ABSTRACT
Ixodes ticks are known as carriers of pathogens of many infectious diseases with natural foci. 12 species of Ixodes ticks carrying the virus of Crimean-Congo hemorrhagic fever and lumpy skin disease (dermatitis nodulares) of cattle were found in the foothill zone of Kabardino-Balkaria. In the Republic of Dagestan, Hyalomma. p. plumbeum ticks are the carriers of pathogens of taileriosis of cattle (13.6%), and the incidence of animals is 24.4%. In the Kaluga region, infection with I. ricinus Borrelia reaches 16.9%, and with Dermacentor reticulatus it is at 12.3%. In the Omsk region, mixed infection with pathogens of infectious diseases with natural foci was found in 16.5% of Ixodes ticks. In the south of Eastern Siberia, the infection rate of taiga ticks with tick-borne encephalitis virus ranged from 0.5 to 4.5%, and on average it was about 1.2%. Infection of taiga ticks with Borrelia ranges from 10 to 34%, on average reaching 19%, of which 2.5% cases are with a high degree of infection. In Khabarovsk, 18.3% of ticks were infected with Borrelia, and the tick-borne encephalitis virus was found in 2.4% of ticks. In the south of Primorsky Krai, 13.3% of Ixodes persulcatus ticks have pathogens of viral and bacterial infections. In the Republic of Sakha (Yakutia), the virulence of ticks was 5.7 - 9.8%. The biological type of tick development does not change the fundamental side of brucella reservation and transmission of infection to healthy animals.