Diagnosis and implications of Mycobacterium bovis infection in banded mongooses (Mungos mungo) in the Kruger National Park, South Africa

Abstract

Bovine tuberculosis (bTB) was first diagnosed in the Kruger National Park (KNP) in 1990. Research has since focused on the maintenance host, the African buffalo (Syncerus caffer) and clinically affected lion (Panthera leo). However, little is known about the role of small predators in tuberculosis epidemiology. During 2011–12, we screened banded mongooses (Mungos mungo) in the bTB highprevalence zone of the KNP for Mycobacterium tuberculosis complex members. Fecal swabs, tracheal swabs, and tracheal lavages of 76 banded mongooses caught in cage traps within a 2-km radius of Skukuza Rest Camp were submitted for Mycobacterium culture, isolation, and species identification. Lesions and lymph node samples collected from 12 animals at postmortem examination were submitted for culture and histopathology. In lung and lymph nodes of two banded mongooses, well demarcated, irregularly margined, gray-yellow nodules of up to 5 mm diameter were identified with either central necrosis or calcification, characterized on histopathology as caseating necrosis with epithelioid macrophages or necrogranuloma with calcified centre. No acid fast bacteria were identified with Ziehl– Neelsen stain. We isolated Mycobacterium bovis from lung, lymph node, and liver samples, as well as from tracheal lavages and tracheal swab from the same two banded mongooses. Blood samples were positive by ElephantTB STAT-PAKt Assay for 12 and Enferplexe TB Assay for five animals. Only the two banded mongooses positive on pathology and M. bovis culture were positive on both serologic assays. We provide evidence of bTB infection in banded mongooses in the KNP, demonstrate their ability to shed M. bovis, and propose a possible antemortem diagnostic algorithm. Our findings open the discussion around possible sources of infection and their significance at the human/wildlife interface in and around Skukuza.