The paper considers the key areas of international activities of the Federal Service for Surveillance on Consumers’ Rights Protection and Human Well-being in strengthening cooperation with specialized agencies of foreign countries in the global provision of sanitary-epidemiological welfare of the population at the current stage. Consistent work to strengthen the international network to counter emergency situations of a sanitary and epidemiological nature through effective interaction in the field of rapid response with partner countries in the near and far abroad, including through the organization of joint scientific and practical centers for the study and prevention of infectious diseases is presented. It is shown that the programs being implemented are aimed at strengthening the national healthcare structures of partner countries to achieve independence in the implementation of monitoring and anti-epidemic measures and building a single epidemiological space, independent of the influence of global and regional geopolitical fluctuations. The relevance of increasing interstate cooperation in the field of analysis and control of biological threats, primarily infectious diseases with the potential for emergencies of a sanitary and epidemiological nature of international concern, in the South American region is considered. The currently expanding strategic biosecurity collaboration with the Bolivarian Republic of Venezuela through the establishment of the first joint research center in the South American region is described. The first results of the joint work of Russian and Venezuelan specialists are presented, confirming the successful integration of Russian experience in monitoring and preventing biological threats into the system of ensuring the sanitary and epidemiological well-being of the Venezuelan population. Promising areas for further joint research are discussed.

Mobile laboratories for implementing anti-epidemic measures in the territories of natural plague foci perform an important function of ensuring sanitary-epidemiological well-being of the country. The aim of the study was to determine the range of areas and tactics for deploying mobile laboratories to ensure the current tasks of immunological monitoring over the health status of the population at risk in the territory of a natural plague focus. Retrospective analysis of the results of long-term immunological monitoring of the risk contingent vaccinated against plague was carried out. The possibilities and prospects for using a mobile laboratory for immunological monitoring within the framework of ensuring the tasks and functions of the Rospotrebnadzor have been determined. Mobile laboratories for immunological monitoring expand the capacities to solve operational issues related to the provision of specific prophylaxis of particularly dangerous infectious diseases, and their deployment as part of other mobile units of the Sanitary-Epidemiological Service will contribute to a more accurate delimitation of the territory, volume, scope and priority of any given preventive measure.

The aim of the study was to develop an algorithm for intraspecific differentiation of tularemia agent strains using a set of approaches based on amplification and sequencing technologies.Materials and methods. 97 strains of Francisella tularensis of various subspecies, biovars and subpopulations from the State Collection of Pathogenic Bacteria of the Russian Research Anti-Plague Institute “Microbe” were used in the work. The intraspecific identification of tularemia agent strains was carried out using the “F. tularensis-4c” system; analysis of the variability of the RD1 differentiation region, the sdhA gene, by applying the disk diffusion method using disks with erythromycin. Fragment Sanger sequencing was performed on a 3500 XL genetic analyzer (Applied Biosystems, USA) taking into account the manufacturer’s recommendations. Sequence homology assessment was conducted using the BLAST algorithm, the GenBank NCBI database, MEGA11 v11.0.13 and Unipro UGENE v50.0 software.Results and discussion. Subspecies- and biovarspecific mutations have been detected in the 23S rRNA gene. Promising regions of this gene for further investigation have been identified using fragment sequencing. A comprehensive scheme for intraspecific differentiation of tularemia microbe strains has been put forward, where at the first stage the subspecies and biovar japonica are determined, and at the second stage, the results are verified based on the determination of mutations in the 23S rRNA gene. The effectiveness of the proposed integrated approach has been confirmed in a study of 97 collection strains of tularemia agent. The conducted research allows for rapid identification of tularemia agent strains of different subspecies and verification of their taxonomic appurtenance using molecular-genetic methods, expanding data on the circulation of various subspecies, biovars and subpopulations of the pathogen in Europe, Asia and other regions of the world.

