Herpes B Virus Infection

Herpes B virus is relatively benign in the macaque monkey, its natural host.  However, the alpha-herpesvirus can cause rapidly ascending encephalo-myelitis with a fatality rate of approxi-mately 80% if spread to humans.  The transmission of the virus most likely occurs through bites, scratches, splashes, or needle-stick injuries.  It is important that attempts are made to understand the etiology of the virus as well as ways to expedite diagnoses and prevent infection.

  B-virus infection has been most commonly reported in the rhesus and cynomologus macaque.  In the macaque host, B virus causes mild symptoms which may include oral or genital lesions.  B virus is transmitted from a host when virus is shed from herpetic lesions or the affected mucosal sites.  Most cases of human B-virus infection have been associated with

apparently healthy macaques that have asymptomatic shedding of the virus.  How often or how long the host sheds is not yet fully understood.

  These species of macaques are extensively used in biomedical research and, therefore, frequent contact is made between animal care technical staff and the non human primates.  Detection of B virus is imperative to reduce the number of cases of the disease.  It is the role of human and animal physicians to suspect infection early and diagnose it rapidly in order to control human infection.  Taking samples from the exposed human as well as the source animal is important for virus culture and serologic testing.

  Development of diagnostic methods that have the ability to differentiate between Herpes Simplex Virus (HSV) and the B-virus infection are required due to the extreme cross-reactivity of primate alpha-herpesviruses.  Antibody testing by ELISA and western blot, virus isolation testing by cell culture, and virus DNA testing by PCR are the methods most commonly used today.  Direct culture of the B virus itself has been the cornerstone for diagnosis of infection.  This, however, comes with a risk for exposure to the laboratory personnel.  Herpes B virus is a biosafety level 4 pathogen and, therefore, its culture requires a special containment facility.  PCR methods have allowed direct demonstration of the B-virus infection without risk of exposure to a virus culture handling.

  There is a real risk of fatal human infection following exposure to herpes B-virus due to the wide use of macaques in biomedical research.  Personal protective equipment and continuing education on proper handling procedures have curbed the incidence of human exposure.  Further efforts to better understand the biology of B-virus in its natural host is the next step to

identify opportunities to prevent or limit zoonotic B-virus disease.

-by Adam Miller, Ross University

-edited by Dr. Leon Thacker, ADDL

  Director

References

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2. Freifeld AG, Hilliard J, Southers J, Murray M, Savarese B, Schmitt JM, Straus SE: 1995.  A controlled seroprevalence survey of primate handlers for evidence of asymptomatic herpes B virus infection. J Infect Dis 171:1-31-1034.

3. Georgia State University.  Viral Immunology Center.  B-virus information page. www.gsu.edu/ ~wwwvir/VirusInfo/index.html.

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6. Huff JL, Eberle R, Capitanio J, Zhou SS, Barry PA: 2003.  Differential detection of mucosal B virus and rhesus cytomegalovirus in rhesus macaques.  J Gen Virol 84: 83-92.

7. Sawtell NM: 1998.  The probability of  in vivo reactivation of herpes simplex virus type 1 increases with the number of latently infected neurons in the ganglia.  J Virol 72: 6888-6892.

8. Scinicariello F, Eberle R, Hilliard JK: 1993.  Rapid detection of B virus (Herpesvirus simiae) DNA by polymerase chain reaction.  J Infect Dis 168:747-750.

9. Slomka MJ, Brown DW, Clewley JP, Bennett AM, Harrington L, Kelly DC? 1993.  Polymerase chain reaction for detection of Herpesvirus simiae (B virus) in clinical specimens.  Arch Virol 131:89-90.

10. U.S. Department of Health and Human Services, PHS, Centers for Disease Control and Prevention, National Institutes of Health, Biosafety in microbiological and biomedical laboratories, 4^th ed. Washington DC: U.S. Government Printing Office, 1999.

11. Weigler BJ, Hird DW, Hilliard JK, Lerche NW, Roberts JA, Scott LM:1993.  Epidemiology of cercopithecine herpesvirus 1 (B virus) infection and shedding in a large breeding cohort of rhesus macaques.  J Infect Dis 167:257-263.