Features of the Incidence of Shigellosis in the Karachay-Cherkess Republic in 2005–2019

Abstract

Introduction: In the Karachay-Cherkess Republic (KCR), dysentery and salmonellosis rank high in the etiological structure of intestinal infections and arose interest in studying the incidence of shigellosis in the republic. Our objective was to analyze the incidence of bacillary dysentery, to study Shigella landscape in the territory of the KCR in 2005–2019, and to compare the findings with similar variables in other regions of the Russian Federation. Materials and methods: We analyzed data of the Center for Hygiene and Epidemiology in the Karachay-Cherkess Republic on the incidence of shigellosis and Shigella isolates obtained from human stool samples in the KCR in 2005–2019 and compared them with available results of similar studies conducted in other parts of the country. Results: When analyzing the curves of the incidence of dysentery in the KCR and the Russian Federation, we found that they were asynchronous. In the KCR, the curve rose twice (in 2005–2006 and 2011–2014), while in the Russian Federation, the incidence rates demonstrated a gradual decrease. Over the whole observation period, only in 2018–2019 the incidence of shigellosis in Karachay-Cherkessia was 1.3–1.8 times lower than in the country as a whole. We also established that, in contrast to the Russian Federation, Shigella sonnei represented by the biochemical variant IIg prevailed in the structure of shigellosis in the republic. The analysis of the relationship between the number of detected samples of dairy products of poor microbial quality and the incidence rate of Sonne dysentery showed that those two variables did not always correlate. Molecular genotyping of Shigella sonnei strains by pulsed-field gel electrophoresis (PFGE) allowed us to assume the imported nature of the pathogen. The import could have occurred during the Hajj to Mecca and Medina of KCR residents in 2012. Conclusion: Shigella sonnei strains differing in the presence of tetracycline and chloramphenicol (levomycetin) resistance determinants are circulating in Karachay-Cherkessia. No bacteria resistant to ciprofloxacin were isolated in the republic in 2005–2019.