The current stage of transformation of the global healthcare architecture dictates the need to unite international efforts to create conditions for cooperation and building up the capacity to respond to various biological threats between all participants in the international arena. The paper demonstrates the advantages of Russian approaches to organizing the sanitary and epidemiological service to counteract biological threats. The most striking examples of the country’s participation in the emerging architecture of global healthcare are shown, which include the participation of the Russian Federation in the implementation of interstate programs aimed at eliminating dangerous infectious diseases. The strategy for countering modern biological threats implemented by the Russian Federation in the international arena is outlined, focused primarily on strengthening the methodological, technological, and human resources potential, enhan cing national capabilities for epidemiological surveillance and response to emergencies in the field of sanitary-epidemiological well-being of the population of partner countries. The main areas of cooperation with partner countries are considered. The key results of joint international projects both in the near and far abroad are presented, reflecting significant successes in strengthening the national potential of the partner countries of the Russian Federation in the field of rapid response to emerging threats in the field of biological safety and ensuring sanitary and epidemiological well-being. The achieved results of interstate cooperation in the field of ensuring global biological security and the active participation of the Russian Federation in the development and implementation of global instruments in the field of monitoring and responding to public health emergencies constitute the significant contribution of the Russian Federation to the current formation of the global healthcare architecture.

Ensuring the sanitary and epidemiological well-being of the population is impossible without the development of international cooperation in the field of preventing and responding to biological emergency situations. To date, a unified system of monitoring and prompt response to emergencies in the field of public health of sanitary-epidemiological nature has almost been formed in the space of the Commonwealth of Independent States (CIS). To implement legitimate interaction between the Commonwealth countries, it is necessary to develop a regulatory and methodological framework. For this purpose, the Coordination Council on the issues of sanitary protection of the territories of the member states of the Commonwealth of Independent States from the importation and spread of particularly dangerous infectious diseases has drawn a number of interstate documents, which were subsequently put into effect in the CIS. The paper presents the activities of the Coordination Council aimed at establishing and maintaining the functioning of a unified system for monitoring and prompt response to emergency situations and developing a regulatory and methodological framework that allows legitimate interaction between the Commonwealth countries.

The study presents the data on organization of laboratory testing of clinical and environmental samples within the framework of establishing the etiology of the acute intestinal infections outbreak, performed by the specialists of the joint SAET of the Rospotrebnadzor in Dolisie (Republic of the Congo) in the period of 07–24 July, 2023.Materials and methods. In order to identify the causative agents of cholera and other acute intestinal infections of bacterial and viral nature, 177 clinical and environmental samples were tested, as well as cultures on solid nutrient media and bacterial suspensions. A total of 1023 tests were carried out by polymerase chain reaction (PCR) and 305 – using bacteriological method.Results and discussion. The causative agent of cholera has not been detected in any of the samples tested. Using the PCR method, markers of acute intestinal diseases agents (Salmonella spp., Shigella spp., Campylobacter spp., Rotavirus A) have been identified in 23 clinical samples and 1 sample of bacterial suspension. No DNA/RNA of pathogens has been detected in environmental samples. During culture studies, Salmonella enterica serovar Typhi have been isolated from 8 clinical samples, and their antibiotic sensitivity has been determined. Applying whole-genome nanopore sequencing, using the MinIon platform (Oxford Nanopore Technologies, UK), nucleotide sequences of 4 S. Typhi isolates have been investigated and deposited in the international database NCBI GenBank (No. CP141260, CP141193, CP141194, CP141195). Additionally, the analysis of initially sterile samples (blood, peritoneal fluid, intraoperational samples) from the patients of General and Reference hospitals of Dolisie has resulted in the identification of 5 cultures of non-fermenting bacteria, and their antibiotic sensitivity has been determined.

