Chronic Herpesvirus saimiri Infection in an Owl Monkey

An adult owl monkey (Aotus trivirgatus) used for immunologic studies of Herpesvirus saimiri (HVS) developed early, late, membrane, and neutralizing antibodies to HVS approximately 3 weeks after the beginning of the experiment. HVS was isolated by the cocultivation of peripheral blood for over 1 year. No clinical, gross, or histopathologic findings of malignancy were exhibited by the animal. The HVS isolate from the animal was indistinguishable biologically and serologically from the original HVS strain of Meléndez and from an isolate of an experimentally HVS-induced tumor. Inoculation of this isolate into 2 young white-lipped marmosets (Saguinus fuscicollis) produced typical malignant lymphoma and lymphocytic leukemia. Our findings suggested that the virus from the chronically infected animal was oncogenic and that host factors were primarily responsible for determining the disease manifestation of the virus infection. Another owl monkey chronically infected with HVS for over 2 years has remained asymptomatic.