Avaliação de uma microimunodifusão em gel de ágar para diagnóstico de lentivírus de pequenos ruminantes em caprinos

Abstract

Lentiviroses of Small Ruminants – SRLV (Caprine Arthritis-encephalithis-CAE and Maedi-Visna) affects goat and sheep. It is characterized by a slow and gradual course, where the majority of animals does not present symptoms, and sorology is the most practical mean of diagnosis, where the presence of antibodies demonstrates indirectly the existence of SRLV infection. The aim of this work was to evaluate an agar gel microimmunodifusion (micro- AGID) test in comparison with a macro- AGID test to be used in the serologic diagnosis of SRLV in goats, on the basis of relative sensitivity and specificity, as well as the Kappa index (k), calculated in accordance with the results of the tests. Calculus were performed according to results from 262 goat serum samples, from four properties, located in the Rio Grande do Norte (1), Pernambuco (2) and Paraíba (1). Results presented a relative sensitivity and specificity of 100% and a perfect agreement between the tests (K = 1,00). From the 262 goat sera evaluated trough macro-IDGA and micro-IDGA, 9,54% (25/262) presented a positive result and 90,46% (237/262) presented a negative result in both tests. Micro-IDGA presented clearer reactions to qualitative characteristics, such as precipitation line intensity, clarity and timing for detection when compared to macro-IDGA, at the reading performed after 24hours of incubation. No alterations were observed after 48h. It can be concluded that, Micro-IDGA may be able to substitute macro-IDGA in the serologic diagnostic of SRLV and that reading time, and results definition may be reduced to 48hours with no decrease in the confidence of results.