Laboratory Studies
Evaluation of the potential primate vector
To avoid delaying wound cleansing and forcing the virus deeper into the wound (even after wound cleansing), obtain the exposure-directed primate virus cultures from buccal mucosa (for saliva exposure), conjunctivae, and the urogenital area (for urine exposure). If a cage was involved, acquire swab cultures from the monkey that was most recently housed there.
Because herpes B is a class 4 pathogen, cultures should be performed only at a designated reference laboratory.
Serologic evaluation of the exposed patient
If frozen serum from the last 6 months is not available, acquire, freeze, and store a serum sample.
Obtain a follow-up serum sample approximately 3 weeks after exposure or after the onset of illness (as close to 3 wk as possible) to test with the initial specimen for herpes B virus seroconversion.
Perform serologies in a reference laboratory to minimize cross-reacting HSV antibodies. Although further research is required, newer recombinant DNA techniques may allow for differentiation of herpes B virus infection from HSV infection. [5]
Some human cases of herpes B virus infection have resulted in a slow or minimal rise in virus-specific antibody, confounding serological confirmation.
Polymerase chain reaction
Polymerase chain reaction (PCR) technology may permit faster and more accurate assessment of both human and primate cases. Newer studies are aimed at developing a PCR test that is not only sensitive but also specific, allowing for differentiation from HSV. [6]
Other Tests
Veterinary evaluation of monkeys
The importance of evaluating the primate should be weighed against the potential of further injuries if the monkey must be recaptured without anesthesia.
After anesthesia, the monkey should be examined for oral lesions, genital lesions, or conjunctivitis.
High-risk exposure includes any injury associated with an ill, immunocompromised, or lesioned animal.
Remember that asymptomatic shedding of herpes B virus may occur and is more likely during breeding season or times of stress.
Serial serologies can be obtained from the primate because a rise suggests primary infection and a higher risk of viral shedding. Stable serologies do not predict shedding, which occurs in only 2-3% of cases.
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This is a photo of long-tailed macaques socializing in the wild. The long-tailed macaque, Macaca fascicularis, is a major reservoir for the herpes B virus. (Photo courtesy of Carel van Schaik)
