Swine leptospirosis in southern backa district from 1997 to 2001

In a 5 year period 48748 swine blood samples were examined, or 24.52% of the breeding stock. The samples were examined by the method of microscope agglutination, with "live" antigen of 8 leptospira serotypes: L. pomona, L. icterohaemorrhragiae, L. grippotyphosa, L. sejroe, L. tarassovi, L. australis, L. bataviae and L. canicola. During the investigation specific antibodies for leptospira were diagnosed in 280 (0.57%) samples of swine sera. The highest level of seroprevalence for leptospirosis in swine was in the year 1998 with 130 (1.27%) seropositive swines. The lowest seroprevalence level was detected in the years 1999 and 2000 with only 13 seropositive animals (0.13-0.14%). During this period the highest number of seropositive swines was found in the Bečej area, 241 (0.92%). In this period 3 serotypes of leptospira were present: L. pomona, L. icterohaemorrhagiae and L. grippotyphosa. Serotype L. icterohaemorrhagiae was most present on the investigated area (in 94.32% cases), followed by L. pomona (5.31%) while serotype L. grippotyphosa appeared only sporadically in only 0.35% cases. In this period a trend of slight decrease was noticed in swine prevalence for leptospirosis amounting to 0.048% annually. Based on these analyses, it may be expected with 95% certainty that the level of prevalence for leptospirosis in the coming period in this epizootiological area will range from 0.00% to 0.82% of the infected animals