The rise and fall of tuberculosis in a free-ranging chacma baboon troop inthe Kruger National Park

A single troop of free-ranging chacma baboons (Papio ursinus) was found to be infected with tuberculosis caused by Mycobacterium bovis. It is assumed that some members of the troop originally became infected when feeding on a tuberculous carcass in the veld or on tuberculous material scavenged at a nearby post mortem facility. Subsequently, apparent aerosol transmission to ok place while sleeping in an unused room. Oral transmission probably also occurred due to continuous contamination of the floor of this room and the common, narrow access (a train bridge crossing the Sabi River) to it with f aeces and urine. A macroscopic prevalence of 50 % was found and the disease was noted to progress rapidly in infected baboons. A variety of organs had typical tuberculous lesions, of which the spleen, lungs and mesenteric lym ph nodes were consistently, grossly affected. Using Restriction Fragment Le ngth Polymorphism analysis, ail but one of the baboon isolates were found t o be identical to the most common African buffalo (Syncerus caffer) isolate (genotype 1) in this Park. The opportunistic sleeping facility was made in accessible to the troop, which was forced to revert to sleeping in trees. A follow-up survey six months after closure, demonstrated that the disease h ad disappeared from the troop, and that no spillover infection had occurred into neighbouring troops.