Ticks and tick-borne infections in Karelia: analysis of ticks brought by citizens to be tested at the Center for hygiene and epidemiology in the Republic of Karelia (Petrozavodsk)

In 2019 and 2021, species composition of the ticks provided by citizens was studied at the Center for Hygiene and Epidemiology in the Republic of Karelia (based in Petrozavodsk). As a result, about 2 500 tick specimens were identified as belonging to the following species of the family Ixodidae: Ixodes persulcatus Schulze, 1930, I. ricinus (Linnaeus, 1758), Dermacentor marginatu s (Sulzer, 1776), D. reticulatus Fabricius, 1794, Hyalomma marginatum Koch, 1844, and Rhipicephalus sanguineus (Latreille, 1806). For 2% of the ticks, including all species not typically dwelling in Karelia, the attacks occurred outside of Karelia. For districts of Karelia, two species were identified: I. persulca tus (approx. 95% of all ticks delivered) and I. ricinus . Prevalence of pathogens in ticks as analyzed with the use of a commercial kit «AmpliSense® TBEV, B . burgdorferi sl, A . phagocytphillum , E . chaffeensis / E . muris - FL» based on real-time PCR. Prevalence of the tick-borne encephalitis virus in I. persulcatus was 1.5%. In I. ricinus ticks the virus was absent. The prevalence of the Borrelia burgdorferi s. l. and Ehrlichia spp. complex constituted 32.5 and 3.3% in I. persulcatus versus 16.3 and 0.8% in I. ricinus , respectively. A single occurrence of Anaplasma phagocytophillum was found in I. persulcatus (prevalence - 0.04%). The main determinant of the epidemiological situation in Karelia is the wide distribution and high abundance of I. persulcatus .