The review presents the main results of scientific and technical cooperation between the Russian Federation and the Republic of Guinea over 10 years of joint work, since the deployment of a group of Russian specialists and mobile laboratories from the mobile complex of the specialized anti-epidemic team of the Rospotrebnadzor in August 2014 to provide practical and methodological assistance in eliminating the epidemic caused by the Ebola virus. The main areas of cooperation are the strengthening of laboratory and hospital facilities, joint research and training of specialists from specialized institutions in Guinea on biosafety issues. During the implementation of the Russian Federation programs of assistance to the Republic of Guinea in combating infectious diseases, public-private partnership mechanisms with UC “RUSAL” were involved, which made it possible to bring Russia’s participation in eradicating the epidemic of Ebola virus disease and subsequently strengthening Guinea’s national capacity to combat biological threats to the maximum effect.

The aim of the study was to identify structural differences in the Brucella omp25 and omp2a genes, which make it possible to determine their taxonomic position.Materials and methods. The objects of the study were the nucleotide sequences of the complete genomes of 48 Brucella strains presented in the GenBank NCBI database. To assess sequence homology, the BLAST algorithm and the MEGA 11 program were used.Results and discussion. In 13 species of Brucella and Brucella spp. with unknown species appurtenance, HindIII, EcoRV and EcoRI, AluI restriction profiles of genome regions have been reproduced in silico, including, omp25 and omp2a genes, flanked by primers 25A-25B and 2AB-2AA, respectively. In the omp25 gene, 11 non-synonymous and 24 synonymous mutations have been detected; two deletions: ∆103–108 bp – in В. nosferati, ∆562–597 bp – in В. Ovis; and ACT insertion after 585 bp – in В. vulpis. The variability of the omp2a gene in the studied Brucella strains was significantly higher. 138 SNPs have been identified, of which 60 lead to amino acid substitutions, 2 – form stop codons, and an additional deletion ∆424–561 bp – in В. abortus 1, 2, 4 biovars. Single mutations in the omp2a and omp25 genes had both group specificity – for several species, and unique – for a specific species or biovar of the pathogen. Allelic profiles of the omp25 and omp2a genes have greater resolution than their restriction profiles studied. The identified changes in the structure of the omp25 and omp2a genes correlate with the circulation of individual Brucella species and biovars in the organism of certain carriers. These genes show the presence of deletions, insertions and single polymorphic nucleotides specific to species, groups of species and, in some cases, biovars of the pathogen.

Sanitary and quarantine control (SQC) at the state border of the Russian Federation is the first barrier to the importation and subsequent spread of diseases on the territory of the country. Every year the number of registered outbreaks of infectious diseases in the countries of the world increases, which entails an increase in published information, some of which is unreliable and requires verification. At the same time, against the background of the development of international tourism, increase in passenger traffic, the risk of infectious diseases importation into the territory of Russia rises manifold, which creates the need for modernization of information and technical support of the SQC. In connection with the above, the aim of the work was to develop a scientifically substantiated system of informatization and digitalization of SQC, which resulted in the introduction of an automated risk assessment system as regards importation of dangerous infectious diseases (AIS “Perimeter”) at all sanitary-quarantine checkpoints (SQP). Materials and methods. The information system was created using the following software platforms: Laravel, VueJs. The official websites of the Ministries of Health of the respective countries, data from the official regional websites of WHO, regional centers for disease control and prevention (CDC), and data from the ProMED-mail system were used as sources of information on infectious morbidity in the countries of the world. Results and discussion. Implementation of AIS “Perimeter” has brought about the maximum possible efficiency in the targeted informing of SQP officials about the current epidemiological situation in the countries of the world; an effective tool for monitoring the situation at the federal level in real-time mode. It facilitates the work of SQP, staff related to conducting standard operational procedures, due to considerable decrease in the volume of routine activities to keep records. The proposed in the AIS expert risk assessment as regards importation of infectious diseases allows SQP employees, based on reliable information, to make timely decisions on the need to conduct SQC and exclude erroneous actions in the essential set of measures within the framework of SQC implementation, while minimizing subjectivity with respect to decision making.

