Epidemic Complications Research Articles

НЕБЕЗПЕЧНА ДИНАМІКА ІНФЕКЦІЙНОЇ ЗАХВОРЮВАНОСТІ В УКРАЇНІ

Мета роботи – проаналізувати інфекційну захворюваність в Україні за останні роки і обґрунтувати причини епідеміологічних ускладнень.Вказано на основні загрози активізації інфекційних хвороб в Україні та причини несприятливої епідеміологічної ситуації, що склалася на сьогодні. Наведено динаміку захворюваності та смертності від цих хвороб за період з 2010 по 2011 рр. Перелічені хвороби, які супроводжувалися у 2016 р. приростом захворюваності в абсолютних числах і з розрахунку на 100 тис. населення. Зроблено акцент на почастішання епідемічних спалахів. Обґрунтована важливість проблеми внутрішньолікарняних інфекцій і необхідність їх повнішої реєстрації. Показана доцільність внесення змін у список орфанних інфекцій, затверджений МОЗ України.Висновок. В Україні зростає інфекційна захворюваність на ряд нозологічних форм і почастішали епідемічні ускладнення, що потребує більших профілактичних, протиепідемічних і клінічних зусиль. Першочергові заходи слід спрямувати на усунення (послаблення) названих причин такого стану.Ключові слова: інфекційна захворюваність, смертність, приріст захворюваності, епідемічні спалахи, внутрішньолікарняні інфекції, орфанні інфекції.

DETERMINATION OF PHYLOGENETIC RELATIONSHIP OF YERSINIA PESTIS STRAINS FROM NATURAL PLAGUE FOCI OF THE CAUCASUS BY MULTI-LOCUS VNTR-ANALYSIS

Determination of the degree of phylogenetic relationship of Yersinia pestis strains iso- lated from the territories of natural foci of plague from the Caucasus using VNTR-typing by 25 loci (MLVA25). 26 strains of Y pestis from Russian natural foci of the Caucasus were used in the study. 25 loci of tandem repeats in Y pestis genome by Le Fleche scheme were used for execution of multi-locus VNTR-analysis. Deciphering of nucleotide sequences was carried out in automatic sequencer ABI 3130 Genetic Analyser. Analysis of confinement of clusters to certain territories, objects and time of isolation of strains was carried out. using Arc GIS 10.1 program. Groups of MLVA25-types of various levels of discrimination were formed: clusters, groups and subgroups. Clusters were formed by strains ofvarious taxonomic membership: main and subspecies of Y pestis. Subgroups reflect membership of strains in certain foci, and MLVA25-types - the degree of genetic relationship. Genetic <<portraits>> of plague causative agents obtained using MLVA25-types circulating in various natural-focal territories allow to solve problems ofboth theoretical and practical character: from interpretation of microevolution processes to the search of the source of infection and ways of its spread during possible epidemic complications.

ANTHRAX IN THE ASIAN PART OF THE RUSSIAN FEDERATION. COMMUNICATION 2. UP-TO-DATE EPIZOOTIOLOGICAL AND EPIDEMIOLOGICAL SITUATION IN SIBERIA AND AT THE FAR EAST (1985–2016)

7201 stationary hazardous as regards anthrax points (SHAP) and 557 anthrax burial places are registered in Siberia and the Far East. Epizootiological and epidemiological situation for anthrax in the Asian part of the Russian Federation is characterized at present by uneven geographical distribution and predominance of old non-manifested shaps (98.9 %), and epizootic outbreaks with epidemic complications (82.5 %). In the Siberian Far North and four southern areas of the region it remains hazardous. Reduction of livestock population in 1990s lead to agricultural animals morbidity decline, thus morbidity among deers dominated (80.2). Sporadic pattern of the epidemic process was observed. The majority of patients were unvaccinated rural population (97.5 %), males (77.5 %), ablebodied citizens infected during constrained slaughtering (90.5 %). Meat and meat products were main transmission factors (96.4 %). Cutaneous anthrax prevailed. Anthrax outbreak in the Yamalo-Nenets Autonomous District in 2016 outlined the necessity of effective interdepartmental interaction and optimization of normative regulation on disposal of fallen cattle and condition of anthrax burial places.

