Aglutininas antileptospira em soros de bovinos do Estado do Rio de Janeiro

Bovines sera (1,562) from 28 municipalities of the State of Rio de Janeiro were examined by the microscopic agglutination test with 17 live antigens of leptospiras. Positive reactions with titres starting at 1:100 were observed in 21,85% of the sera, consisting mainly of serotypes wolffi, tarassovi, grippotyphosa, pomona, bratislava and strain Mn-2. The highest titres were found with strain Mm-2 (1:102,400) and the serotypes wolffi (1:12,800) and pomona (1:3,200). Co-agglutinations were also observed. Cows with positive agglutination reactions were observed in 54 of 64 farms studied (84,37%). Homogenic micro-region and altitude affected the prevalence of reactivity in animals, and an increased rate of positive reactions occurred up to an altitude of 400 m. The municipalities of Cabo Frio, Miracema, Nova Iguacu and Macae had highest prevalence of positive reactions. The use of pooled sera in the screening of the positive animals was very useful, as it afforded an economy in time and material.