in the hepatocytes. These ultrastructural findings were similar to those described for the livers of chimpanzees inoculated with the F strain of non-A, non-B hepatitis agent derived from a posttransfusion hepatitis case. The chimpanzee that had recovered from hepatitis caused by the F strain of non-A, non-B hepatitis agent was re-challenged with the serum from one of the patients. The chimpanzee developed neither clinical signs nor histological changes of hepatitis. These results suggested that non-A, non-B hepatitis agent was involved not only in post-transfusion hepatitis but also in epidemic hepatitis.