The aim of the study was to develop methodological approaches to assessing the economic damage associated with the incidence of hemorrhagic fever with renal syndrome (HFRS) and to calculate the economic damage by the example of an outbreak of HFRS in the Saratov region in 2019. Materials and methods . The paper analyzes the economic indicators of the Federal State Statistics Service; data on the incidence of HFRS in the Russian Federation for the period of 2019–2022. To calculate the cost of outpatient and inpatient medical care, as well as the costs associated with the medical follow-up of convalescents, the indicators of the Program of state guarantees of free provision of medical care to citizens for 2022 and for the scheduled period of 2023 and 2024 were used. The calculation of economic losses associated with the payment of temporary disability benefits was carried out according to the equation provided in the Federal Law No. 255-FZ dated December 29, 2006 (as amended on October 07, 2022). Economic losses associated with premature death at an economically active age were calculated based on the value of unproduced GDP due to lost years of life in the corresponding age group. Results and discussion. The costs of treatment, rehabilitation and payment of temporary disability benefits for 1 case of HFRS at the age of 0 to 56.5 years for the female population and from 0 to 61.5 years for the male population amount to 140 495 rubles; over the age of 56.5 years for the female population and 61.5 years for the male population – 95 412 rubles, respectively. Each fatal case of HFRS aged 0 to 16 years among the male population costs the state 38 976 231 rubles; among the female population – 34 708 331 rubles; in active working age – the value of economic damage varies depending on the age of the person who died of HFRS. The economic damage of the outbreak of HFRS in the Saratov Region (2019), taking into account the direct expenditures of the healthcare system and indirect losses of the country’s economy amounted to 441 453 432 rubles. It is of note that the structure of the main damage is dominated by indirect losses in the economy caused by the premature death of people in economically active age.

In recent decades, an increase in the number of cases of detection of the Usutu virus (Usutu, USUV, Orthoflavivirus usutuense) (family Flaviviridae, genus Orthoflavivirus) has caused great concern among medical professionals, including virologists and specialists in infectious diseases, especially since its appearance in Europe, where the pathogen caused mass birds die-off, and annually registered human cases. This review provides information about the structure of the virus and its genetic variants, geographical distribution and features of circulation in Europe and Africa, the methods and principles used to indicate and identify this pathogen, as well as the main symptoms of the disease it causes. An assessment of the environmental prerequisites for the occurrence of outbreaks of the disease caused by the Usutu virus on the territory of the Russian Federation was also carried out.

The aim of the study was to develop a method for intraspecific differentiation of the tularemia microbe: subspecies tularensis (subpopulations AI and AII), holarctica (biovars japonica, EryS/R), mediasiatica, and novicida using multilocus real-time PCR. Materials and methods. We used 48 strains of F. tularensis of various subspecies, biovars, and subpopulations. Intraspecific appurtenance of the strains was carried out on the basis of the analysis of the RD-1 region variability applying PCR, the sdhA gene by Sanger fragment sequencing and by the disk diffusion method using disks with erythromycin. The selection of primers and probes was performed using the software available at www.genscript.com and GeneRunner 6.5.52. Sequence homology was assessed using the BLAST algorithm and the GenBank NCBI database. Results and discussion. New data on the structure and occurrence of the differentiation regions RD-8, RD-12, RD-28 of FTT1122c gene and its homologous sequences in strains of tularemia microbe of various subspecies have been obtained. Novel RDhm 346 bp in size, characteristic of strains of the subsp. mediasiatica , holarctica , which is deleted in subsp. tularensis and absent in subsp. novicida has been detected. Based on the detection of the FTT1670 , FTT1122 с , FTT1067 , FTW_2084 loci, a multilocus real-time PCR has been developed – “ F. tularensis 4c”, providing for identification of all subspecies of the tularemia microbe, separately for the biovar japonica of the Holarctic subspecies and subpopulations AI, AII of the subspecies tularensis . The PCR specificity was confirmed in the study of strains of tularemia microbe from the fund of the “State Collection of Pathogenic Bacteria” at the premises of the Russian Reserarch Anti-Plague Institute “Microbe”. The results obtained expand the concept of intraspecific genetic heterogeneity of tularemia microbe and possibilities of identifying the causative agent of tularemia using molecular-genetic methods. They are important for understanding the processes of adaptation of the pathogen to circulation in the host organism and environmental objects, the course of evolution and formation of new species of Francisella .

