Pathology of Sooty Mangabeys ( Cercocebus atys )

Abstract African non-human primates, the natural hosts of simian immunodeficiency (SIV), represent a fascinating example of biological adaptation and an immunological puzzle. They are able to replicate SIV to high levels without detectable clinical consequences due to the infection and appear to respond normally to other infections. Among this group of natural hosts, the sooty mangabeys ( Cercocebus atys ) are naturally infected with SIVsmm, which has been recognized to be at the origin of HIV-2 infection of humans. In captivity, sooty mangabeys (SMs) often live longer than 20 years, and thus the etiology of their main cause of “natural” disease and death has been reviewed. This chapter describes commonly seen pathological conditions in SMs that either died naturally or required euthanasia based on their clinical status at the Yerkes National Primate Research Center (YNPRC). Macroscopic, microscopic, and clinical findings were reviewed and showed that in the vast majority, the etiology of terminal illness comprised (1) infectious etiologies such as chronic diarrhea/colitis, Streptococcus pneumoniae meningitis, septicemia, nontuberculous mycobacterial infections, and zygomycosis; (2) metabolic conditions including diabetes mellitus due to islet amyloidosis, endometriosis, osteoarthritis, aortic aneurysm, dilated cardiomyopathy, and atherosclerosis; (3) neoplasia such as gastric carcinoma; and (4) like most primates, social housing-related trauma. While degenerative types of disease and the incidence of SIVsmm infections increased with age, SIV infection did not appear to play a role in contributing to morbidity or shortening of lifespan in SMs maintained at YNPRC.