A naturally occurring outbreak of tuberculosis in a group of imported cynomolgus monkeys (Macaca fascicularis).

This case report describes the diagnosis of tuberculosis (caused primarily by Mycobacterium bovis) in a group of newly imported Chinese origin cynomolgus monkeys. We also describe the use of sedation to enhance the accuracy of evaluation of the intrapalpebral tuberculin skin test using the mammalian old tuberculin reagent and report the first known diagnosis of Mycobacterium paraffinicum in a nonhuman primate. By 48 h after injection during the second tuberculin skin test, 6 of the 80 macaques had developed eyelid reactions ranging from mild (grade 1) to severe (grade 4). Given the range and severity of reactions, we suspected an outbreak of tuberculosis in the group. Because of the nature of the reactions, we sedated the animals at the 72-h evaluation to more closely observe and then palpate the injected eyelid. Evaluation of unsedated animals revealed 22 with a reaction to mammalian old tuberculin. We confirmed these 22 cases and identified an additional 11 animals with reactions when the monkeys were sedated. Mycobacterial culture of tissue from 6 macaques with reactions confirmed M. bovis in 3 animals. In addition, 1 of these 3 animals was culture-positive for both M. bovis and M. paraffinicum, and another was culture-positive for M. avium complex only. The addition of sedation to facilitate visual inspection and then palpation of the injected eyelid of these macaques increased the accuracy of evaluation and understanding of the number and severity of reactions to tuberculin skin testing.