The risk of importation of infectious diseases is an urgent threat to sanitary and epidemiological well-being of the population, both at the level of individual countries and interstate associations, and globally. The territory of any country has a backdrop of hazards; therefore, the aim of the work was a comprehensive assessment of risk of infectious disease importation onto the territory of Russia for early and effective response to emerging biological threats. Materials and methods. We used information on the structure of passenger traffic and the number of persons arriving in Russia according to the portal of the Unified Interagency Information and Statistics System. The data on the incidence of infectious diseases which require measures on sanitary protection of the territory of Russia is provided according to the official regional websites of WHO, regional Centers for Disease Control and Prevention (CDC), Ministries of Health of the respective countries. The risk of importation of infectious diseases was estimated in points in compliance with an original methodology developed with the participation of the authors. Results and discussion. We have determined the structure of the passenger traffic across the borders of Russia and the most relevant infectious diseases that pose a risk of importation, as well as the countries, from where the importation of infections is most likely to occur. It is outlined that importation of dengue fever and cholera from the Southeast Asian region, dengue from the Western Pacific region, cholera and malaria from the Eastern Mediterranean region, cholera, malaria and dengue from the American and African regions is most probable.

The most important component of strengthening the potential for responding to biological threats both at the national and interstate levels is the formation of a unified system for monitoring and responding to emergencies (ES) of sanitary-epidemiological nature in the CIS territory.The aim of the work was to review the systems for monitoring and responding to emergencies of sanitary-epidemiological character in the CIS countries by the example of the Russian Federation, the Republic of Belarus, the Republic of Kazakhstan and the Kyrgyz Republic, to characterize the main areas of international cooperation on countering biological threats and coordinating international response measures in the CIS countries.Materials and methods. Information and analytical materials provided by organizations responsible for epidemiological surveillance and control in the CIS countries, Internet sources, and publications were used for the study.Results and discussion. The organization and functioning of the systems for monitoring and responding to emergencies in the CIS countries is a state function. It includes, as a rule, the national, regional (sub-national) and territorial (local) levels, which have horizontal and vertical connections. The legal framework is made up of documents of the legislative level. Interdepartmental interaction in response to emergencies is carried out both at the republican level and in administrative territories; the basis for interaction is the integrated planning of preventive and anti-epidemic measures and the functioning of the relevant organizational structures on an ongoing basis. Since 2015, with the support of the Government of the Russian Federation, programs have been implemented aimed at assisting partner countries in the implementation of the International Health Regulations (2005) in order to increase national response capacity and form a unified sanitaryepidemiological emergency response system in the CIS countries. The main areas of collaboration are strengthening the material and technical base and human resources of specialized institutions and scientific cooperation. As a result of the program implementation, a unified system for monitoring and prompt response to emergencies in the field of public health of sanitary-epidemiological nature has essentially been formed in the CIS countries to date, uniting more than 15 specialized institutions from 8 CIS countries.

