STUDIES ON TICKS OF THE GENUS DERMACENTOR (ACARI; IXODIDAE) TO NATURAL OCCURENCE CAUSE OF Q FEVER UNDER CONDITIONS CENTRAL CAUCASIAN REGION

The purpose of the research: to assess the natural occurrence of Coxiella burnetii in ticks of the genus Dermacentor; clarify of the relationship between the physiological age of ticks and their infection with the Q fever patogen. Materials and methods: In the period from 2017 to 2019, we examined 4908 specimens of Dermacentor marginatus (616 pools) 4208 specimens of Dermacentor reticulatus (566 pools) and 43 specimens of Dermacentor niveus (18 pools) were examined for infection with the Q fever patogen. To assess the dependence of the detection of Coxiella burnetii in ticks depending on the physiological age, we examined 3048 specimens D. reticulatus (381 pools) and 2319 specimens D. marginatus (366 pools). The study of ixodid ticks for the presence of Coxiella burnetii DNA of the causative agent of Q fever was carried out by the molecular genetic method, namely the polymerase chain reaction (PCR), in accordance with the regulatory guidelines. Results and discussion: The results of the research showed that the infection of ixodid ticks with Coxiella in the Central Ciscaucasian natural populations on D. reticulatus and D. marginatus fluctuates over the years and does not exceed one percent. When considering the dependence of the detection of Coxiella burnetii in ticks on their physiological age, statistically significant results were obtained only for D. reticulatus. There is a significant correlation between the more frequent detection of infected ticks of physiological age II compared with ticks of physiological age III and IV. For D. marginatus ticks, there was no statistically significant relationship between the detection of Q fever pathogen and physiological age. Key words: ixodid ticks, Dermacentor reticulatus, Dermacentor marginatus, Dermacentor niveus, Q fever, physiological age.