Preview

Problems of Particularly Dangerous Infections

Advanced search
No 3 (2023)
View or download the full issue PDF (Russian)
6-14 2768
Abstract

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.

REVIEWS

15-21 588
Abstract

The review focuses on the means of personal protection of people from blood-sucking arthropods, mainly from Ixodidae ticks. Individual (personal) protection of humans is an important component of nonspecific prevention of natural-focal vector-borne diseases. The paper considers statistical data describing the level of significance and relevance of the information about the infections transmitted by ticks, for instance, tick-borne viral encephalitis, tick-borne borreliosis etc. Presented are the characteristics of different groups of personal protection means: insectoacaricidal, repellent, and insectoacaricidal-repellent ones. Indicators of their effectiveness are assessed; their practical use, as well as the features of special protective clothing and the necessity of its application is described. The toxicity of protective clothing is reduced through a lining fabric, local inserts of fabric with insectoacaricidal impregnation and the use of underwear. Different interpretation of the term “repellent” in the domestic and foreign literature, and also two different approaches (“Eastern” and “Western”) to the design and manufacture of personal protection means for people against attacks of blood-sucking arthropods, including Ixodidae ticks, in Russia and Western Europe countries and the USA is discussed. The paper highlights the effect of different pyrethroid groups on the behavioral reactions of ticks. It is shown that in the Russian Federation the use of permethrin is prohibited for the treatment of protective clothing against blood-sucking arthropods, in particular against the taiga tick Ixodes persulcatus, which is the main vector of dangerous infections across the major part of the country (in the east of the European part, the Urals, Siberia and the Far East).

22-32 1735
Abstract

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.

33-42 609
Abstract

In the second half of the last century, a persistent focus of the disease caused by Sindbis virus was formed on the territory of Fennoscandia. In different countries, the disease is called Pogosta disease, Ockelbo disease and Karelian fever. The highest incidence rate is in Finland, where diseases are recorded annually, ranging from sporadic cases to large outbreaks with hundreds of patients. In other Scandinavian countries and in Russia, isolated cases of infection are currently being detected. The data on registered incidence and the results of seroepidemiological studies indicate an unequal dissemination of the infection in Fennoscandia, the causes of which need to be investigated. The review presents updated information on the pathogen, its distribution among the population and in the biocenosis of Fennoscandia, clinical features, diagnostics and epidemiological characteristics of the incidence.

43-50 894
Abstract

The aim of the work was to analyze the epizootic and epidemiological situation on leptospirosis in the territory of the Russian Federation in 2013–2022 and to forecast its development in 2023. The long-term dynamics of leptospirosis incidence in the Russian Federation tends to decrease. Cases were registered in 58 constituent entities of the Russian Federation, in all federal districts. The highest incidence rates were noted in the North-Western Federal District. When studying the material from small mammals using bacteriological, immunological and molecular-biological methods, Leptospira circulation was detected in 52 entities of the Russian Federation, in all federal districts. In 2023, sporadic cases of infection are to be expected in the territories of the North-Western Federal District, the Central Federal District, and the Southern Federal District; imported cases of infection from countries with subequatorial and equatorial climates are not excluded.

ORIGINAL ARTICLES

51-58 598
Abstract

The aim of the work was to estimate the prevalence of HIV, HBV and HCV markers among pregnant women and their male partners in the Republic of Guinea.

Materials and methods. The material of the study was blood plasma samples from 140 pregnant women living in Kindia prefecture and N’Zerekore prefecture, as well as 60 male partners who reported sexual contact with HIV-infected persons. The samples were examined for the presence of serological (HBsAg, HBeAg, antibodies anti-HBs IgG, anti-HBcore IgG, anti-HBe IgG, anti-HCV IgG, Ag/Ab-HIV) and molecular (HBV DNA, HCV RNA, HIV RNA) markers.