The aim of the study was to develop a methodological approach to determination of Brucella suis biovars through multilocus PCR with real-time registration of results.Materials and methods. We used 16 strains of B. suis of various biovars, B. neotomae and B. canis – 2 strains of each. Determination of the taxonomic affiliation of Brucella strains was carried out according to the Bruce-ladder, Suis-ladder, BRU-DIF protocols. The selection of primers and probes was performed using the software on the website www.genscript.com and the GeneRanner 6.5.52 program. Fragment sequencing according to Sanger was performed on a 3500 XL genetic analyzer in accordance with the manufacturer’s recommendations. Nucleotide sequence homology was assessed using the BLAST algorithm and the GenBank NCBI database.Results and discussion. An analysis of the structural organization of IncP and GI-3 genomic islands has been carried out in B. suis strains of various biovars. It has been established that in strains of B. suis II, IV biovars and B. canis, the terminal part of the BRA0368 gene, comprising 21 nucleotides (repeated in the BRA0367 gene) and the “TAA” stop codon, as well as almost the entire sequence of the BRA0367 gene were lost, owing to homologous recombination in the IncP genome island. A 21-nucleotide direct repeat and the “TGA” stop codon of the BRA0367 gene replaced the analogous region of the BRA0368 gene which resulted in the deletion the size of 185 bp. No differences have been noted in the structure of GI-3 in biovars. The evidence obtained made it possible to develop the approach (SuisDIF) for differentiating B. suis biovars, based on the amplification of genes located in the IncP and GI-3 genomic islands using real-time PCR. Its specificity was confirmed in the study of B. suis strains from the fund of the State Collection of Pathogenic Bacteria of the Russian Research Anti-Plague Institute “Microbe”. The conducted studies expand and supplement the data on the genetic heterogeneity of Brucella species and biovars. The proposed method for differentiating biovars of B. suis using multilocus PCR with real-time registration of results enhances the capacities for Brucella identification using molecular-genetic methods.

The aim was to present the experience of using mobile laboratory for monitoring and diagnostics (MLMD) during the epizootiological monitoring of the northern provinces of Vietnam. MLMD was transferred by Federal Service for Surveillance in the Sphere of Consumers Rights Protection and Human Welfare to the Socialist Republic of Vietnam as part of implementation of cooperation programs on combating infectious diseases. The use of MLMD made it possible to obtain new information on the circulation of pathogens of natural-focal infectious diseases on the territory of Vietnam. It also provided the necessary conditions for conducting research using methods of express diagnostics, bacteriological analysis, performing a full cycle of work – from the receipt of samples to the disinfection and destruction of infected material in compliance with the requirements of biological safety in the field. The effectiveness of using mobile laboratories in response to the emergencies of sanitary and epidemiological nature, both to strengthen stationary laboratory bases and to organize diagnostic studies in remote regions, has been shown. The use of MLMD for the diagnosis of COVID‑19 has been an effective component of countering the new coronavirus infection in Vietnam and significantly increased the volume of testing in the country.

INTRODUCTION Acute febrile diseases kill more than 250,000 people annually in West Africa. Malaria and typhoid fever traditionally occupy most of the total structure of registered fevers. However, these data do not fully reflect the true overall disease patterns in the West African region. This is due to the fact that diagnosis is mainly based on the clinical signs of the infectious process, suggesting that a certain number of diseases may be caused by arboviruses. The detection of specific antibodies (ABs) to infectious pathogens in the blood sera of residents of a particular area is a reliable indicator of the circulation of these pathogens in a particular territory.The aim of this study was to determine the prevalence of antibodies to a number of arboviruses: Dengue (DENV), West Nile (WNV) (family Flaviviridae), Crimean-Congo hemorrhagic fever (orthonairo)virus (CCHFV), Batai (Batai virus), Bhanja (BHAV) (order Bunyavirales), Chikungunya (CHIKV), and Sindbis (SINV) (family Togaviridae) in the population of the Republic of Guinea. MATERIAL AND METHODS In total, a panel of 2,620 blood serum samples from people living in all landscape and geographical areas of Guinea was collected for the study. Detection of IgG antibodies was performed using an enzyme-linked immunoassay (ELISA). RESULTS In total, ABs to Batai virus were detected in 144 samples (5.5%), BHAV in 58 (2.2%), WNV in 892 (34.0 %), DENV in 659 (25.2 %), CCHFV in 58 (2.2 %), CHIKV in 339 (12.9 %), and SINV in 52 samples (2.0 %). DISCUSSION The obtained results indicate serological evidence of the spectrum of arboviruses in the population of all landscape and geographical zones of the Republic of Guinea, confirming their active circulation in this territory. CONCLUSION Given the high epidemiological significance of arbovirus infectious diseases, it is an urgent task to continue studying its share in the structure of febrile diseases in the territory of the Republic of Guinea.

