Clinical and epidemiological characteristic of chronic brucellosis

Aim. To study clinical epidemiological and laboratory features of chronic brucellosis in the Republic of Tatarstan in ten-year aspect. Methods. 59 patients infected with various forms of brucellosis in 2007-2017 were examined. Clinical laboratory and instrumental diagnosis of brucellosis was confirmed by the immunoassay (EIA) with determination of IgM and IgG antibodies, passive hemagglutination test with a brucellar diagnosticum, Coombs test, Wright and Hedelson agglutination test. Results. Clinically 91 % of patients had asthenic-vegetative syndrome, 55 % - mild intoxication symptoms, 89 % - articular syndrome, 49 % - fibrositis. EIA revealed in 91 % of patients IgG (38 %) and IgM (53 %) antibodies to causative agents of brucellosis, 25 % of patients had positive Wright agglutination test, and 30 % - positive Hedelson agglutination test. In 9 % of cases the diagnosis was confirmed by Coombs test and in 26 % by passive hemagglutination test with brucellar diagnosticum. The retrospective analysis with clinical cases of patients with chronic brucellosis indicates introduced cases in 19 % (from the republics of Central Asia and Transcaucasia), local cases in 81 % (from the Republic of Tatarstan), their occupational character (57 %), the mixed (contact and alimentary) route of infection (21 %), and 64 % with clinically primary involvement of the musculoskeletal system and peripheral nervous system, i.e. prevalence of the mixed form of chronic brucellosis. Conclusion. Chronic brucellosis in the Republic of Tatarstan is characterized by high risk of introduced cases, occupational history, prevalence of the mixed route of infection in females and working-age patients; with the features of systemic disease involving the musculoskeletal and peripheral nervous system against the background of mild syndrome of intoxication and moderate asthenic-vegetative syndrome. Divergence of the results of serological diagnostics requires careful studying of duration of infection, features of the immune response in each case on follow-up.