[Demonstration of the infectious rhinotracheitis-pustular vuluovaginitis virus (IBR-IPV) in the placenta and aborted fetuses of cows].

A well expressed correlation was found to exist between the immunofluorescence and the histologic methods in the demonstration of IBR-IPV infection of fetuses and placentae in 75 cases of spontaneous undiagnosed abortions. If those that were positive by the immunofluorescence method were 100 per cent as many as 87 per cent of them showed coincidence with the results obtained by the histologic method. The isolation of the virus of IBR-IPV coincided in 44 per cent of the cases only. Clearest specific fluorescence, established most frequently, was demonstrated in the kidneys of the fetuses. It was found that contrast staining with Evans blue effectively inhibited the unspecific fluorescence. Exceptions in this respect were observed with some preparations of liver, lung, and placental tissues, where there were cells of unspecific fluorescence, which, by its character and localization differed essentially from the fluorescence that was specific for IBR-IPV. It is assumed that the immunofluorescence method performed at contrast staining with Evans blue makes possible the fast and precise diagnosis of IBR-IPV.