Herpes B-Virus Specific-Pathogen-Free Breeding Colonies of Macaques (Macaca mulatta): Diagnostic Testing Before and After Elimination of the Infection

Background and Purpose: The National Institutes of Health's (NIH) National Center for Research Resources' (NCRR) Division of Comparative Medicine has funded the establishment of specific pathogen-free (SPF) captive macaque colonies. Herpes B-virus (Herpesvirus simiae, Cercopithecine herpesvirus type 1) has been targeted for elimination. Late seroconversion presents the greatest threat to the integrity of SPF colonies. The purpose of the study reported here was to evaluate that threat through detailed investigation of the patterns of seroreactivity and housing histories in one colony. Methods: From 1990 through 1997, the B-virus Resource Laboratory screened macaques for B-virus, using ELISA or western immunoblot analysis. In 1993, we combined test results and housing histories to verify the seronegative status of one colony. Results: Two groups of latently infected macaques were identified as to time and place of transmission. The infection was eradicated within 3 years (1990–1992), as judged by the absence of true positive seroreactivity in any screened macaques. New infections were not identified in four years of follow-up evaluation. Conclusion: With rigorous surveillance, the SPF status of the colony was achieved and maintained.