The occurrence of Borrelia miyamotoi in Dermacentor reticulatus and Ixodes ricinus ticks in the Chornobyl Exclusion Zone, Ukraine.

Borrelia miyamotoi spirochete is carried by Ixodidae ticks and causing Borrelia miyamotoi disease (BMD), a relapsing fever illness reported worldwide, often in the same geographic areas where Lyme disease is endemic. The purpose of this study was to examine the presence of B. miyamotoi infection in Dermacentor reticulatus and Ixodes ricinus ticks collected within the boundaries of the Chornobyl Exclusion Zone, Ukraine. A total of 1176 adult D. reticulatus ticks and 113 adult I. ricinus ticks sampled from five different habitats in the Chornobyl Exclusion Zone, Ukraine, were tested for Borrelia miyamotoi using a two-step nested PCR procedure. Borrelia miyamotoi was found in two (0.17%) out of the 1176 D. reticulatus ticks tested. The obtained sequences were submitted to GenBank (MZ365312-MZ365313). Phylogenetic analysis showed that the B. miyamotoi sequences detected cluster together with a strain originating from I. scapularis in the USA. The strain identified in the Chornobyl Exclusion Zone belongs to the group of strains found in Eastern Europe and Asia, north of the Himalayas. No I. ricinus ticks were found to be infected. This study presents the first detection of B. miyamotoi in D. reticulatus ticks in the Chornobyl Exclusion Zone, Ukraine.