Experimental Infection of the New World Owl Monkey (Aotus Trivirgatus) with Hepatitis A Virus

Epidemiological studies have demonstrated the susceptibility of the owl monkey (Aotus trivirgatus) to hepatitis A virus, but have not shown an association between infection and histopathological or chemical evidence of liver disease. Therefore, 12 seronegative, colony-bred monkeys were inoculated intravenously with a fecal suspension containing either PA33 strain hepatitis A virus (a strain recovered from a naturally infected Aotus sp.) or HM-175 virus (recovered from a human). Viral antigen was detected by radioimmunoassay in the feces of six monkeys 6 to 17 days after inoculation with PA33 virus, and by 9 to 21 days serum aminotransferase activities were significantly elevated in each. Antibody to the virus developed in each monkey by 28 days after inoculation. Similar findings were noted in five of six monkeys inoculated with HM-175 virus, although the incubation period preceding aminotransferase elevations was somewhat longer (25 to 39 days). Liver biopsies obtained from the 11 infected monkeys demonstrated mild to moderate portal inflammation, as well as random areas of focal necrosis and inflammation extending outward from the portal region. These data confirm the susceptibility of Aotus sp. to hepatitis A virus and indicate that the infection of this primate provides a useful animal model of human hepatitis A.