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Problems of Particularly Dangerous Infections

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No 4 (2014)
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https://doi.org/10.21055/0370-1069-2014-4

5-8 738
Abstract
Given is an account of the EVD epidemics that started in the Republic of Guinea in December, 2013 and spread over West African countries within 2014. Established have been the grounds for the Rospotrebnadzor SAET deployment in the Republic of Guinea, objectives, goals and stuffing of the mission, and mobile complex technical performance. Described are the key stages of the work, including the process of integration into the UNMEER. Outlined are priority areas of collaboration with the National Public Health Ministry and international partner organizations. Represented are the results of work on the Ebola fever and other dangerous infectious diseases diagnostics, carried out at the mobile facility. Provided is molecular-genetic characteristics of the Ebola virus.

EPIDEMIOLOGY

9-16 949
Abstract
For the first time ever since the discovery of the Gorno-Altaisk high-mountain natural focus in 1961, registered has been a case of human plague infection. It occurred in the consequence of the grey marmot cutting that was caught in the territory of one of the persistent epizootic regions of the natural plague focus. The outbreak was localized and eliminated following complex anti-epidemic measures, including medical treatment of the patient; identification, isolation and management of the contact persons, both to the patient and marmot; withdrawal and disposal of marmots’ carcasses, obtained during unauthorized commercial hunting; specific and non-specific prophylaxis of the disease. Also for the first time ever received have been the evidences of concurrent circulation of the strains, subspecies Y. pestis ssp pestis and Y. pestis ssp. altaica in the regions of cohabitation of Pallas’ pika (Ochotona pallasi), Siberian souslik (Citellus undulatus), and grey marmot. Specified is the necessity to reconsider the tactics of epizootiological plague monitoring in enzootic territories where circulation of various Y. pestis subspecies is registered.
17-20 751
Abstract
Objective of the study was to develop a method of assessment and forecasting of socio-economic damage inflicted by the outbreaks of infectious diseases using DALY index by the example of Crimean hemorrhagic fever. WHO expert-designed DALY index was adapted for use in the territory of the Russian Federation with due account of GDP values and age distribution among the population. Put forward was a scheme for prognostication of a possible social damage caused by infectious disease outbreak, expressed in the aggregate number of wasted years of productive life and economic loss resulted from GDP decrement. The method developed can be used for forecasting of socio-economic damage inflicted by the outbreaks of infectious diseases and evaluation of effectiveness as regards anti-epidemic and therapeutic interventions. Carried out has been assessment of economic and social losses which resulted from outbreaks of Crimean hemorrhagic fever in the Southern Federal District of Russia inclusive of the data on morbidity rates over the period of 1999-2010. Major economic damage is factored by the labor forces loss consequent to fatal cases of infection. Such a method of prognostication based on DALY index has been implemented in the territory of the Russian Federation for the first time ever.
21-24 1777
Abstract
Objective of the study is to substantiate the possibility to assess local/regional resource capacity needed for a large-scale epidemic response as concerns emerging infectious diseases caused by pathogenic agents of particularly dangerous infections, such as smallpox, anthrax, plague, and Ebola, Marburg, Lassa, Crimean-Congo fevers. Investigations are conducted using a designed at the SRC VB “Vector” universal local epidemic/outbreak (developing within a closed population) model. The results of epidemic dynamics modeling suggest that in case of mass infection of the population in the Novosibirsk Region its resources are well sufficient for tularemia, anthrax, and Marburg and Crimean-Congo fever outbreak control. Response measures for smallpox, plague, Ebola and Lassa fever epidemic control will require additional large-scale federal support.
25-28 646
Abstract
Complex analysis of the data on epidemiology and clinical picture of the tick-borne borrelioses in the territory of the Trans-Baikal Region over the last decade since 2003 to 2012 has demonstrated that there is a distinct upward tendency as concerns its morbidity rates. Spotted have been the potentially hazardous, as regards the infection, areas. Highest incidence rates are registered between May-July among adult men, and erythema form of the disease prevails. Based on the results of molecular-genetic investigation of Ixodidae ticks, for the first time ever in the territory of the Dul’durginsk Region identified has been circulation of Borrelia garinii , and B. afzelii , pathogenic for humans bacterial species of Borrelia genus.
29-35 1453
Abstract
The review contains the results of ecological-epizootiological and epidemiological investigations of plague in the territory of the Socialist Republic of Vietnam in 1989-2012. Studied has been the structure of epizootic triad - carrier-vector-pathogen. There is a low probability of plague foci occurrence in zones of tropical forests and savanna under the conditions of humid subequatorial climate. Main plague agent carrier on the Thai Nguyen Plateau is the synanthropic little rat, Rattus exulans . Specialized fleas species are absent on wild-living rats Rattus genus, as well as mice, and bandicoots, and the abundance of other species is small. It has been demonstrated that all the elements of the parasitic plague system are classified as introduced species. Thereupon it is inferred that plague foci in Vietnam are anthropourgic and are of anthropogenic origin solely. Plague cases in humans across the territory of the country were registered between 1898 and 2002. The most persistent ones functioned on the Thai Nguyen Plateau. Although epizootic activity of the foci in territory of the former endemic provinces has decreased, it is necessary to continue epizootiological monitoring further on in the modern period.