Results and discussion. The age of the examined pregnant women ranged from 13 to 55 years and was on average (26.29±9.67) years. The age of men varied from 15 to 60 years, on average – (29.05±11.99) years. When assessing the prevalence of serological markers, antibodies to HCV were detected in 2.14 % cases in women and in 3.33 % cases in men. Antibodies to HIV were found in 6.43 % and 6.67 % women and men, respectively. Serological markers associated with HBV were detected in 80.71 % (HBsAg – 13.57 %) of women and 81.67 % (15 %) of men. In the pregnant women, HCV RNA was not detected, HIV RNA was revealed in 1 case, HBV DNA was identified in 26 cases (18.57 %), including 5 % HBsAg-negative hepatitis B cases. In the men group, HCV RNA and HIV RNA were detected in 3.33 % and 6.67 % cases, respectively. HBV DNA was determined in 16.67 % of men, including latent hepatitis B in one person. A significantly higher incidence of HIV in men compared to women is shown (χ2=3.907 at p<0.05). The relative risk of HIV infection in men is nine times higher than in women: RR=9.333; p=0.0291; 95 % CI: 1.065–81.815 %. Four out of five identified HIV infection cases were co-infected with HBV and/or HCV. There is an obvious need to introduce screening for HIV, HCV, HBV, including latent hepatitis B, into routine laboratory diagnostics during examination of pregnant women and their partners, followed by couples counseling and vaccination against hepatitis B virus.

59-65 484
Abstract

Six cultures of tularemia microbe from fallen and captured live animals were isolated during epizootiological monitoring in the steppe focus in the south-east of the Rostov Region in 2020 against the background of extensive epizootics in the populations of the common vole Microtus arvalis obscurus and the public vole Microtus socialis.

The aim of the work was to develop an SNP-typing scheme and to conduct a comparative study of the phylogenetic relations between Francisella tularensis strains isolated in the Rostov Region (2020) and strains from other regions.

Materials and methods. Genome-wide sequencing was performed on the MiSeq Illumina platform. The author’s software GeneExpert, PrimerM and VirtualPCR, written in the Java programming language, were used for the analysis.

Results and discussion. The strains of tularemia agent, isolated on the territory of the Rostov Region in 2020, can be allocated to two different clusters. It is established that two strains of tularemia pathogen (F0884 and F0889) isolated in Turkey are genetically close to some isolates circulating in the Rostov Region. A unique INDEL marker characteristic of this group of strains has been identified. The comparison of our proposed typing scheme with the scheme of “canonical” SNPs has showed a fairly good consistency and convergence of results within large clusters, meanwhile using a set of 6626 SNPs allows for differentiating the strains within one canSNP type. It is revealed that the vaccine strain has a common canSNP type with clinical and natural strains. A set of SNP markers has been selected for comparative analysis. A new INDEL marker that enables intraspecific typing of F. tularensis has been discovered and the possibility of its application in vitro and in silico has been comfirmed.

66-72 546
Abstract

There is a need to develop a new generation of anti-rabies vaccines that provide a protective level of antibodies after a single injection. Prospects for solving this problem are opened by the latest developments in the field of “reverse vaccinology”. The main parameter that determines the effectiveness of recombinant vaccines is the design of the antigen-coding sequence. In this regard, the aim of the work was to conduct a bioinformatic analysis of rabies virus (Rabies lyssavirus, Rhabdoviridae) peptides to identify immunogenic epitopes.

Materials and methods. Analysis of 5 candidate protein sequences of more than 100 strains and epizootic isolates of the rabies virus was performed using standard in silico prediction methods using Immune Epitope Database (IEDB) (NIH, USA).

Results and discussion. As a result of the analysis of primary amino acid sequences, carried out using the most commonly used bioinformatics tools, the number of immunogenic epitopes and the types of immune response detected (T- and B-cell epitopes, class I MHCbinding epitopes) were established for viral proteins: glycoprotein (G), nucleoprotein (N), phosphoprotein (P), matrix protein (M), RNA-dependent RNA polymerase (L). In the amino acid structure of these proteins, N- and O-glycosylation sites, signal peptides, and transmembrane domains were additionally identified. In order to predict the safety and efficacy of these proteins as components of recombinant vaccines, an in silico assessment of their physicochemical properties was carried out. Despite the fact that the predominant number of epitopes is concentrated in the structure of the glycoprotein, the epitopes of other proteins, ranging according to the level of antigenicity and conservatism, may also be of interest as components of preventive drugs or diagnostics. The presented data can be used in the design of the insert during the construction of a candidate virus-vector vaccine or control positive samples in diagnostic methods based on the indication of viral genome fragments.