CHARACTERISTICS OF STATIONARY HAZARDOUS AS REGARDS ANTHRAX AREAS IN ALTAI TERRITORY IN THE MODERN PERIOD

Objective of the study is to comprehensively evaluate and forecast the development of epidemic process in case of anthrax in Altai Territory. Materials and methods. The data on stationary hazardous as regards anthrax areas (SHA) were obtained while analyzing cadastres of SHA in Altai Territory, as well as the reference book “Cadastre of stationary hazardous as regards anthrax areas in the Russian Federation”. Statistical and report forms from the institutions of the Rospotrebnadzor and Federal Service for Veterinary and Phytosanitary Surveillance in Altai Territory, and from Altai Plague Control Station were used for retrospective analysis of anthrax morbidity rates in Altai Territory over the period of 1953–2015. Laboratory investigations of field and clinical samples were carried out in compliance with Methodological Regulations 4.2.2413-08. Results and conclusions. Anthrax remains topical issue for Altai Territory as there are 1262 stationary hazardous areas situated in here, as well as registered animal and human infections. The density of such areas in Altai Territory is 7.5 times higher than across Siberia. Factors for the SHA formation and their sustainability are soilclimatic aspects of the region. The majority of hazardous areas are found in steppe and forest-steppe zones, predominantly along the cattle-driving paths. In Altai Territory, between 1953 and 2015, out of 1262 registered areas, 314 ones manifested epidemiological activity, including 246 new ones. Human infections were reported in 36 districts (59.1 %), while in 21 (34.4 %) – morbidity rates exceeded the territorial average. Cumulative dynamics of anthrax morbidity as regards livestock in Altai Territory in 1953–2015 showed downward trends. Complex evaluation of the situation and forecast of epidemic process development, employing composite index – epizootiological index and zoning of the territory according to the risk of epidemic complications – allows for the improvement of managerial decisions with the view to adequate anti-epidemic measures.

Molecular epidemiology of vibrio cholerae - development of the algorithm for data analysis of whole genome sequencing

The algorithm of the comparative analysis of genome-sequencing data on toxigenic strains of Vibrio cholerae, obtained on different technological platforms was developed. The algorithm includes the establishment of sampling and analysis of genomes and 1929 SNP, localized in the open reading frames. The result of the analysis of genome-sequencing indicates to the presence of several waves of importation of toxigenic strains into the territory of the Russian Federation. As noted relationship strains caused the epidemic process in 1994 in Dagestan and in the Ukraine, and they are clearly discriminated from strains isolated after 2000. The strains have caused epidemic complications in Dagestan in 1994, are distributed between three different clusters, which allows to suggest the presence of at least three independent drifts in cholera in the Republic ofDagestan during the epidemic in 1994, and the presence of strains from Bangladesh and Mozambique in these clusters may indicate to the possible origin of the source of infection. So the flash in 2001 in Kazan, probably is caused by a "Nepalese" strains. Recent events in Haiti epidemic were caused by strains of "Haitian Group", which in the same period of time often were isolated in our country but have not received distribution. In our opinion, the developed algorithm can be used to develop a single unified approach to the study of the molecular epidemiology of cholera in the Russian Federation.

Population Migration as a Risk Factor of Transboundary Importation of Dangerous Infectious Diseases in the Siberian and Far Eastern Federal Districts

Some kinds of external migration of the population are considered as a risk factor for occurrence of the epidemic foci of dangerous infectious diseases in Siberian and Far Eastern Federal Districts of the Russian Federation. The role of tourism and labour transboundary migration in formation of epidemic complications for dangerous infectious diseases is shown. The urgency of threats for the disease importations representing danger to humans including influenza caused by a new virus subtype, measles, cholera, poliomyelitis and Dengue fever etc increases in the given regions.

