[The noncorrespondence of the geographic ranges of the host and the causative agent].

For the first time the experimental and field studies of Leptospira infections, carried out over the period of 6 years, have revealed that the habitat of striped field mice (Apodemus agrarius Pallas 1778) serving as a host for Leptospira pomona, serovar mozdok, is much wider than the habitat of the infective agent proper. The presence of an animal species highly sensitive to a definite leptospiral serovar and serving as its reservoir at a given locality cannot be regarded as a proof of the presence of the epizootic process without bacteriological confirmation. But, in the absence of homologous Leptospira carriage, intensive leptospiral seroconversion can be attributed to a population other than that of the host.