Prevalence of Leptospiral Antibodies in Dairy Cows in Japan

Abstract

The prevalence of leptospiral antibodies in dairy cows was investigated throughout Japan. The antibodies were detected by an ELISA screening test using individual bulk tank milk and a microscopic agglutination test (MAT) using serum. A total of 249 dairy farms were randomly selected for the survey, with 78 (31.3%) of the farms found to be positive for Leptospira interrogans serovar Hardjo. Of 1,510 cows randomly selected from the farms that were found to be positive in the ELISA test, 688 (45.6%) were positive for leptospiral antibodies, with the positive rate in Hokkaido (67.5%) being particularly high. The positive rate for L. interrogans serovar Hardjo was the next highest, detected in 663 cows (43.9%), followed by L. interrogans serovar Hebdomadis (38.9%). In the detection of antibodies from serum using the ELISA test, 723 (47.9%) of cows were found positive for serovar Hardjo, which corresponded well with the MAT results. Thus, the wide prevalence of leptospiral antibodies in dairy cows in Japan was confirmed using the MAT and ELISA tests, and L. interrogans serovar Hardjo was found to be the major serovar.