73-79 380
Abstract

The aim of the work was to study the structure of the alkyl sulfatase (asu) gene in Vibrio cholerae strains of various serogroups, as well as to compare nucleotide and amino acid sequences of alkyl sulfatases using various methods of bioinformatic analysis.

Materials and methods. 483 strains of V. cholerae O1, O139 and nonO1/nonO139 serogroups were employed in the work. The search for the gene, its recurrence, and localization was carried out applying the Blast software. The nucleotide and corresponding amino acid sequences of the gene, as well as its structure, were studied using bioinformatic analysis. Sequencing was performed on the MiSeq (Illumina) platform. The enzymatic activity was detected using a medium, confirming the presence/absence of the gene by PCR in vitro and in silico.

Results and discussion. Bioinformatic analysis of the nucleotide and corresponding amino acid sequences of the asu gene has been carried out and its structure investigated. Four functional domains have been identified. In the beta-lactamase domain, a conservative amino acid sequence -HAHADH- has been found in all strains of cholera vibrios, which is part of the Zn2+ binding motif. It has been established that the alkyl sulfatase of cholera vibrios belongs to the family of Zn2+-dependent β-lactamases. Blast analysis has revealed the similarity of nucleotide and amino acid sequences of alkyl sulfatases in representatives of V. cholerae O1 and O139 serogroups (ctxAB+tcpA+) and representatives of the genera Aeromonas and Pseudomonas, which is in the line with the data of 3D modeling of the amino acid sequence structures of the alkyl sulfatase enzyme in these microorganisms. The bioinformatic analysis of nucleotide and amino acid sequences of alkyl sulfatases in cholera vibrios has showed the conservativeness of these sequences in toxigenic strains and the presence of a number of single mutations in the asu gene in atoxigenic ones. The presence or absence of the asu gene has been established by PCR in vitro and in silico and confirmed by the results obtained using the Blast program. It is demonstrated that the presence/absence of the asu gene correlates with the ability/inability of O139 strains to hydrolyze SDS on the medium. These results can be used in studying mechanisms of cholera vibrios adaptation, persistence and pathogenicity.

80-86 502
Abstract

From the very onset of SARS‑CoV‑2 spreading, active involvement in the COVID‑19 epidemic process made the healthcare professionals (HCPs) a vulnerable group with higher risks of contracting the disease, severe course and fatal outcome.

The aim. We aimed at studying the impact of specific and non-specific preventive measures on the risk of SARS‑CoV‑2 infection among the HCPs in a large industrial region settings during the COVID‑19 pandemic.

Materials and methods. We analyzed the data obtained using 1 905 questionnaires for the personnel of infectious hospitals for treatment of COVID‑19 patients and non-core healthcare facilities in a large industrial region during the COVID‑19 pandemic, 100 questionnaires on adherence of the employees to hand hygiene and antiseptics, the results of the tests for specific IgG to the SARS‑CoV‑2 nucleocapsid (2 200 samples), as well as the results of assessment of viral and bacterial contamination of the outer surface of the personal protective equipment for infectious hospital staff (108 specimens).

Results and discussion. In the course of the study, an effect of failure in the implementation of some specific and non-specific preventive measures on an increase in the incidence of COVID‑19 in various healthcare professionals has been identified. The COVID‑19 pandemic once again emphasized the need to save lives and health of the HCPs as socially significant category of citizens under the spread of pathogens with high epidemic potential, applying a complex of specific and non-specific measures that are not mutually exclusive.

87-92 393
Abstract

Temporary closure of schools is an effective anti-epidemic measure during periods of rising incidence of acute respiratory viral infections and influenza, which is confirmed by the results of a large number of scientific works. In particular, the effectiveness of this measure consists in reducing the incidence among students. In the context of the spread of COVID‑19 in the Russian Federation, like in many other countries, the temporary transfer of schoolchildren to distance learning has also been repeatedly introduced; however, it remains unclear whether the measure under consideration is effective in relation to the new coronavirus infection.

