Capligina et al.
Large-scale countrywide screening for tick-borne pathogens in field-collected ticks in Latvia during 2017-2019
Parasit Vectors 2020, 13:351
A large-scale flagging of ticks and screening for pathogens have been carried out in Latvia from 2017 to 2019. In total, 4593 ticks were collected from 189 locations in various habitats. Ixodes ricinus was present across the whole country, while I. persulcatus was restricted to the northern and eastern regions, and Dermacentor reticulatus was found in southern, central, and western parts of Latvia. Thus, in some regions, two or three tick species are sympatric in this country. About a third of I. ricinus and I. persulacatus carried at least one pathogen and about a quarter of D. reticulatus. In total, 15 pathogens could be identified in ticks in Latvia, among which were several species of Borrelia, Rickettsia, Babesia and Anaplasma. More than 5% of the ticks were co-infected with at least two pathogens.
TBE virus was detected in nearly identical proportion of I. ricinus, I. persulcatus and D. reticulatus (around 0.65%). TBE virus positive ticks were mostly found in the western part of Latvia (Kurzeme region), from where most TBE cases are reported (incidence: 19.3 cases per 100,000) The authors concluded that all three tick species may be involved in the circulation of the virus in Latvia.