Public health implications of marek’s disease virus and herpesvirus of turkeys. Studies on human and subhuman primates

Cynomolgus, rhesus, and bonnet monkeys inoculated with high doses of herpesvirus of turkeys (HVT) or pathogenic Marek’sdisease virus (MDV) were observed for 11-31months. None developed detectable viremia, hematologic abnormalities, or clinical disease.Sera from 3 of 12 monkeys inoculated withHVT reacted against HVT antigen in an immunofluorescence (IF) test, whereas all 8MDV-inoculated monkeys remained negative.Approximately 15 months after initial inoculation, 1 reactor and 1 nonreactor monkeyfrom the HVT-inoculated group were given asecond injection of cell-associated HVT propagated in duck embryo fibroblast (DEF) cells.One reactor and 1 nonreactor from the samegroup received normal DEF cells. Virus-inoculated animals developed IF reactionsagainst HVT, but the 2 animals inoculatedwith normal DEF cells remained negative.Sera from people in 7 different categories, including those with prolonged contact withHVT and MDV, were tested by IF test forHVT and MDV antibody. Of approximately 200sera, 8% had IF reactions. There was noapparent correlation between the extent ofcontact with the 2 viruses and the incidenceof IF reaction. Of 25 sera from Burkitt’s lymphoma patients, 1 serum had a weak (1:5)reaction against MDV antigen. Human andmonkey sera positive by the IF test lackedspecific virus neutralizing activity. The significance of IF reaction, therefore, remainedunclear. These data supported earlier findingsand provided additional circumstantial evidence that MDV and HVT do not constitute apublic health hazard.