Analyzying the documented results by using microscopic agglutination test to examine sera from patients suspected of leptospirosis

Leptospirosis holds one of the leading places among zoonoses due to the breadth of distribution of natural and economic foci, as well as the severity of the clinical manifestation and mortality rate. A relatively low incidence rate in some regions is usually accounted for by unsatisfactory level of differential diagnostics, including insufficient coverage by diagnostic tests. Leptospira are characterized by marked phenotypic and genotypic polymorphisms, affecting epidemiological features and clinical manifestation of leptospirosis. Therefore, laboratory methods are important tool for epidemiological surveillance and diagnostics of leptospirosis. Serological methods primarily the microscopic agglutination test (MAT) currently remain the leading tool in investigating leptospirosis. To study a near 60 year-long contribution of various leptospira serogroups to etiological pattern of leptospirosis, we have analyzed archived MAT serum data from patients suspected of leptospirosis retrieved from our laboratory journals during from the years 1962 to 2020. It was shown that antibodies to the Grippotyphosa serogroup (25.1%) were found most often in patients, which might be associated with the wide range of reservoir host animals and resistance of this leptospira serogroup to environmental factors. At the same time, it should be noted that at different periods antibodies to various leptospira serogroups prevailed in the sera of patients, and in many cases this data matched with the contribution of these pathogens to the etiological morbidity pattern. In particular, dominance of pathogens of the Sejroe serogroup is currently the global trend in the etiological pattern of leptospirosis that was also observed by us at some years. The data obtained might be useful for epidemiological surveillance of leptospirosis infection, including predicting potential outbreaks, as well as for developing approaches to its diagnostics, treatment and prevention.