Epidemiology of selected mycobacteria that infect humans and other animals

This paper provides a summary of salient clinical and epidemiological featu res of selected mycobacterial diseases that are common to humans and other animals. Clinical and diagnostic issues are discussed and related to estima tes of the incidence and prevalence of these diseases among humans. Source of infection, route of transmission and control measures are also presented . The mycobacteria discussed in this paper are Mycobacterium bovis, M. ulce rans, M. leprae and M. avium complex, although this is by no means a comple te list of the mycobacteria common to humans and other animals. Certain gen eralities can be made regarding these species of mycobacteria and their occ urrence in humans and other animals; firstly, current understanding of the epidemiology and control of many of the resultant diseases is incomplete; s econdly, environmental sources other than animal reservoirs may play a role in transmission (with M. leprae perhaps being the exception); and thirdly, the incidence and prevalence of these diseases in many countries of the wo rld are unclear, principally because of the complexity of diagnosis and lac k of reporting systems.