[The epidemiological transition and the conquest of plague].

In 1971, Abdel R. Omran, the epidemiologist, launched the concepts the epidemic transition and the demographic transition. Assuming that the epidemic and demographic structures of all preindustrial societies were similar, Omran attached these concepts to the epidemic and demographic transitions of the nineteenth century. He indicated that these were the only epidemic and demographic transitions in history. In this paper, it is argued that this assertion is untenable. Historically, there have been many societal transitions implying concurrent and interactive epidemic and demographic transitions. Two major historical events have been selected for illustrative purposes. The emergence of the western demographic system and the advent of plague in 1347 had dramatic impacts on epidemic and demographic conditions. Successful combat of plague, first in Italy, was organized with increasing efficiency from the second half of the fifteenth century on the basis of miasmatic-contagionist epidemiological notions. The antiepidemic organizations developed in this combat were efficient also against most other important epidemic diseases. The rise of antiepidemic organizations contributed to transitional change in epidemic and demographic structures with substantial impact on broader societal processes of modernization. These transitions preceded and conditioned the transitional processes referred to by Omran.