EVALUATION OF MODERN EPIZOOTIC ACTIVITY OF NATURAL TULAREMIA FOCI IN VORONEZH REGION USING IMMUNE-SEROLOGICAL AND MOLECULAR-GENETIC STUDY OF MAIN CARRIERS OF THE DISEASE

Abstract

Aim. Improvement of monitoring and prognosis of epidemic manifestations of natural foci of tularemia on the territory of Voronezh region using immune-serological and molecular-genetic study of main carriers of the disease. Materials and methods. 539 small mammals captured during summer period of 2011 in 4 districts ofNorth-Eastern part ofVoronezh region were studied. Animal organs were studied by serologic (search for Francisella tularensis antigens) and molecular-biologic (detection of F. tularensis DNA) methods. Tularemia antigen was detected using passive hemagglutination reaction (PHAR) with erythrocytic tularemia immunoglobulin diagnosticum. Real-time polymerase chain reaction (RT-PCR) was applied for detection of tularemia causative agent DNA. Results. Complex study revealed epizootic activity of natural foci of tularemia in the examined territory. F. tularensis antigen and/or DNA were detected in 82 objects (15.2%). Use of RT-PCR allowed to additionally detect samples with relatively low content of F. tularensis DNA substrate, when antigen was not detected in samples. High sensitivity and specificity of the RT-PCR was ensured by inclusion of specific probes (tul4-PR2 and ISFTu2P). Conclusion. The results obtained give evidence on functioning and epizootic activity of natural foci of tularemia in Voronezh region that requires constant monitoring of the territory and prophylaxis measures, first of all vaccination of risk groups by live tularemia vaccine.

Keywords

• natural foci oftularemia
• small mammals
• passive hemagglutination reaction
• real-time polymerase chain reaction
• epizootologic monitoring
• prophylaxis