Comparison between specific immunoperoxidase staining and bacteriological culture in the diagnosis of renal leptospirosis of pigs

Seventy-two pigs were examined for the presence of leptospires in the kidney by both bacteriological culture and an immunoperoxidase procedure performed on formalin-fixed, paraffin-embedded sections of tissue with a primary antibody raised in rabbits against serovar pomona. The methods were in accordance in 62 of 70 (89 per cent) of the specimens. Compared with culture the sensitivity of the immunoperoxidase procedure was 30 of 38 (78 per cent) and its specificity 100 per cent; the predictive value of a positive result was 100 per cent, of a negative result, 80 per cent. The major advantages of the immunoperoxidase procedure are specificity, speed of execution and the possibility of simultaneous visualisation of leptospiral antigen and microscopic lesion.