MICROBIOLOGY, DIAGNOSTICS

36-38 749
Abstract
With a view to obtain the data on intraspecific diversity of Hantaviruses circulating in the territory of the Saratov Region, carried out has been molecular-genetic testing of the field and clinical material. Using PCR assay, Hantavirus RNA has been detected in 25 samples obtained from small mammals and 15 blood samples of HFRS patients. Sequencing of 14 hantavirus RNA-isolates from rodents and 3 RNA-isolates from clinical material has made it possible to identify their taxonomic appurtenance to Puumala virus. Phylogenetic analysis of RNA-isolates has revealed that all of them are characterized by high degree of homology in between themselves (99.8 %) and substantial distinction from the known Puumala strains, frequently occurring in Russia (3.6-21 %). Therewith, verified has been circulation of Puumala virus in the territory of the Saratov Region using molecular-genetic techniques. Identified genetic differences of Saratov RNA-isolates, in particular, opens a further prospect for allocation of the sites where people can contract HFRS infection.
39-42 708
Abstract
Objective of the study is to evaluate cholera vibrio resistance to freezing and freeze preservation at -70 °C in the presence of cryoprotectors. The study outlines the results of storage of seven different V. cholerae strains within three-years term in the protective media containing glycerin or lactose (10, 20, 30 % aquatic solutions of glycerin, meat-peptone broth with 10 % of glycerin, a medium with 15 % of lactose and 3 % of gelatin) as cryoprotectors. Demonstrated is the fact that cholera vibrio death occurs during freezing-refreezing procedure and preservation of samples. After three-year conservation the numbers of living cells decrease in all types of media, but to different extent. The highest survival rate in cholera vibrios after freezing-refreezing procedure and freeze preservation in accordance with applicable protocols is observed in lactose-gelatin medium. When using aquatic solution of glycerin as protective medium, optimum turns out to be the cryoprotector concentration equal to 20 %. After three-year preservation at -70 °C all the strains, irrespective of the protective medium composition, retain their basic diagnostically significant phenotypic characteristics. Thus, cholera vibrios can be conserved free from subcultures within three-year term (period of observation) without alterations to their basic diagnostic properties in all tested protective media but at -70 °C.
43-51 797
Abstract
Laboratory diagnostics of plague was carried out in compliance with valid operational guidelines and regulations. But its peculiarity consisted in the performance of diagnostic investigations secondary to antimicrobial therapy with application of preparations characterized by the expressed activity towards gram-negative microorganisms, including the agent of plague (ceftriaxone, ciprolet, and amikacin). The studies revealed that under antibiotic treatment during the early phase of infection the most effective method for the laboratory plague diagnostics was PCR. Based on the results of the assay it was possible to establish not only provisional, but also the final diagnosis in a patient. Obtained was genetic characteristics of the strains isolated from the patient and the marmot, withdrawn at the patient’s place, using techniques of molecular-genetic analysis, in particular PCR, multilocus VNTR, and multilocus and genome-wide sequencing. Thereupon the strains were attributed to antique biovar of the main subspecies of plague agent. In addition, close relation to Y. pestis of the main subspecies isolated in the same focus in 2012 and to the strains from Mongolian Altai and Tuvinian mountain focus was determined based on phylogenetic analysis of the isolates.
52-55 654
Abstract
For the first time ever developed has been the method of identification of genovariants in Yersinia pestis strains belonging to the main subspecies using PCR with hybridization-fluorescent registration of results. A complex of DNA-targets, the most of which are newly detected ones, have been utilized to differentiate between genovariants of antique (0.ANT, 1.ANT, 2.ANT, 4.ANT), medievalis (2.MED, 2.MED0), and orientalis (1.ORI) biovars. Application of these targets in PCR with hybridization-fluorescent registration of results provides for a rapid, effective and reliable classifying of the strains of the genovariants, circulating in various geographical regions. Efficacy of the method has been validated via analysis of 110 Y. pestis strains, isolated in the territory of the Russian Federation, neighboring countries and beyond, including 37 strains of antique, 53 strains of medievalis, and 20 strains of orientalis biovars.
56-60 1049
Abstract
Middle-East respiratory syndrome is a human disease caused by a new coronavirus. In December, 2012 WHO published draft regulatory document on diagnostics of the virus. It was recommended to use two methods of disease diagnostics - two-phase reverse-transcription real-time PCR and enzyme immunoassay. The first phase of the PCR-diagnostics should include reverse-transcription real-time PCR targeted on the genome fragment upwards of upE. The second (control) PCR-test may be alternatively targeted within the bonds of the genome, its target being non-crisscross with upE gene. It should include sequencing of, at least, a segment of one of the viral genomes and comparative analysis of the obtained sequence along with the like ones deposited in the GenBank. Enzyme immunoassay is retrospectively used for virus-specific antibody detection in convalescents’ blood sera. Examined are the key specifications of the methods for the detection of ethiological agent or specific antibodies to it, and WHO methodological recommendations in case of Middle-East respiratory syndrome diagnostics.

