Verification of mono- and mixed contaminations transmitting agents tick-borne infections.

In the territory of the Primorsky region, the nosoareas of causative agents of tick-borne infections often coincide and lead to mixed infection of ticks, which causes the mixed pathology in humans . We investigated ixodid ticks taken from people during the epidemic season of 2019 for the spectrum of pathogens of transmissible infections to determine the degree of their mono- and mixed infection. 651 specimens of ixodid ticks investigated. RNA/DNA pathogens was determined by the method of polymerase chain reaction (PCR), TBEV antigen by ELISA. The presence in ticks of pathogens of the following diseases was detected: Lyme borreliosis (35.3%), tick-borne replasing fever (11.3%), human granulocytic anaplasmosis (2.6%), human monocytic ehrlichiosis (2.4%), tick-borne encephalitis (1.8%), tick-borne ricketsiosis (1.0%). As agents of mono-infections, the virus of TBE, ehrlichia, anaplasma and rickettsia in ticks occurred less frequently than in combination with other pathogens. A high frequency of occurrence B. burgdorferi s.l. in mono-infection detected (58.7%). B. miyamotoi has met evenly at ticks with mono- and mixed infections. Total mixed infection of ticks was 23.1%. Borrelia have been identified in all mixed cases. Variants of double combinations (95.5 % of cases from all mixed infections) were as follows: B. burgdorferi s. l. + A. phagocytophilum, B. burgdorferi s.l. + E. chaffeensis / E. muris, B. burgdorferi s.l. + TBEV, B. burgdorferi s.l. + R. heilongjiangensis, B. burgdorferi s.l. + B. miyamotoi. The most frequent combination was B. burgdorferi s.l. + B. miyamotoi (37.8% of all mixed infections). In triple infection of B. burgdorferi s.l. + A. phagocytophilum + TBEV and B. burgdorferi s.l. + A. phagocytophilum + B. miyamotoi, the frequency of occurrence for each combination was 2.2%. Given the above, a complex laboratory diagnosis of tick-borne infections in individuals who have been bitten by a tick is necessary, including the detection of all pathogens common in focal areas.