The aim of the study was to assess the epidemiological effectiveness of the temporary transfer of students to distance learning during the spread of COVID‑19 in the Saratov Region.

Materials and methods. The analysis was carried out on the basis of statistical data of the Rospotrebnadzor Administration in the Saratov Region on the incidence of COVID‑19 for the period of 2020–2022, as well as materials from published scientific papers.

Results and discussion. Analysis of the data on the school closure in 2020 has revealed a decrease in the incidence among schoolchildren (–42.9 %) and an increase in the incidence among people aged 65 years and older (+7.2 %); in 2021, there was a decrease in the incidence among schoolchildren (–15.6 %) and an increase in the indicator value as regards the elderly (+17.8 %); in 2022, another school closure led to an increase in the incidence of COVID‑19 among schoolchildren (+7.8 %) and people over 65 years old (+44.2 %). Based on the results obtained, one can conclude that the measure under consideration is inexpedient due to the fact that the most vulnerable category of the population (persons aged 65 years and older) is actively involved in the epidemic process, which in turn leads to a significant deterioration of the epidemic situation.

93-98 433
Abstract

The aim of the study was to assess the effectiveness of the developed anthrax magnoimmunosorbents (MIS) for the selective concentration of Bacillus anthracis spores and to increase the sensitivity of anthrax agent detection techniques, including when testing soil samples.

Materials and methods. We used 10 vaccine strains of B. anthracis and 30 strains of closely related bacilli of the genus Bacillus (B. cereus – 15, B. thuringiensis – 10, B. megaterium – 5) with typical species properties. The work was performed on three experimental batches of magnoimmunosorbents. DNA extraction and PCR setting was carried out in compliance with the instructions for reagent panel for B. anthracis DNA detection “ApliSens Bacillus anthracis-FRT”.

Results and discussion. It is shown that when using MIS, the sensitivity of the cultural method is increased by at least 7 times (taking into account the possibility of sorption of 1–10 or more spores on a sorbent particle). The sensitivity of the PCR method is improved by 10 times and amounts to 50 B. anthracis spores per 1 ml for the samples concentrated with the help of MIS. The sensitivity of the bacteriological method using MIS increases by a factor of 7.5 when testing the artificially contaminated with B. anthracis soil samples. Hence, application of the developed MIS makes it possible to significantly enhance the sensitivity of anthrax agent detection methods and can be considered as an effective means of sample preparation for the investigation of environmental objects (soil).

99-107 498
Abstract

The aim of the work was to identify genotypic features of clonal complexes formed by CTX–VPI+ strains of Vibrio cholerae isolated from water bodies of the Rostov Region in different years, based on bioinformatics analysis of their whole genome sequences (WGSs).

Materials and methods. Whole genome sequencing was performed on the MiSeq (Illumina) platform; identification of genetic determinants in WGSs and bioinformatics analysis – by means of BioEdit, BLASTN, BLASTP, CARD, Vector NTI software packages.

Results and discussion. The strains were almost identical in each group of 2002-, 2005-, 2007-, 2020-, 2021-, and 2022-isolates and were found at different points of water sampling over a longer or shorter periods of time (from 3 weeks to 2 months). Bioinformatics analysis of WGSs of representative strains divided them into 4 clusters, which can be considered as separate clonal complexes sharing a number of characteristic genetic markers: 1) 2002-isolates containing one SNP in regulatory rpoS gene; 2) 2007-strains carrying tandemly duplicated preCTX prophage; 3) strains isolated in 2020 in Rostov-on-Don and in 2005, during epidemiological complications in the Kamensk district of the Rostov Region, which had a “hybrid” pathogenicity island including the cluster of type 3 secretion system and the nan-nag region of the VPI-2 island, and 9 SNPs in rpoS gene; 4) 2021- and 2022-strains and a single 2018-isolate containing a 9 bp deletion in vchC collagenase gene. Despite the revealed differences, representatives of all clonal complexes possessed sufficient sets of intact determinants of pathogenicity/persistence factors to realize virulent properties and ability to survive in water bodies. Detection of clonal complexes of potentially pathogenic strains in surface water bodies indicates occasional emergence of favorable conditions for their long-term circulation, which emphasizes the importance of constant monitoring of V. cholerae in the territory of Russia.

