Epidemiology and incidence of plague in the world, 1958-79.

During the period 1958 - 79, 46 937 cases of human plague were recorded in the world, but the general downward tendency of plague incidence remained, remembering that 40 484 human cases were recorded in 1950. The current incidence of plague is an indication of the epidemicity of plague in its natural foci. In general, during the period under consideration, plague manifestations followed the universally recognized laws of the epidemicity of the disease. Anthroponotic bubonic plague-the most epidemic form of plague-was noted rarely and in limited areas. A considerable proportion of human plague cases occurred in southern Viet Nam, where the defoliation carried out over vast areas during the military operations is thought to have been one cause of the high incidence.Despite the general downward trend in plague incidence, 30 countries of the world were affected by the disease. Therefore, continuous epidemiological surveillance for plague remains an urgent task confronting the health authorities of the countries having known or potential natural foci.