A total of 403 buffaloes serum samples from seven counties of Vale do Ribeira, São Paulo State, Brazil, obtained between January 1992 and June 1993, were studied to determine the prevalence of anti-leptospire agglutinins using the microscopic serum agglutination test. A titre of 100 and above was considered positive. The highest titre found was 1600 to the sorovar bratislava (one sample), followed by 800 to wolffi (4 samples). 152 (37.7%) samples from the total were positive to the serovars tested, and their prevalence, in decreasing order, was: wolffi (68, 44.8%), icterohaemorrhagiae (51, 33.6%), hardjo (51, 33.6%), castellonis (25, 16.5%), djasiman (12, 7.9%), grippotyphosa (10, 6.6%), pomona (8, 5.2%), bratislava (6, 4.0%), copenhageni (5, 3.3%) and tarassovi (4, 2.7%).
leptospira; microscopic serum agglutination; buffaloes
