Acta Biomedica Scientifica (Jul 2025)
New data on infection of <i>Haemaphysalis concinna</i> with tick-borne infection agents in humans and animals in the territory of Baikal region
Abstract
Background. In recent years, the tick Haemaphysalis concinna has drawn increased attention from researchers due to its expanding geographic range and its growing role in the transmission of diseases of various etiologies to humans and animals. However, studies on the infection of H. concinna with tick-borne pathogens affecting humans and animals in the Baikal region have been minimal, despite its known capacity to carry at least 40 pathogen species pathogenic to humans. The aim. To investigate the infection of Haemaphysalis concinna with tick-borne pathogens affecting humans and animals in the Baikal region. Materials and Methods. A total of 998 specimens of H. concinna ticks collected from natural habitats in the Baikal region were analyzed by PCR for the presence of markers of various viral, bacterial, and protozoan pathogens. Results. In the examined H. concinna ticks, the following pathogens were detected: Kemerovo virus RNA (1.1 %), Borrelia burgdorferi sensu lato (1.3 %), Borrelia miyamotoi (0.5 %), Ehrlichia sp. / Anaplasma sp. (3.7 %), Rickettsia sibirica (1.6 %), Rickettsia raoultii (2.8 %), «Candidatus R. tarasevichiae» (32.6 %) and Babesia spр. (3.5 %). Tickborne encephalitis virus (TBEV) RNA was not detected in this study; however, in earlier PCR-based investigations, TBEV RNA was found in 0.6 ± 0.6 % of H. concinna samples from the Baikal region. In one tick sample, the nucleotide sequence of the groESL operon (1315 bp) was identified and found to be identical to sequences of Ehrlichia muris. Based on 18S rRNA gene sequence analysis, Babesia species genetically close to small ruminant piroplasms – Babesia crassa and Babesia motasi – were identified. For the first time, a Babesia sp. DNA sample was detected with nucleotide sequences identical to the Kh-Hc222 strain (KJ486568), previously identified in Khabarovsk Krai. Conclusion. The data obtained underscore the need for continuous monitoring of H. concinna tick populations in the Baikal region and further investigation into their infection with both well-known and newly identified vector-borne pathogens.
Keywords