108-117 547
Abstract

The aim of the study was to conduct a comparative analysis of the spectrum and antibiotic resistance of secondary pneumonia pathogens isolated in the territories of the Rostov, Tyumen Regions and Khabarovsk Territory against the background of a new coronavirus infection pandemic.

Materials and methods. We investigated sputum samples from coronavirus-positive and coronavirus-negative patients with community-acquired pneumonia from medical organizations using bacteriological method, PCR mass spectrometry.

Results and discussion. The study of the etiological structure of secondary pneumonia agents isolated from patients in medical organizations of the Southern, Ural and Far Eastern Federal Districts has revealed that the dominant cultures in SARS‑CoV‑2 “+” and SARS‑CoV‑2 “–” patients were yeast and yeast-like fungi. It has been found that under diversity of isolated fungi, Candida albicans species prevailed. The bacterial microflora is represented by a variety of gram-positive and gram-negative bacteria, of which Staphylococcus aureus and Klebsiella pneumoniaе were most often present in sputum. It has also been established that even before hospitalization of patients, community-acquired pneumonia could be caused by microorganisms of the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniaе, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.), which are usually considered as polyantibiotic-resistant pathogens of nosocomial infections. Moreover, in coronavirus-positive patients with secondary community-acquired pneumonia, those pathogens were isolated 2–3 times more frequently than in coronavirus-negative ones. Assessment of sensitivity/resistance of isolated strains to antibacterial drugs has revealed a general trend: the majority of the strains, regardless of the type, were characterized by a narrow spectrum of sensitivity, having 3 or more markers of antibiotic resistance. This confirms the necessity and expediency of microbiological support of the patient during the entire infectious process. The most adequate drugs of choice, providing activity against 60–70 % of strains of the Enterobacteriaceae family, are amikacin and cefoperazone/sulbactam.

118-122 364
Abstract

Determination of Vibrio cholerae affiliation to one or another serogroup may meet some difficulties in cases of atypical agglutination with diagnostic cholera sera. The study of genetic determinants that allows for identifying a serogroup is a relevant task in monitoring of surface water body contamination with cholera vibrios.

The aim of the work was to compare the structural organization (quantitative and qualitative gene composition) of LPS clusters in V. cholerae rough variants.

Materials and methods. We used Illumina MiSeq for the whole genome sequencing; SPAdes software (version 3.11.1) for de novo assembly; and blastn (v. 2.5.0) for gene searching. GeneMarkS software was deployed for annotation of the genes incorporated in the clusters; nucmer – for searching homologous sites. Visualization of O-LPS clusters was carried out by means of SnapGene Viewer.

Results and discussion. Strains of V. cholerae rough variants had diverse gene clusters responsible for O-antigen biosynthesis. We have identified three types of O-LPS clusters with different size and number of genes. Unique DNA sites, common to the whole group of V. cholerae rough variants, have not been detected. Two genes present in all rough strains have been defined, but they are not unique for this group of strains and can be found in representatives of other serogroups. For two types of clusters, a region containing the IS‑element, common with V. cholerae O1, has been revealed.

123-131 491
Abstract

The aim of this work was to analyze the spatial and temporal features of the epidemic process dynamics of tick-borne encephalitis (TBE) in Irkutsk Region in 2001–2021.

Materials and methods. The data of the Rospotrebnadzor Administration for the Irkutsk Region, the Reference Center of the Irkutsk Research Anti-Plague Institute, the materials of the state statistical reporting form No. 2 “Information on infectious and parasitic diseases”, and scientific publications were analyzed. The chronological and chorological features of the change in the incidence of TVE have been traced. In the latter case, the administrative-territorial formations (ATF) of the subject were differentiated by epidemiological risk groups over two ten-year periods: 2001–2010 and 2011–2020. At each time interval, the grouping of areas according to the level of TBE incidence was carried out using the calculation of 95% confidence interval. Time sequences of observations were analyzed using the construction of regression equations. Standard methods of variation statistics in the Microsoft Excel were deployed.

