Serologic Characterization of Adenoviruses Isolated from Chimpanzees Associated with Viral Hepatitis∗

Chimpanzees and certain other nonhuman primates have been implicated in recent years in the transmission of viral hepatitis to their human caretakers and to other contacts (1–6). Mounting epidemiologic evidence for such transmission is documented by more than 100 human cases of the diseas. This evidence supports the postulate that certain nonhuman primates act as carriers of the etiologic agent of human viral hepatitis or of a disease so closely related as to be indistinguishable from it by clinical, biochemical, and histologic findings. Liver lesions compatible with those of viral hepatitis have been found in several such “carrier” animals and also in other primates spontaneously or experimentally ill with the disease but not implicated in human transmission (4, 7). More recently, inoculation of infective material from human patients with viral hepatitis into certain species of small New World primates has produced a serially transmissible disease highly suggestive of hepatitis (8). Hillis (4) reported the isolation of viral agents from a group of 25 chimpanzees, 9 of which were specifically associated with either spontaneous or experimental hepatitis. The investigation here reported was conducted in an attempt to relate the agents isolated from these nine hepatitis-associated primates to known viruses. The study presents evidence that seven of the agents are members of the adenovirus group, each of which is serologically related to a specific serologic type of human adenovirus. Methods. Viral agents, after 2–3 serial tissue-culture passages in primary chimpanzee kidney cells (ChKC) were inoculated into monolayer tube cultures of primary human embryonic kidney (HEK) and rhesus monkey kidney cells (MKC) a 1:10 final dilutions of the previous ChKC passage in maintenance medium (MM). The latter consisted of Medium 199 with 10% fetal bovine serum and standard tissue-culture dosages of penicillin, streptomycin, and amphoterocin B.