DETECTION OF SHEEP-ASSOCIATED MALIGNANT CATARRHAL FEVER VIRUS-ANTIBODIES BY COMPLEMENT-FIXATION TESTS

Some serological diagnosis methods and examinations for detection of a ntibodies to sheep-associated malignant catarrhal fever (MCF) infectio n were investigated. The wildebeest-associated MCF virus strain WC11 p ropagated on fetal bovine thyroid cell cultures was used as an antigen . Antibodies were detected by complement fixation (CF) tests in cattle pathologically diagnosed as having sheep-associated MCF, as well as i n cattle experimentally infected with MCF virus strain WC11. However, immunodiffusion precipitation was only detected in cattle infected wit h MCF virus strain WC11. The results of serological investigation by C F tests indicated that 64.3% of sheep possessed antibodies to MCF viru s in the Hokkaido district of Japan and all serum samples which contai ned CF antibody titers greater than 1:4 had antibody titers larger tha n 1:8 in indirect immunofluorescence tests. The CF test we demonstrate d here is available to quantitatively detect MCF virus antibody titers in epidemiological surveys.