Results and discussion. Over the course of the 21st century, the incidence of TBE in Irkutsk Region has been declining. Based on 2001–2010 data, there were no cases of TBE in six ATF, and endemic areas were divided into three groups: with low (15 districts), medium (6) and high (8) incidence of TBE. A separate assessment of morbidity rates was conducted in the administrative center of the entity, the city of Irkutsk. In 2011–2020, the structure of ATF with varying epidemiological risk of TBE underwent a change. Six non-endemic areas, groups of low (12 ATFs), medium (9), high (6) and very high (2) epidemiological risk were identified. The spatial arrangement of high epidemiological risk zones changed, and their area increased. Each ATF cluster with different TBE incidence in 2011–2020 is characterized by the number of TBE cases and the volume of measures to prevent the infection. It is concluded that preventive measures were insufficient in ATF groups of high and very high epidemiological risk.

132-140 539
Abstract

In recent decades, a significant increase in the incidence of tick-borne viral encephalitis (TBVE) and the number of people attacked by ticks has been recorded in the European North of Russia.

The aim of the study was to analyze the dynamics of the TBVE incidence and the number of people who appealed to medical organizations regarding tick bites in the European North of Russia.

Materials and methods. We used the Form No. 2 “Information on infectious and parasitic diseases”, the results of operational seasonal monitoring of TBVE, presented by the Rospotrebnadzor Administrations of the respective territories for our study. Statistical data processing was performed using the Microsoft Excel program. Display of the results on the map was carried out in the geographic information system ESRI ArcMap.

Results and discussion. Combined analysis of the data on the number of cases and TBVE incidence, the number of people who appealed to medical organizations about tick bites and the number of people seeking advice about tick bites per 100 thousand population for the Arkhangelsk Region, the Republics of Karelia and Komi and their municipal districts has been performed. The mean values and gradients of the number of cases, incidence (2010–2020), the number of people who appealed to medical organizations regarding tick bites, and the number of people seeking treatment for tick bites per 100 000 population (2002–2020) have been calculated; maps of average values and gradients constructed. The incidence and the number of cases remain at the high level, exceeding the national average, but have been declining in the last decade. The number of people who appealed to medical organizations and the appealability of the population about tick bites per 100 000 of the population remain at a consistently high level and show no downward trend. The incidence and appealability of the population due to tick bites per 100 thousand of the population is spreading in a northerly direction, covering new territories in the Arctic zone. The main driving force behind the observed epidemic situation in the European North of Russia is the natural processes of climate change.

141-146 2273
Abstract

Extensive spread of tick-borne diseases poses a significant problem for public health and the health of the population living in endemic areas.

The aim of the study was to search, analyze genetic material and identify new viral agents of the Phenuiviridae family in taiga ticks collected in Asian regions of Russia using the method of high throughput sequencing.

Materials and methods. The study involved 1460 taiga ticks collected in suburban areas of the Tomsk, Yekaterinburg and Primorsky Territory. The genetic material isolated from ticks was sequenced using Illumina technology followed by phylogenetic analysis.

Results and discussion. Analysis of the sequencing results made it possible to detect extended nucleotide sequences of the L-gene fragment characteristic of the Phenuiviridae family viruses. We were able to identify 20 nucleotide sequences the length of 250 bp on average in homogenates of Ixodes persulcatus ticks. Eighteen isolates have been identified as members of the genus Uukuvirus and two isolates have been assigned to the genus Phlebovirus, Phenuiviridae family. Phylogenetic analysis has shown that all isolates of the genus Uukuvirus fall under the cluster of Tacheng tick virus 2 belonging to the species Tacheng uukuvirus. They form a separate phylogenetic group which is closely related to two Romanian variants of 2019. Tacheng tick virus 2 was detected in all three surveyed regions of the Asian part of Russia. Two Tomsk isolates of phlebovirus were classified as Sara tick phlebovirus and they clustered with two isolates of phleboviruses from Karelia. Thus, the genetic material of Tacheng tick virus 2 and Sara tick phlebovirus belonging to two genera of the family Phenuiviridae was found in I. persulcatus ticks collected in three geographically different regions of the Asian part of Russia.

