Present-Day Epidemiological-Epizootological Peculiarities of Natural Tularemia Foci in Altai

RelevanceNatural tularemia foci are widespread in Altai Krai and Republic Altai and characterized by high functional stability.Aim.To study modern epidemiological and epizootological features of natural foci of tularemia in the Altai region Russia.Materials and MethodsThe current state of small mammal number in the region is examined. Results of complex studying of 14 Francisella tularensis strains isolated in Republic Altai from 1950 to 2015 (from the collection of Museum of live cultures in Irkutsk Antiplague Research Institute of Rospotrebnadzor) and 21 strains isolated in 2016–2018 in the Altai region are presented. For the first time the tularemia causative agent was isolated at this territory in 1940s. Water vole (Arvicola amphibius) is the most epidemiologically significant as the infection source in these foci. Ixodes ticks: Dermacentor silvarum, D. reticulatus, D. marginatus, Haemaphysalis concinna, Ixodes persulcatus are the main vectors. Now Francisella tularensis subspecies holarctica circulates at Altai territory, and since 2011 additionally F. tularensis mediasiatica.ConclusionsThe functioning of the natural center of tularemia in the territory of the Altai region in the modern period is characterized by coupled circulation of the causative agent of tularemia of two subspecies, sporadic cases of tularemia diseases and infection by the causative agent of environmental objects (bloodsucking arthropods, open water, small mammals). All this indicates a high activity of natural foci with respect to this especially dangerous natural focal infection.