B virus (Cercopithecine herpesvirus 1) is an occupational hazard for veterinarians and other workers who handle macaque monkeys (rhesus and cynomolgus). Approximately 40 human B virus infections, occurring mainly after bites in animal laboratories, have been reported in the world's medical literature, and a case-fatality rate of about 70% has been observed. Therefore, a systematic prevention program to remove the source, to reduce exposure and to treat the early stages of infection is required.