Multilocus sequence typing of Vibrio cholerae strains with differing pandemic importance

Allelic polymorphism of the housekeeping genes (dnaE, lap, recA, pgm, gyrB, cat, chi, and gmd) from Vibrio cholerae strains of differing epidemiological significance (n = 41) isolated in Siberia and the Far East during the seventh cholera pandemic was studied. Irrespective of time and source of isolation, all toxi-genic strains isolated in the period of epidemic complications were characterized by an identical allelic profile and belonged to the same sequence-type. Nine sequence types were detected in nonepidemic isolates. Their dendrogram clustering was associated with the serogroup and, in some cases, with the territory and time of isolation. The structural heterogeneity of the nontoxigenic V. cholerae housekeeping genes was, in most cases, caused by synonymous nucleotide replacements (Dn/Ds < 1). This indicates the prevalence of negative selec-tion at the analyzed genome regions of V. cholerae. The revealed differences in the housekeeping gene struc-tures of V. cholerae of different epidemiological significance can be regarded as evidence of different direc-tions of evolution of these strain groups.

Epidemiological Situation on Zoonotic and Natural-Focal Infectious Diseases in Siberia and Far East in 2013; Prognosis for 2014

Based on the reference data on monitoring of natural-focal infections, collected from the institutions of the Federal service for surveillance in the sphere of consumers rights protection and human welfare, estimated are the morbidity rates for natural-focal and zoonotic diseases in Siberia and Far East Region within a period of 9 months, 2013. Established is the scope of laboratory investigations as regards anthrax, brucellosis, tularemia, yersinioses, leptospirosis, borreliosis, rickettsiosis, and a number of viral infections. It is determined that high waters in the Amur River region did not have any considerable impact on the epidemiological situation in 2013, however in 2014 epizootic and epidemic complications are expected to take place, for the prevention of which enhanced package plan is being implemented. The situation on tularemia in the Khanty-Mansi Autonomous District, and brucellosis - in the Republic of Tyva and Trans-Baikal Region is still tense.

A retrospective macrorestrictive analysis of Vibrio cholerae eltor strains isolated under epidemic complications in the Russian Far East

A retrospective study of the clonal structure of 24 Vibrio cholerae eltor strains isolated during epidemic complications in the Russian Far East was carried out on the basis of a macrorestrictive analysis of Vibrio cholerae eltor genomic DNA using NotI and SfiI endonucleases. It was found that clonal (by amplification profiling data) toxigenic strains (n = 23) were characterized by variability of the NotI/SfiI-generated restriction profiles. The V. cholerae eltor isolated during an outbreak in the city of Yuzhno-Sakhalinsk were differentiated into four pulse types, with one dominating type detected in 76.5% of the strains. A separate NotI/SfiI-restriction profile was characteristic for the isolates from Primorskii krai. A nontoxigenic strain formed a separate dendrogram line from the toxigenic strains on the basis of the PFGE-pattern structure. The use of macrorestriction analysis was shown to be effective for deep characterization of the V. cholerae population structure and for ascertainment of molecular-epidemiological regularities in the territorial distribution of certain V. cholerae clones.

Concerning the Measures for Stabilization of Epidemiological Situation in the Territory of the Amur Region under Conditions of Emergency

A large-scale rainfall flooding in the territory of the Amur Region formed the foundation for dramatic aggravation of epidemiological situation, in that which concerns outbreaks of diarrheal disease, activation of epidemic processes associated with enteroviral infection and a number of natural-focal infectious diseases, as well as emergence of anthrax cases both among animals and humans. Basic anti-epidemic and preventive activities under emergency situation included: epidemiological monitoring over infectious and non-infectious morbidity among the population; microbiological and virusological laboratory surveillance of the ambient environment objects and water supply sources; sanitary-hygienic monitoring of the habitant living environment; immunization of the population depending on epidemiological indications; planning and implementation of disinfection, deratization, and disinsection procedures in the flood-stricken areas. Successful cooperation between the Rospotrebnadzor local agencies, Irkutsk Research Anti-Plague Institute SAET, regional health institutions and other organizations involved, in a challenging situation at the flooding site, made it possible to avoid serious epidemic complications among the population of the Amur Region.

