Detection of antibodies to Herpesvirus saimiri late antigens in human sera

One hundred fifty sera from handlers of squirrel monkeys and 100 sera from individuals who had never handled monkeys were tested by immunofluorescence for antibodies reactive to structural proteins of Herpesvirus saimiri (HVS). Eleven (7.3%) of the occupationally exposed group and 4 (4%) of the noncontact group were seropositive for HVS by immunofluorescence assay, and 10 of these 15 (6.7 and 2%, respectively) were also seropositive for either the major glycoprotein (140 kD) or the major capsid protein (160 kD) of HVS by radioimmunoprecipitation assay. Two sera from handlers of squirrel monkeys, however, recognized many different HVS structural antigens by immunoprecipitation, and it seems unlikely that they could also be cross-reactive antibodies. Since these two sera did not contain antibodies to HVS early antigens or to the nonstructural antigens present in infected owl monkey kidney cells, and follow-up sera collected from the same individuals several months later were negative for antibodies to HVS, these individuals do not appear to have been infected by the virus. The risk that HVS poses to humans appears to be very low.