Ecological and epizootological characteristics and laboratory diagnostics of Q-fever in cattle on the materials of Omsk region

In order to improve the laboratory diagnosis and assessment of the epizootic situation of the bovine Q fever, the animal immunization schemes for obtaining hyperimmune sera and methods for sensitizing red blood cells have been improved, on the basis of which the Coxiella antigenic erythrocyte diagnosticum for the indirect hemagglutination reaction and hyperimmune sera for the indirect immunofluorescence reaction were developed and tested. Approbation of methods was carried out in the farms of the Omsk region. The method used to prepare the Coxiella antiserum with the help of the Coxiella antigen from the Coxiella burnetii strain M-44 was used, by the hyperimmunization of rabbits according to the D. Schimmel scheme in our modification with additional subcutaneous administration of the immunostimulant levamisole with the first two intravenous injections of the antigen. Also, a co-eagle antigenic erythrocyte diagnosticum was constructed for the reaction of indirect haemagglutination. The diagnostic was prepared according to the Fili method in our modification, which consists in a more gentle method of exposing formalin to erythrocytes and at the same time ensuring their good fixation. As a sensitin, the Coxiella antigen was also used from the strain Coxiella burnetii M-44. The obtained diagnosticum whey possess specificity, high sensitivity and activity and not only is not inferior to the standard luminescent anti-Coxiella serum, but also allows to identify more animals in the indirect version of fluorescent antibodies with a low concentration of antigen in titres 1 : 32-1 : 64. The developed antigenic erythrocyte diagnosticum is specific and has sufficient activity in the RNGA with fever of the Ku of cattle. It can be used to detect antibodies to Coxiella in the blood serum of sick cattle and carriers. The epizootic state of livestock farms for the Q fever of cattle is estimated in many years of dynamics. The results of the conducted studies testify to the wide spread of the Q fever of cattle in the Omsk region in the modern period, despite the absence of official registration of this infection. Given the long-term disadvantage of farms in the region for the Q fever of cattle, it is necessary to introduce an effective system of epizootic-epidemiological surveillance and measures to combat this infection at the federal and regional levels.