ABSTRACT
For the first time, a comparative description of clinical and laboratory parameters in patients with clinical signs of tick-borne rickettsiosis in a natural focus with a low risk of infection with R. sibirica and circulation of R. raoultii is given, depending on the results of serological verification of the diagnosis. Established almost complete coincidence of clinical and laboratory parameters in patients with tick-borne rickettsiosis, regardless of the presence of antibodies to R. sibirica and / or R. raoultii. It was shown that even the complex use of complement fixation test, indirect immunofluorescent test and ELISA for the detection of antibodies to R. sibirica does not allow verification of the diagnosis in a third part of patients with pathognomonic signs of tickborne rickettsiosis. In seropostive patients, antibodies to R. sibirica prevailed, which makes it impossible to differentiate cases of tick-borne rickettsiosis of different species etiology. The possible reasons of the phenomenon of «seronegativeness¼ of patients with tick-borne rickettsiosis and approaches to its study are discussed. It is concluded that with the existing diversity and insufficient knowledge of rickettsiae circulating in natural foci, and the current state of laboratory diagnostics, the basis for the diagnosis of «Tick-borne rickettsiosis¼ should be the clinical and epidemiological signs of this infectious disease, which must be recorded in the established order even no serological verification. For such cases, ICD-10 has two encoding options: A 79.9 - Rickettsiosis, unspecified (infection caused by rickettsia, no other indication) and A 77.9 - Spotted fever, unspecified (tick-borne fever, no other indication) [mkb-10.com].