BIOTECHNOLOGY, IMMUNOLOGY

61-64 557
Abstract
Experimentally substantiated is the possibility to apply tangential ultrafiltration for desalting antigen components of the tableted bivalent chemical cholera vaccine. Specified are the technological parameters of the process. It is demonstrated that the properties of choleragen-anatoxin (produced by Vibrio cholerae strain 569B Inaba) and O-antigens (produced from V. cholerae 569B Inaba and M-41 Ogawa strains) obtained using the designed methodology are as efficient as the ones manufactured using certified procedure and satisfy regulatory requirements. Experimentally substantiated technology for the desalting of antigen components of chemical cholera vaccine provides for the reduction of the time elapsed up to 5-6 hours from the original 3 to 4 days. It also allows for the manufacturing under controlled conditions. This hard-ware controlled method of desalting has been implemented into the vaccine production practice.
65-67 686
Abstract
Objective of the research was to use immunoblotting for studies of epitope targeting in monoclonal antibodies to 200 kDa Burkholderia pseudomallei antigen, which are synthesized by hybridomas-producers from the two collections in the laboratory of immunodiagnostics and biotechnology at the premises of Volgograd Research Anti-Plague Institute. Employed were 8 typical strains of melioidosis agent with the complete antigenic structure. Antigen preparations were separated by means of denaturating vertical electrophoresis in 12 % polyacrylamide gel with 0.1 % sodium dodecylsulfate. During the process of cell-replication, 12 hybridomas-producers were given preparative amounts of monoclonal antibodies to 200 kDa Burkholderia pseudomallei glycoprotein. Following that, immunoperoxidase conjugates were manufactured. Epitope targeting of monoclonal antibodies was evaluated using immunoblotting. With the help of vertical electrophoresis identified was the presence of several mandatory major components contained in the antigen complexes of the salt-water and formamid B. pseudomallei extracts . Differential staining substantiated glycoprotein origin of certain antigen components. Immunoblotting with the stated above antigen preparations revealed epitope targeting of a number of monoclonal antibodies to 200 kDa antigen of melioidosis agent; demonstrated were the differences in their specific interaction with biopolymers which form part of the antigen specter. Those differences were characteristic of hybridomas-producers belonging to different collections, as well as of particular strains of B. pseudomallei.
68-70 1569
Abstract
It is known that S-form Brucella causes allergic transformation in a macroorganism, which is manifested as delayed-type hypersensitivity reaction. This capacity in atypical variants (L-forms) is under-investigated. It is demonstrated that corpuscular antigen in B. abortus 19BA vaccine and thermoextract prepared from B. abortus I-206 in S-form when threefold administered cause marked sensibilization; while corpuscular antigen and thermoextract produced from Brucella in L-form, and thermoextract from Brucella in S-form in case of one time administration do not have such an effect on leucocytes of white mice.
71-74 793
Abstract
Carried out was comparative study of the sorption properties in polymeric enterosorbent - chitosan, and its specific modified analogue obtained through absorption of anti-toxin immunoglobulins onto the soluble chitosan template. It is determined that soluble chitosan and its specific counterpart express high sorption activity in relation to cholera toxin, thus making lower its initial concentrations. Equilibrium adsorption capacity of the chitosan and its modified variant increase with the raise of initial cholera toxin concentration in the solution. Cholera toxin extraction rate was identified under static conditions. Adsorbate substance recovery rate was registered in the progression. In the course of experiments proved was modified sorbent specific sorption efficiency, occasioned by the presence of the active component in the analogue composition - namely, anti-toxic anticholeraic immunoglobulins. The data obtained are of the importance for further development of specific anticholeraic enterosorbent.

