[Emerging diseases and demography dynamics]

The point of view presented in this work is not that of the epidemiologist interested in the etiology of diseases and their specific effect on mortality rates; but rather the view of the demographer who attempts to establish the influence that diseases have on evolution and population dynamics. It is not until the 19th century that the 'unification microbienne' of the world is reached and one has clinical and statistical data on the major diseases. Consequently, it is not possible to have an exact demographic picture of infectious diseases in their emerging phase. To understand globally this effect one may create a conceptual framework capable of integrating all the aspects of mortality rates: genetic, socio-biological and human. The scheme proposed here allows for a description and at the same time an evaluation of a given historical situation, how a population achieves protection from lethal diseases and what are the factors determining receptivity or resistance to a disease. This approach serves to study the interdependent relations that link all elements involved in a given morbid process.