Epidemiology of the leishmaniases: general considerations.

Recent information from various countries shows that the distribution of the leishmaniases is rapidly changing, as are our concepts of the diverse noso-geographical forms of infection. Concerted efforts should be made to improve our knowledge in these fields to enable the preparation of charts forecasting the spread of the disease.The basic considerations, objectives, and methods of epidemiological investigations carried out in the USSR in natural foci, as well as the classifications used for typing foci, are discussed. The need to use clear-cut epidemiological concepts is particularly stressed.