Herpesvirus papio 2: Alternative antigen for use in monkey B virus diagnostic assays

Background and Purpose: Serologic testing for antibody to monkey B virus (BV) in macaque sera is problematic due to the biohazardous nature of BV and BV antigens. Herpesvirus papio 2 (HVP2), a herpesvirus of baboons, is more closely related genetically and antigenically to BV than is human herpes simplex virus 1 (HSV1). The potential for use of HVP2 relative to HSV1 as an alternative test antigen for detection of anti-BV antibody in macaque sera was assessed. Methods: Standard ELISA formats were developed, using BV-, HVP2-, and HSV1-infected cell extracts. Performance of the HVP2 and HSV1 tests was assessed relative to that of the BV test. Results: Using the BV antigen ELISA, 349 sera from 7 macaque species were tested, and results were classified as positive (253), negative (94), or suspect (2). The ELISA using HVP2 antigen detected 98.0% of BV-positive sera (248 of 253), whereas the HSV1-based ELISA detected only 96.0% (243 of 253). All three ELISAs identified the same two samples as suspect, and the HSV1 ELISA identified three additional BV-positive sera as suspect. Conclusions: The HVP2 antigen- based ELISA was equal in sensitivity and specificity to the BV antigen-based ELISA and was superior to the HSV1 ELISA for detection of BV-positive macaque sera. In addition, the HVP2 ELISA has greater laboratory safety, compared with BV antigen use for ELISA testing.