147-155 389
Abstract

The aim of the work was to compare the discriminating capacity of the canSNP13 genotyping and MALDI‑TOF mass spectrometry methods based on the results of the study of anthrax pathogen strains belonging to the two main genetic lines A and B.

Materials and methods. 73 Bacillus anthracis strains from the collection of microorganisms of the Stavropol Research Anti-Plague Institute of the Rospotrebnadzor were investigated. Protein profiling was carried out using a Microflex mass spectrometer, data processing – in the environment of the statistical programming language “R”.

Results and discussion. It has been experimentally confirmed that the proposed approach for differentiating proteotypes of B. anthracis strains with a discrimination index of 0.952 exceeds the one for the canSNP typing method and is comparable to the discrimination index for the MLVA31 method. The correlation of the results of strain clustering during typing by MALDI-TOF mass spectrometry and canSNP genotyping reaches 95 % as regards the division into the main genetic lines A and B. The studied strains of anthrax microbe, which mostly fall under phylogenetic groups of lineage A, represent more than a dozen protein profiles, which may be due to differences in the level of protein expression in strains of each canSNP genotype. MALDI-TOF mass spectrometry makes it possible to obtain the results comparable with genetic tests, has a better discriminating capacity compared to canSNP typing, and is easier to perform.

156-163 476
Abstract

The aim of the study was to zone the territory of the Saratov Region using indicators that influence the intensity of epidemic manifestations of hemorrhagic fever with renal syndrome (HFRS), and to assess the risk of infection of people for a differentiated approach to the organization of anti-epidemic measures in natural foci.

Materials and methods. When calculating the intensity of epidemic manifestations of HFRS in the administrative-territorial units (ATUs) of the Region, the indicators that have the greatest impact on the risk of infection were selected: the intensive rate of morbidity among population, the rate of infection of carriers with the HFRS virus, the number of recreational facilities, and the forest cover rate. The paper presents personalized data of HFRS patients, the results of epizootiological monitoring, information about recreational facilities and the forest fund of the Saratov Region. All the data considered cover the period of 2010–2022 for each of the administrative districts of the Region and the city of Saratov. To calculate the intensity of epidemic manifestations, the dimension method and the decimal logarithm were used.

Results and discussion. As a result of calculations, 8 ATU of the Regions have been classed as the territories with the highest intensity of epidemic manifestations and the risk of HFRS infection, with high intensity – 9, with medium – 10 and low – 12. Epidemiological geo-information analysis made it possible to establish that the territories with the highest intensity of epidemic manifestations of HFRS occupy 15.8 % of the area of the region, high – 23.8 %, medium – 28.5 %, low – 31.9 %. Based on the findings of the study, 16 districts of the Region and the city of Saratov were identified as the most dangerous in terms of HFRS infection. Namely these territories that primarily require targeted epizootiological monitoring for early and effective management of preventive activities.

BRIEF COMMUNICATIONS

164-167 447
Abstract

The bivalent chemical cholera vaccine is the only drug for the prevention of cholera registered in the Russian Federation. The vaccine has been produced in glass bottles containing 210 tablets. At the same time, modern trends dictate the need to produce the drug in varying dispensing and more practical packaging for the convenience of the consumer.

The aim of the work was to study the stability of the properties of the immunobiological medicinal product “Bivalent chemical cholera vaccine” with modified filling and in new primary packaging.

Materials and methods. When studying the quality of bivalent chemical cholera vaccine batches, physicochemical parameters, formaldehyde content, specific activity and safety, abnormal toxicity, immunogenicity, and microbiological purity were assessed. Stability in terms of “specific activity” was evaluated using dot immunoassay.

Results and discussion. As a result of this work, the use of several dispensing options and new primary packaging of cholera vaccine has been experimentally substantiated. The stability of the finished vaccine preparation has been established in the “accelerated aging” test and during long-term storage. The possibility of using dot immunoassay with a conjugate based on staphylococcal protein A, labeled with colloidal gold, to monitor the stability of cholera vaccine has been experimentally demonstrated.

ANNIVERSARIES



Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.


ISSN 0370-1069 (Print)
ISSN 2658-719X (Online)