Naturally occurring tuberculosis caused by Mycobacterium bovis in brushtail possums (Trichosurus vulpecula): III. Routes of infection and excretion

Authors: Morris RS, de Lisle GW, Jackson R, Yates GF, Cooke MM, Coleman JD
Publication: New Zealand Veterinary Journal, Volume 43, Issue 7, pp 322-327, Dec 1995
Publisher: Taylor and Francis

Animal type: Possum, Wildlife
Subject Terms: Bacterial, Disease transmission, Disease/defect, Epidemiology, Mycobacterial, Pathology, Zoonosis, Infectious disease, Public health
Article class: Scientific Article

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Abstract: Mycobacterium bovis  was cultured from nine of 25 (36%) tracheal washings but not from any of 38 urine and 38 faecal samples from tuberculous possums cross-sectionally sampled from the wild. One of three tracheal washings, one of three urine samples and one of three faecal samples from terminally ill possums were culture-positive. The respiratory route is implicated as the major route of excretion of Mycobacterium bovis from naturally infected possums in horizontal transmission. Tuberculosis was observed in two young possums and was evidence of probable pseudo-vertical transmission via the respiratory route or ingestion of milk. Discharging fistulae were present in 22 of 71 (31%) cross-sectionally sampled tuberculous possums and were associated with relatively advanced disease. Although the frequent involvement of superficial lymphocentres in early stage disease could not be explained satisfactorily, the respiratory route was implicated as the main route of infection from indirect evidence.

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