[Immunofluorescent test in the diagnosis of babesiasis]

The direct and the indirect immunofluorescence methods were tested in the diagnosis of babesiasis in sheep. The antigen used was material of erythrocyte smears with Babesia ovis, and the conjugate employed in the direct method was obtained from a hyperimmune anti-Babesia ovis serum labelled with fluorescein-isothiocyanate. For the indirect methods rabbit anti-sheep globulin was made of, labelled with the same fluorochrome. The specificity of the direct methods was demonstrated by the absence of fluorescence in the control smears with Th. ovis, A. ovis and E. ovis at a 1:20 dilution of the conjugate (and even in higher dilutions), while that of the indirect methods--by the absence of fluorescence with the control negative serum and the heterologous antisera at the same values of dilution. The comparative testing of the indirect immunofluorescence methods and the complement-fixation reaction in the periodic investigation of 10 lambs (experimentally infected) and 10 sheep (naturally infected) with Babesia ovis revealed that the indirect methods were of higher infected) with Babesia ovis revealed that the indirect methods were of higher sensitivity. This, and the easier production of the antigen gave grounds to assume that indirect methods are more readily applicable in the laboratory diagnostic practice. On the other hand, direct methods are more accurate in the species differentiation of the Babesia agents.