Challenges in the diagnosis of coxiellosis and the perspectives of personalized treatment

Yankovskaya Ya.D., Chekanova T.A., Kutateladze M.V., Petremgvdlishvili K., Chernobrovkina T.Yа., Skryabina A.A.

Pirogov Russian National Research Medical University, Moscow
Central Research Institute of Epidemiology, Moscow

The aim of this work is to evaluate the occurrence of serological markers of Q fever (coxiellosis) in a group of patients who sought medical help at the Moscow Infectious Diseases Clinical Hospital, and to describe, using clinical examples, the features of the course and the complexity of diagnosing acute and chronic forms of the disease to justify the choice of personalized treatment.
Material and methods: Using enzyme immunoassay (ELISA) and polymerase chain reaction (PCR) methods, plasma/serum samples of 111 patients were studied, in whom the fact of tick bite was known in history and/or according to clinical and epidemiological data, fever and other signs were present. disorders of general well-being and organopathology.
Results: in the acute form and in the chronic course of coxiellosis, laboratory diagnostics using an isolated method of polymerase chain reaction in the blood does not always make it possible to identify the causative agent of the alleged infectious disease, which may be associated with delayed sampling of material for research and a decrease in bacteremia in the blood, including due to previously started antibiotic therapy of patients, and allows only to preliminarily exclude the acute phase of Q fever. Clarification of the diagnosis was achieved by additional analysis by ELISA with the identification of qualitative and quantitative characteristics of immunoglobulins IgM and IgG to the antigens of the pathogen (C. burnetii). The given clinical examples demonstrate the difficulties of verifying the diagnosis of acute and chronic forms of Q fever in practical medicine and overcoming them by means of complex PCR + ELISA diagnostic studies.
Conclusion: The results of this study indicate the need to include in the protocol for managing patients with suspected tick-borne infections a complex of laboratory tests for the presence of specific markers of Q fever (detection of the pathogen and antibodies to it). In addition, to reduce the risk of developing a chronic form of coxiellosis, long-term monitoring of the dynamics of antibody titers to C. burnetii is recommended, differentiated taking into account phases I and II of the pathogen and the immunological response of the body.