Infection of ixodes ticks and wild small mammals with pathogens of natural focal infections in the territory of the Kurortny district of St. Petersburg

The purpose of this study was to identify the genetic markers of Borrelia burgdorferi sensu lato, Rickettsia spp. SFG, Anaplasma phagocytophilum, Ehrlichia caffeensis/E. muris, Coxiella burnetii, and tick-borne encephalitis virus (TBE) in ixodes ticks and organs of wild small mammals collected and captured in 2020-2023 in the Kurortny district of St. Petersburg.Materials and methods. Samples of ixodes ticks and organs of wild small mammals were examined by real-time PCR for the presence of genetic material of the causative agents of tick-borne infections. Ixodes ticks were collected and wild small mammals were captured in the Kurortny district of St.Petersburg in the period 2020-2023. The study was conducted using commercial test systems.Results. The overall infection rates of ixodes ticks and wild small mammals in relation to B. burgdorferi s.l. were 23.7% and 5.2%, respectively; Rickettsia spp. SFG – 11.5% and 0.9%; E. chaffensis/ E. muris – 4.0% and 0.0%; A. phagocytophilum – 1.6% and 0.6%; C. burnetii – 3.3% and 5.2%; tick–borne encephalitis virus – 0.2% and 0.0%. The total infection rate of ticks with two or more pathogens was 6.6%, the most common combinations of mixed infections were: B. burgdorferi s.l. + Rickettsia spp. SFG, B. burgdorferi s.l. + C. burnetii and B. burgdorferi s.l. + E. chaffensis/ E. muris.Conclusion. The results obtained indicate the existence of active natural foci of tick-borne infections in the Kurortny district of St. Petersburg and substantiate the expediency of continuous entomological and zoological monitoring and improvement of preventive measures against tick-borne infections.