Serological Survey for Leptospirosis in Dairy Cattle in Western Ibaraki Prefecture

Abstract

The microscopic agglutination test was used to survey Leptospira serum antibodies in 200 cows from 6 dairy farms in the western district of Ibaraki Prefecture (Japan). Antibody titres of over 128-fold were defined as above the cut-off value for positive reaction. The tests showed 30 cows from 4 farms to be positive. Three serotypes were used. In the case of Leptospira autumnalis, 10 cows were seropositive, whereas with L. hebdomadis 22 were seropositive; no cows were seropositive for L. icterohaemorrhagiae. The seroprevalence of leptospirosis among dairy cattle in the western district of Ibaraki Prefecture was estimated at 15% (with 95% confidence and an interval of 10-20%). None of the seropositive dairy cattle demonstrated clinical signs of leptospirosis. These results suggest that Leptospira infection may be widespread among dairy cattle in this district