Experiences on diagnosis and isolation of Trypanosoma evansi infection in cattle in field condition

摘要

Two chronically infected cattle suspected for Trypanosoma evansi infection were studied for confirmative diagnosis and isolation of parasites. One zebu cattle with symptoms of intermittent rise of temperature (38.3 degrees C to 41.1 degrees C), bottle jaw and chronic emaciation, found positive for T. evansi in Giemsa stained blood smears, but found negative for T evansi after mouse inoculation test (MIT). Other crossbred cattle with symptoms of intermittent rise of temperature (38.3 degrees C to 41.7 degrees C) and decreased milk yield, found negative for T. evansi infection in Giemsa stained blood smears, but found positive after repetition of MIT. In such MIT only 25% inoculated mice of batch showed positivity in MIT. The presence of anti-T evansi antibody was detected in serum samples of both of these cattle, as observed in indirect ELISA test. It has been concluded that cattle positive for T. evansi infection in blood smears may not always positive in MIT and negative in blood smears for T. evansi, may be positive in MIT, which may need repeated inoculation of suspected blood to mice in different time intervals and in different batches to get positive result in MIT, in field condition. Repetition of MIT for successful result for isolation of T evansi in field condition is reported.