Распространение новой коронавирусной инфекции в субъектах Российской Федерации обусловлено последовательным вовлечением в эпидемический процесс различных групп восприимчивого местного населения с отличающимся иммунным статусом и, как следствие, сопровождается генетической изменчивостью вируса SARS-Cov-2, что в свою очередь может привести к формированию новых штаммов возбудителя. Стабилизация уровня заболеваемости населения и наметившаяся тенденция к ее снижению на фоне масштабных противоэпидемических (профилактических) мероприятий, в т.ч. прививочной кампании свидетельствует о необходимости изучения генетической вариабельности S-белка вируса SARS-Cov-2 являющегося основным компонентом вакцин в отдельно взятом субъекте Российской Федерации. В связи с этим, цель работы состояла в сравнительном анализе геномного разнообразия и полиморфизмов S-белка возбудителя COVID-19 циркулирующего на территории Орловской области. Исследовано 100 образцов биологического материала от больных COVID-19 зарегистрированных в Орловской области. Секвенирование проводили на приборе MiSeq (Illumina, США), сборка геномов осуществлялась путем выравнивания на референсную последовательность уханьского варианта вируса SARS-Cov-2. Установлено, что на территории Орловской области циркулируют штаммы возбудителя COVID-19 принадлежащие к ветви «B.1.1». Доминирующим вариантом для Орловской области является вариант B.1.1.130. В 54,1 % случаев в изученных образцах выявлен полиморфизм E484K Spike-белка, с которым ряд исследователей связывают уклонение от иммунного ответа макрорганизма.

The aim of the review was to analyze and assess the epidemiological situation on cholera in the world and Russia in 2013–2022 and to make a forecast for 2023. Over the period of 2013–2022, 500 administrative territories affected by cholera were identified in various regions of 71 countries of Asia, Africa and America (the Caribbean region) with formation of 69 endemic foci in 16, 41 and 12 countries, respectively. In 2022, 1 209 301 cases of cholera were registered in 36 countries of the world. The intensity of epidemic process in Asian countries (Syria, Lebanon) increased. Unfavorable epidemiological situation on the African continent persisted. Epidemics and large outbreaks, which began in 2021–2022 due to emergency situations (ES) of social and natural character, continued. The prediction of the stability of the epidemiological situation on cholera in the territories of constituent entities of the Russian Federation (RF), given for 2022, has been confirmed. In 2022, 43 non-toxigenic strains of Vibrio cholerae О1 were isolated from surface water bodies, 8 V. cholerae nonO1/nonO139 strains – from humans. Similarity of those strains with genetically closely related ones isolated in the course of monitoring in previous years in Russia, Donetsk People’s Republic (DPR) and Zaporozhye Region was demonstrated. In 2023, the risks of importation of the infection into RF are retained. It is associated with the intensification of epidemic processes in Asian, African and Caribbean region countries. The extended border with Ukraine, to where importation of cholera from endemic countries is possible, contributes to increased degree of threat. Bioterrorism is also not excluded. The consequences of a possible cholera epidemic complication in DPR, Lugansk People’s Republic, Zaporozhye and Kherson Regions are exacerbated by social emergencies resulting in disruption of infrastructure, interruptions in water supply, etc. In the absence of implementation of the risks of importation of this infection on the territory of RF, a stable epidemiological situation on cholera will be retained. Detection of non-toxigenic V. cholerae O1 strains (including probability of clonal complexes formation), as well as strains of non-O1/non-O139 serogroups, which can be etiological factors of sporadic cases or outbreaks of diarrheal diseases, in surface water bodies is predicted.

Objective: To compare the genomic diversity of SARS-CoV-2 strains that were spread in the Rostov region and the Republic of Crimea in the period from March to June 2021.Materials and Methods: A total of 194 samples were sequenced and 186 genovariants were recognized among them using the Pangolin program. Multiple alignment was performed and dendrograms were constructed for the samples belonging to the alpha and delta genovariants.Results: Changes of the predominant genovariants were revealed for territories of the Rostov Region and the Republic of Crimea from March to June. An increasing percent of the alpha variant was observed in both regions during the spring followed by the rapid emergence of the delta variant, which became predominant in June.Conclusion: It was shown that alpha variant samples from the Rostov region share a pool of common mutations, while in contrast, alpha variant samples from the Republic of Crimea are closer to those sampled from Moscow and Moscow region. At the end of May, the delta gene variant begins to be revealed, which is rapidly replacing other lines in all the territories considered in this study.

The aim of the work was to summarize the results of cholera monitoring in 2021, to assess current trends in the development of the epidemic process, and to predict the epidemiological situation in the Russian Federation for 2022. It was established that within the period of 2012–2021, 4117264 cases of cholera with the spread of infection across 83 countries on all continents were registered in the world and there was a downward trend in the incidence in Asia and Africa. The dynamics of monthly morbidity in 2021 was associated with emergencies as factors of epidemiological risk. Epidemics and outbreaks of cholera were documented against the background of COVID-19 pandemic and laid a double burden on healthcare systems. At the same time, based on the overview of the results of cholera monitoring in the constituent entities of the Russian Federation, it was shown that the forecast of epidemic well-being given for 2021 was fully justified. It has been determined that the increase in the number of non-toxigenic strains of Vibrio cholerae O1 (67) isolated from water bodies compared to 2020 (25) is mainly due to the appurtenance of a number of isolates to clonal complexes. The study of phylogenetic relation has demonstrated that the detection of strains with genotypes which were previously identified in the isolates evidences the persistence potential. The identification of strains with new genotypes, which were earlier established in the strains circulating in other territories, pointed at the possibility of the occasional importations. The forecast of the epidemiological situation on cholera in Russia for 2022 is associated with the continuous existence of risks of introduction. If these epidemiological risks are not realized, a favorable epidemiological situation is predicted regarding this infection in the country. It is expected that the detection of epidemiologically insignificant strains of V. cholerae O1 in environmental water bodies, along with their clones and/or clonal complexes, will remain, including strains that may be an etiological factor in sporadic cases or outbreaks of disease.

The complication of cholera epidemic situation in Ukraine (2011) caused the reinforcement measures on monitoring Vibrio cholerae in seawater in Taganrog Bay in the framework of measures for prevention of the spread of infection over the territory of the Rostov region and the country. Phenotypic and genotypic features of 3 selected atoxigenic strains of Vibrio cholerae eltor O1 and 1 toxigenic strain of V. cholerae eltor Inaba № 301, containing the hybrid prophage were characterized. With great probability there was established the absence of association of this strain with the outbreak of infection within the territory of the neighboring country, but there was revealed his relationship with to imported strains (1999, 2005). Atoxigenic strains were similar to strains previously detected in water bodies of the Rostov region. The implementation of the set of measures for the strengthening of epidemiological control permitted to prevent the importation of infection into the territory of the Russian Federation in 2011 - 2012.