The epidemiology of infectious diseases of livestock.

From the time of the first modern studies of infectious diseases, by Koch, Pasteur, Theiler and their colleagues, it has been clear that laboratory investigation must be complemented by epidemiologic investigation. The measurement of all aspects of the natural history of a disease in naturally affected populations is necessary if we are to rationally design control regimens. Building upon a historic perspective, this paper presents a view of the present status of epidemiology as it pertains to animal disease control, and presents a view of the merits of expanding the use of this science in future animal disease control programs, internationally, in developed and developing countries. The basis for this view lies in adaptation of principles employed in human infectious disease epidemiology, and principles which guide the organization of international disease control agencies.