LEPTOSPIRA INFECTION UNDER NATURAL CONDIT IONS IN THE ENVIRONS OF ST-PETERSBURG

The existence of valent natural foci of leptospirosis, stable and poly hostal, under the conditions of urban agglomerations has been establis hed. In an intensively urbanized landscape, the foci of mixed (natural and anthropic) type can be found. Depending on the character of micro landscape in a given zone, the main hosts of leptospires are different species of small mammals in whose populations, as a rule, the circula tion of at least three Leptospira species is observed. Introduction of the 'carriership index' will help determine the role of different spe cies of small mammals as the potential source of leptospires in the fo ci, as well as the proportion of different circulating Leptospira spec ies and their zonal distribution.