Sanitary-Hygienic and Microbiological Monitoring over the Water Supply Sources and Surface Water Reservoirs during Natural Disaster in the Amur-River Territory

Emergency situation in summer 2013 due to flooding of extensive areas of the Russian Amur-River territories (including residential areas with different level of development of public services and amenities, agricultural land, sites of cattle grazing and stock-keeping) resulted in the increased microbiological, virologic and physical-chemical load upon water reservoir ecosystems. The results of monitoring over water supply sources, quality of drinking water and surface reservoir waters in the devastated territories were analyzed by the specialists from Rospotrebnadzor and specialized anti-epidemic teams No. 1 and 2. Complex approach presuming increase in extent and frequency of the examinations, performance of operative epidemiological analysis along with daily adequation of preventive and anti-epidemic measures allowed for taking control over the situation and to avoid epidemic complications as regards acute water-borne intestinal infections.

Microevolution of cholera agent in the modern period

To carry out comparative molecular genetic analysis of highly pathogenic atypical Vibrio cholerae strains biovar El Tor, isolated in the territory of RF, in order to determine micro-evolutionary alterations of cholera agent in the modern period. 38 clinical strains have been examined by means of polymerase chain reaction, sequencing and MLVA-analysis. The selected strains were isolated at different periods of time during cholera epidemic complications and differed between each other in virulence. It is demonstrated that new variants have emerged in the course of short-term microevolution. Their genome structure and function differ from those of all previously known strains. The genome alterations have been caused by point mutations in ctxB u tcpA genes associated with virulence and located in CTXΦ prophage and pathogenicity island VPI-1 respectively, as well as by the extended deletion in pandemicity island VSP-II. Presented is the dynamics of genome structure and function alterations in modern strains. The discovered genomic alterations in the new variants of the agent evolved in the process of microevolution are indicative of their epidemic potential enhancement and probability of virulence potentiation.

Conditions for Virus Circulation and Premises for Natural West Nile Fever Foci Formation in the Territory of the Saratov Region

Local climate change (rise of mean temperatures and amount of precipitation, prolongation of frost-free season) triggers further distribution, and increase in numbers of animals – carriers and vectors of West Nile fever virus in the territory of the Saratov region. Based on the results of ecological-epizootiological monitoring (2006–2012) traced out have been the species composition, abundance dynamics, and character of distribution of birds habitant in aquatic and anthropogenic complexes, mosquitoes and Ixodidae ticks. Investigated are possible causes of West Nile fever nosoarea expansion, related to ecology of migrating birds wintering in Africa. Persistent circulation of the virus in intra-zonal inundated biocoenosis facilitates formation of secondary natural foci of West Nile fever and factors into epidemic complications as regards this particularly dangerous vector-borne infection. On the basis of analytical data concerning hydrographic network density, fauna structure, population numbers of birds and mosquitoes – potential carriers and vectors of WNF, epizootiological and epidemiological surveillance, designed has been expectation-driven forecasting map chart which illustrates possibility of sustainable WNF foci formation in various territories of the Saratov region.

Epidemiological Situation on Natural Focal Viral Infections in the Territory of the Stavropol Region

Landscape-geographical and climatic peculiarities of the Stavropol Region, high abundance of mosquito and ticks, the diversity of wild mammal and bird species, developed agriculture and infrastructure create favorable conditions for circulation of arboviruses and hantaviruses, emergence of cases of viral infections, which sometimes cause serious epidemic complications. CHF natural focus actively functions in the territory of the Stavropol Region at present. Detected is presence of West Nile fever, tick-born encephalitis, Batai fever agents and specific antibodies, as well as hemorrhagic fever with renal syndrome agent.

Optimization of Epidemic Survey and Epizootics Prognostication in Kyzylkum Autonomous Plague Focus in Modern Conditions within Uzbekistan

Kyzylkum autonomous plague focus, the large part of which is situated on the territory of the Republic of Uzbekistan, has always been distinguished as regards periodic development of acute extended epizootics and occurrence of epidemic complications. Epidemic survey includes the wide reconnaissance with visual evaluation of epizootiological factors and material collection out of fresh pellets for serological analysis. In case of discovery of carriers carcasses, suspected as plague infected, the collection of samples into spiritus in view of their further PCR analysis is carried out.