Epidemiological Manifestations Ixodid Tick-Borne Borreliosies in Irkutsk and in other Parts of the Eurasian Area

Background. Ixodid tick-borne borrelioses (ITBB) is the most prevalent in Northern Hemisphere group of transmissible Spirochaetal infections, ecologically connected with Ixodid ticks. ITBB are etiologically associated with several agents, which determine epidemiological and clinical manifestations of these diseases. Research aim - the detection of ecological and epidemiological peculiarities of ITBB manifestations in the Baikal Region during the long-term period by comparison with that in the other parts of geographic range and the analysis of the manifestations dynamics. Material and methods. The database, developed by the authors, with information about ITBB cases in Irkutsk (1995-2017, n = 867) have been used in the work, and the similar studies in Russian and world literature have been reviewed. Statistical analysis was computed in Microsoft Excel Software. The map of infecting sites is made in ArcGis Soft (ESRI, USA). Results. The data have been analyzed on ecological and geographical (place and time of the infected tick bite), epidemiological (gender, age, localization of the tick bite, form of the disease), social and behavior (employment and circumstances of the infecting, including professional risk activities) signs. The interrelationship of some of them and their temporal evolution was studied. Similarities and differences of the ITBB manifestations in Baikal Region and other parts of the disease area have been revealed. The following peculiarities of ITBB in Baikal Region were found: 1) the average age of the patients is over 40; 2) a slightly higher number of males between the patients (57.3%); 3) increase (from several cases up to 40-47%) in the proportion of ITBB form without skin manifestations from the beginning to the end of the analyzed period; 4) the significant age difference between patients with and without skin manifestations (primarily persons over 50 and mainly the children respectively).