Risk for Infection

Persons at greatest risk for B virus infection are veterinarians, laboratory workers, and others who have close contact with Old World macaques or monkey cell cultures. Infection is typically caused by animal bites or scratches, exposure to the tissues or secretions of macaques, or mucosal contact (contact with the eyes, nose or mouth with infected body fluid or tissue. Human infection can also result from indirect contact via, for example, a needlestick injury from a contaminated needle.

Macaques housed in primate facilities usually become B virus positive by the time they reach adulthood. B virus establishes latent infection in macaques and can only be transmitted during active viral shedding into mucosal surfaces. This happens only on reactivation from the latent state, which occurs rarely—most commonly in animals that have been stressed or immunosuppressed.

In late 1997, a worker at a primate center died from B virus infection that developed after biologic material from a monkey was splashed into the worker's eye. In response to this case, CDC formed a working group to reassess the existing recommendations for the prevention, evaluation, and treatment of B virus infection in humans. The group's report, Recommendations for Prevention of and Therapy for Exposure to B virus (Cercopithecine Herpesvirus 1), was published in Clinical Infectious Diseases in 2002. The 2002 report updates previous recommendations and describes the use of newer antiviral agents in post-exposure prophylaxis. (Also see the Prevention section.)

See the Transmission section for details on how to reduce the risk for exposure to B virus.