Freqüência de aglutininas anti-Leptospira interrogans em eqüídeos, em Minas Gerais, 2003 a 2004 / Frequency of anti-Leptospira interrogans agglutinins in equidae in Minas Gerais, Brazil, from 2003 to 2004

The goal of this research was to find the frequency and spatial distribution of infection caused by Leptospira interrogans in equidae in Minas Gerais State from September 2003 to March 2004. Samples of blood serum (6,475) were analyzed by microscopic agglutination test. From the total, 381 samples were positive (5.9 percent), with title equal or superior to 1:200 for one or more serovars of leptospira. The most frequent serovars were Hardjo (Norma), Pomona, Bratislava, and Batavie. The higher frequency of equidae reagents were recorded at the North and Northeast region of Minas Gerais, followed by Triângulo Mineiro and Alto Paranaíba, then Central, West, Metropolitan area of Belo Horizonte, and South/Southwest.