An outbreak of tuberculosis in pigs and cattle caused by Mycobacterium africanum.

An outbreak of tuberculosis in pigs and cattle caused by Mycobacterium africanum produced lesions in the pigs similar to those caused by M tuberculosis, M bovis and M avium, with caseation in the lymph nodes of the head and in the jejunal lymph nodes. Bacteriological examination of the dysgonic mycobacteria isolated showed that they were M africanum I. The intradermal tuberculin test was very reliable in pigs, differentiating between mammalian and avian reactions, and the results of the test were in accordance with the lesions found at meat inspection. No clinical signs were observed during the outbreak, and the infection was neither serious nor progressive. There were no lesions in the tuberculin-positive cattle. The source of the infection remains unknown.