BRIEF COMMUNICATIONS

75-77 668
Abstract
equals 520÷610 mcg/mouse. Sensitivity of the animals to the stated above LPS forms’ effect when affected by D-GalN is by two orders greater, and as for LPS of the virulent strain is by three orders. Concurrently, differences in toxicity properties in the original (LPS37) and conformationally altered (LPS37-MT) LPS-forms in both of the tested Y. pestis strains drop out of the equation completely.
78-79 766
Abstract
Designed has been a computer program “Epidemic potential of natural plague foci in the Russian Federation” applied for the automatized evaluation of the epidemic hazard level of natural plague foci in relation to the population residing on the territory of them. This software optimizes management decision making via provision of the Heads of the Rospotrebnadzor organizations with the comprehensive current data on the sanitary-epidemiological situation on plague across the whole territory of the natural foci in Russia, and by enhancing the quality of the visual data display, which are essential for the decision making in the sphere of biological safety provision. In consequence of integration into “Deductor” software program, counted value of epidemic potential for any location of the natural focus territory can be ranked correspondently using colorimetric scale (from red up violet color, for maximum and minimum rating, respectively). The program is designed on the base of Arc GIS Platform to be introduced into the automatized information analysis system for the provision of biological safety in the constituent entities of the Russian Federation.
80-82 738
Abstract
Carried out has been electron-microscopic investigation of dynamics of interactions between Yersinia pseudotuberculosis, Yersinia pestis cells and specific bacteriophages in vitro. Identified have been peculiarities in morphological manifestation of the interactions. Determined are morphometric characteristics of the bacteriophages utilized in the experiment. It is demonstrated that after 40 minutes of co-incubation of Y. pseudotuberculosis with specific bacteriophage emergence of persisting forms of microbial cells is observed, while in case of EV strain infecting with Pokrovskaya bacteriophage, this phenomenon is not detected.
83-84 648
Abstract
Reported is the event of detection of Anaplasma phagocytophilum in Ixodes angustus ticks using gene-diagnostic technique. Anaplasma DNA is identified in one of the nine samples of ixodic tick imago collected from common species of rodents in the suburbs of Magadan. The data obtained may be indicative of the existence of natural granulocytic anaplasmosis focus in the south of the Magadan Region where the agent persists in enzootic cycle: small mammals - Ixodes angustus.

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