Characteristics of the Epidemiological Situation on Cholera in the World and in the Russian Federation in 2020 and Forecast for 2021
Aim of the work - to assess the epidemiological situation on cholera in 2020 and to make a forecast for 2021 based on the monitoring data and analysis of morbidity around the world for the period of 2011-2020. During the period between 2011 and 2020, 4 413 988 cases of cholera were recorded in 97 countries of the world with a general trend towards a decrease in the incidence (coefficient of accuracy of approximation R2 - 0.5705). However, due to the continuing epidemic manifestations of cholera in the endemic countries of Asia, Africa and America, the epidemiological situation on cholera on these continents was characterized as unfavorable in 2020. The emergence of a new “post-Haitian” lineage was observed among epidemically hazardous strains of Vibrio cholerae O1. In 2020, no epidemically dangerous strains of V. cholerae O1, O139 were isolated from humans on the territory of the Russian Federation. 25 non-toxigenic V. cholerae O1 El Tor strains were isolated from environmental objects, eight out of which (ctxA-, tcpA+), according to PCR-INDEL typing and SNP analysis of sequences, belonged to the clonal complex. The results of the analysis of biological properties and phylogenetic relations between the isolated non-toxigenic strains provided the basis for considering the epidemiological situation on cholera in Russia in 2020 as a stable one and a similar forecast of its development in 2021. At the same time, the possibility of importation of this infection from endemic countries cannot be ruled out, as well as the need to carry out a complex of differentiated anti-epidemic (preventive) measures within the framework of the state sanitary-epidemiological surveillance in order to localize and eliminate the imported focus and avoid the spread of the infection.