[Serologic screening for the occurrence of Leptospira antibodies in small wild mammals].

During the five years (1986-1990) free living small mammals were examined serologically for the presence of antibodies to leptospires. Standardized techniques were used in the serological examinations (Sebek, 1979). A total 4634 specimens representing 15 mammalian species were examined. During the studied period, higher occurrence of small terrestrial mammals was noticed in the years 1987-1988. In these years, 61% of specimens out of the total number of trapped animals were examined. The field mice (Apodemus sylvaticus and Apodemus flavicollis) and the common vole (Microtus arvalis) were most frequently examined species, their proportion in the total number being 35.4% and 28.4% respectively. Antibodies to leptospires were demonstrated in 557 cases, i.e. in 12.06%, in specimens representing 10 mammalian species, the higher percentage was recorded only in the year 1988, when antibodies were detected in 15.4%. In 550 cases, i.e. 98.7%, the antibodies were to leptospires of the serovar grippotyphosa and only in 7 cases, i.e. 1.3% to leptospires of the serological group Sejroe. Antibodies to leptospires of the serovar grippotyphosa were found in specimens captured in all localities studied. Antibodies were most frequently detected in the specimens of the common vole (Microtus arvalis) in 6.1% and in both species of field mice (Apodemus sylvaticus and Apodemus flavicollis) in 3.4% of the total number of animals examined. Antibodies to leptospires of the serological group Sejroe were found only in blood sera of the house mouse (Mus musculus) and only in one locality studied. Our results confirmed some previously known facts concerning the distribution and structure of leptospirosis foci on this territory. The study of population dynamics should not be neglected because it is directly proportional to the infestation of individual species as we have evidenced. This fact is most expressive in main reservoir species.