Genetic diversity of SARS-CoV-2 isolates circulating in the Republic of Guinea in May and June 2020, as well as in March 2021, has been demonstrated using fragment (S gene) and whole genome sequencing of 14 strains. Analysis of nucleotide sequences and phylogenetic constructs make it possible to divide the studied strains into 3 groups. Comparison of the obtained data with the already available epidemiological data proves the initial importation of COVID-19 from Western European countries, and also demonstrates four independent import routes in two time periods (March 2020 and no later than March 2021).

The review presents the materials on the use of mobile laboratories, developed in the Russian Federation, in the framework of four main areas: monitoring of territories to identify the circulation of pathogens of natural-focal infectious diseases; monitoring of territories during the exacerbation of the epizootic situation; participation in the elimination of outbreaks of infectious diseases; monitoring of territories to control and predict the epidemiological and epizootiologic situation in preparation for mass events. The tactical and technical characteristics and the procedure for organizing the operation of the mobile laboratory for monitoring and diagnostics mounted on the platform of the KamAZ chassis are considered. A distinctive feature of the laboratory from the existing Russian and foreign counterparts is the availability of the necessary conditions for conducting research using bacteriological analysis, rapid and accelerated diagnostic methods, and performing a full cycle of works – from the preparatory stage to the destruction of infected material. Hightech equipment allows the realization of two research schemes: the first – bacteriological analysis alongside the PCR, which ensures high reliability of the results; the second – conducting the PCR at the first stage, and when identifying genetic markers of the pathogen – performing bacteriological analysis of positive samples in order to isolate the culture of the pathogen and identify it subsequently. The second scheme will reduce the volume of bacteriological studies; make changes in the tactics of epizootiological survey. Tests of the mobile laboratory have demonstrated the effectiveness of its use in the epizootiological examination of natural plague foci, including cross-border ones. Owing to the use of a mobile laboratory in the Gorno-Altaisk high-mountain natural focus of plague, a new epizootic site was identified, located in a remote area, used by the population as a summer pasture for grazing domestic animals. The use of mobile laboratories will strengthen the laboratory base of institutions that monitor particularly dangerous, natural-focal and other dangerous infectious diseases; will help to bring the advanced diagnostic technologies directly to the natural focus, reduce the risk of epidemic complications due to plague and other particularly dangerous infections in cross-border natural foci.

In 2013-2016, a large-scale Ebola virus diseas (EVD) outbreak hit the countries of West Africa for the first time. Thus provoking a health crisis. The most affected countries were Sierra Leone, Liberia and the Republic of Guinea. Since the end of the outbreak in 2016, there have been no new cases until recently. In February 2021, the Republic of Guinea announced about laboratory-confirmed EVD cases in its territory. By April 12, 2021, an Ebola virus disease outbreak in the province of N’Zerekore (Gueke sub-prefecture) of the Republic of Guinea had affected 16 people, 9 of whom had died. The origin of this outbreak is still unknown. This paper considers various hypotheses of its emergence. Within the frames of the study sequencing and analysis of the whole genome sequence of the strain that initiated the epidemic process have been carried out. The most likely cause of this outbreak, according to the results obtained, should be deemed a long-term persistence of the virus in the body of survivors, followed by a relapse of the disease and transmission among contact persons.