Yurchenko O. Transmissible viral infections of the Northwest Black Sea Coast

Research object: the circulation of arboviruses - pathogens of transmissible especially dangerous natural focal human diseases in the Northwest Black Sea Coast. Aim: to establish the prevalence of arboviruses in natural foci and among people and to optimize laboratory diagnostics of transmissible viral infections. Methods: virological, molecular-genetic (RT-PCR, sequencing), serological (ELISA), descriptive-evaluative, analytical and statistical. Theoretical and practical results: high activity of natural foci of tick-borne encephalitis, West Nile fever, Sindbis, and Ukuniemi viruses and moderate - of Crimean-Congo hemorrhagic fever, Inkoo, Tahyna, and snowshoe hare viruses was shown; species composition of the vectors and reservoirs of arboviruses was determined. Range of arboviruses circulating in the human population was determined, etiological role of West Nile and tick-borne encephalitis viruses in the regional infectious pathology was confirmed, human infection with Sindbis, Tahyna, and snowshoe hare viruses were detemined. The envelope (E) protein gene of 7 tick-borne encephalitis virus strains was sequenced, belonging of the studied strains to the European (Western) genotype of the virus was proved, their unique separate phylogenetic position with the highest relationship to Pan strain and the presence of 4 marker amino acid replacements was established. The circulation in the region of 2 genotypes of virus explains polymorphism of clinical manifestations of tick-borne encephalitis in humans. The efficacy evaluation of virological, serological and molecular-genetic methods for the indication of arboviruses in the environment and for examination of patients with suspected arbovirus diseases was carried out. Staging of serological monitoring of arbovirus infections in people was determined and grounded, suitability of using molecular-genetic techniques for indication and differentiation of arboviruses in the environment was demonstrated. Determination of the basic and additional species of vectors will allow optimizing the stage of catching and volume of laboratory studies of the environmental objects during epizootological monitoring. Scientific novelty: for the first time the complex laboratory testing of samples from humans and biotic objects of environment was carried out and the structure and activity of natural foci of arbovirus infections was determined. For the first time in Ukraine the sequencing genome fragment of the tick-borne encephalitis virus were conducted and the circulation European (Western) genotype of tick-borne encephalitis virus was proved. Level of inculcation: the results obtained were implemented into the practical work of sanitary-epidemiological service of the 4 regions. Sphere of application: medicine, biology.