Mycobacterium tuberculosis in a Primagam negative wild caught captive olive baboon (Papio anubis) in Ethiopia

Abstract

A free-roaming wild olive baboon (Papio anubis) was caught in the compound of a hospital and kept in captivity pending reintroduction to the wild. The animal had a sporadic dry cough but was TB negative on the blood-based assay PRIMAGAM (IFN-γ test). Six years later, the animal was found dead without any prior clinical signs. The lungs were severely affected. Laboratory analysis included Ziehl-Neelsen staining, GenExpert, culture, deletion typing and spoligotyping. M. tuberculosis was isolated. The spoligotype was SIT 53 (lineage 4) and no Rifampicin resistance was detected. This case report raised challenges on accurate diagnosis of TB in Non-Human Primates in Ethiopia, the question of latency in baboon and the lack of spread of a highly virulent TB strain in the Non-Human Primate colony. It also highlighted the potential role of TB transmission between Non-Human Primates and people in Ethiopia with impacts as well on public health as on primate conservation.

Key words: Baboon; diagnostics; Ethiopia; Mycobacterium tuberculosis; tuberculosis