Objective of research: To study the spread of causative agents of babesiosis in ticks collected on the territory of the Kirov region with the use of molecular-genetic methods. Materials and methods: In this paper, the method of molecular-genetic detection of genetic material of the pathogen in the sample was used (the method of polymerase chain reaction (PCR). Ticks were collected from vegetation cover as well as from people and domestic animals (dogs, cats). Ticks were estimated according to identification tables. Causative agents of babesiosis were determined by the extraction of total nucleic acids from each tick; all ticks were examined using PCR. Total DNA extraction from ticks stored in 70% ethyl alcohol was performed with the use of guanidine thiocyanate. The proportion of ticks infected with Babesia was determined depending on the year, collection area on the territory of the Kirov region, species and sexual belonging of ticks. Results and discussion: It was found that the major tick vectors of Babesia on the territory of the Kirov region are ticks Ixodes persulcatus . In addition, two other tick species Dermacentor reticulatus and I. ricinus were detected in that region. It was shown, that the rate of Babesia infection in ticks Ixodes persulcatus was higher than in D. reticulatus and I. ricinus . The average percentage of ticks infected with Babesia was 53,07 %. A gradual increase of percentage of infected individuals with the maximum value 73,2 % was registered in 2012. However, in the following year, a significant decrease (51,7 %) was reported, and the minimum number of ticks infected with Babesia was observed in 2014 (37,4 %). A significant increase in infestation of ticks was newly observed in 2015 (50,4 %). It was found that male and female ticks are equally likely to be vectors for Babesia. Infection rates in male and female ticks were 54,5 and 49,3 %, respectively. Fluctuations in the number of infected ticks depending on the year (maximum in 2012 and minimum in 2014) were determined. Ticks from South-West districts of the region are mostly infected with Babesia. In the city of Kirov, 55,8 % of ticks are infected with Babesia in spite of acaricide treatment
