Padronização de um teste de soroaglutinação macroscópica para diagnóstico da leptospirose em suínos

Abstract

Leptospirosis is considered a global health problem in human and veterinary medicine. It is a zoonotic disease caused by bacteria of the genus Leptospira, prevalent on every continent. The development of an effective macroscopic serum agglutination test against leptospirosis is justified, since the available ones are expensive, cumbersome and restricted to specialized laboratories. In Brazil, leptospirosis in pigs has been a major cause of reproductive failure in several states, mainly in the south and southeast regions of the country. Among the animals used in production of rural ecosystems, pigs have the most frequent clinical manifestations in the reproductive sphere with abortions, usually in the final third of pregnancy. Infertility, sterility or birth of debilitated or dead pigs which dies in the first days of life are signs of the presence of the bacteria in the breeding matrix. In the present study, six suspensions formulations of antigenic serovars pomona, icterohaemorrhagiae and copenhageni were used in single suspension form or in two serovars combinations. These were tested against pig serum with no clinical suspicion of leptospirosis compared with the microscopic agglutination test that is accepted as the gold standard by the World Health Organization (WHO). Among the six proposed suspensions the combination of serovars pomona + icterohaemorrhagiae showed the best result. The results demonstrates a percentage of 89% sensitivity and specificity of 89% for the suspension with the serovars combination of pomona + icterohaemorrhagiae and 87% for positive predictive value and 90% negative predictive value for the same combination, demonstrated by the statistics methods such as Chi-square, Kappa and Linear Logistic Model. Given the importance of leptospirosis in pigs and economic impact that it causes worldwide, in addition to the lack of current information, this study aimed to develop a screening rapid test for the diagnosis of pigs kept in variable dimension farms from rural regions of the Rio de Janeiro state.