Advanced Laboratory Methods for Detecting Yellow Fever Pathogen

Yellow fever is an acute infectious disease of viral nature, the causative agent of which is vector-borne –is transmitted through the bites of infected mosquitoes. Massive epidemics caused by the yellow fever virus are observed in the countries of Africa, South and Central America annually. Imported cases are also registered in non-endemic territories. The review presents the currently available data on the distribution, structure and classification of the yellow fever virus, the identification of its genetic variants depending on the geographical distribution, as well as modern methods of detection and identification of the pathogen in samples taken from sick and dead people. It considers the possibility of using virological, immunoserological and molecular-genetic methods for the diagnosis of yellow fever in different periods from the onset of the disease and in retrospective studies. The lists of diagnostic drugs of domestic and foreign production for the detection of agent markers (antigen, RNA), as well as specific antibodies of IgM and IgG classes, approved for use on the territory of the Russian Federation, are provided. The relevance of further development, improvement and introduction into laboratory practice of reagent kits that allow to detect the yellow fever virus in samples from sick people in a short time, with high efficiency and specificity is demonstrated. This will help to establish a diagnosis promptly and conduct timely anti-epidemic measures, as well as to determine the level of the population stratum immune to the pathogen in endemic regions and evaluate the effectiveness of immunization for the vaccinated contingent

New Data on the Dissemination of the Nipah Virus (<i>Henipavirus. Paramyxoviridae</i>) and Methods of its Indication and Identification

Nipah virus (Nipah virus, NiV) is a representative of the genus Henipavirus of the Paramyxoviridae family, the causative agent of a dangerous infectious disease with a wide range of clinical manifestations – from an asymptomatic (subclinical) form to severe encephalitis with fatal outcome. Despite the fact that the disease caused by this virus is registered only in the countries of Southeast Asia, the possibility of importing the pathogen to non-endemic territories is not excluded. Also, this pathogen is able to infect not only a large number of people, but also animals, causing serious diseases and significant economic damage, posing both, a medical and veterinary problem. This review presents the data available in the modern press on the structure and classification of the Nipah virus, possible cycles of its transmission, spread, methods of indication and identification in clinical and biological material, as well as the effectiveness of their use depending on the timing of the onset of the disease and available commercial diagnostic and preventive drugs

Prospects For the Use of Loop Isothermal Amplification in the Diagnosis of Particularly Dangerous Infectious Diseases Caused by the Viruses of the Pathogenicity Group I

Dangerous viral infectious diseases pose a serious threat to human life and health, as their uncontrolled spread leads to the development of major outbreaks and epidemics. Rapid and accurate detection of the pathogen is an essential component of the fight against infectious diseases. This review is devoted to loop-mediated isothermal amplification (LAMP), which is one of the simplest and most reliable methods of molecular-genetic research that meets modern requirements. The simplicity of the analysis and registration of the obtained results, which is necessary under conditions with minimal laboratory capacities, makes it possible to consider this type of diagnostic technology as the most promising, which allows us to identify genetic markers (DNA or RNA) of pathogens of dangerous infectious diseases in the shortest possible time. Objective of the review is to summarize and systematize the data available to date on the use of LAMP for detecting RNA of dangerous infectious diseases caused by the Ebola,Marburg and Lassa viruses. The paper discusses the basic principles of the loop isothermal amplification reaction, the components that make up the reaction mixture and are used for the analysis, as well as methods for detecting the results obtained. When studying the information available in the literature sources about the advantages and disadvantages of LAMP, it is shown that in many cases, isothermal amplification is not inferior in sensitivity and specificity to the main molecular-genetic diagnostic methods currently used. Modifications that can be used for accelerated diagnostics of RNA-containing viruses are also considered

Feasibility Study on Hemotransfusion Transmission of West Nile Fever Virus in the Territory of the Saratov Region

In order to identify the risk of hemotransfusion transmission of West Nile virus in the territory of the Saratov Region, carried out has been analysis of 1760 blood sera and 270 blood samples from donors residing in the Region, intended to detect markers, indicating recent infection with the virus. Consequently, identified have been IgM and/or low-avid IgG suggestive of a late contact with the agent. The data obtained demonstrate the feasibility of realization of hemotransfusion mechanism for West Nile virus transmission in the territory of the Saratov Region in a particular season. It is planned to continue investigations, applying 2 analytical methods: ELISA and PCR, with individual testing of biological material from each donor

Detection of Specific Antibodies to Arboviruses in Blood Sera of People Living in the Territory of the Saratov Region

This work continues serological surveys previously carried out in the territory of the Saratov Region in order to detect specific antibodies to arboviruses. Presented are the results of analysis of blood sera of humans and agricultural animals collected in different climatic zones of the Saratov Region. Sera were examined for the presence of IgG immunoglobulins specific to the viruses Tahyna, Batai, Sindbis, tick-born encephalitis, CCHV, and West Nile fever

Experience in Genome Analysis Use in SAET Mobile Complex Facilities

Described is the first-ever experience in genome analysis use in SAET mobile complex facilities, obtained during the XXVII World-wide Summer Universiade in Kazan, 2013. Carried out was 16S rRNA sequencing of Salmonella enteric strain isolated from an infected. For that matter, employed was “MicroSEQ 500 16S rDNA Bacterial Identification Kits” (Applied Biosystems, USA), which allows for sequencing of DNA fragments (500 bp) of 16S rRNA gene in the bacteria under investigation

Prevalence of Arboviruses in Vietnam

For many years, arbovirus infections have been a global health problem and one of the urgent threats to the sanitary and epidemiological well-being of the population. Climatic conditions, species diversity and abundance of vectors, epidemiological and demographic factors are of fundamental importance for the emergence and persistence of natural foci of arbovirus infections. In the Socialist Republic of Vietnam (SRV) and other countries of the Asia-Pacific region, the most complex epidemiological situation is observed in regard to a number of arboviral infectious diseases transmitted by mosquitoes, inter alia to dengue fever. In this review we analyzed the literature data to identify the features of the circulation of some arboviruses in Vietnam, such as dengue virus, Zika, Chikungunya, Japanese encephalitis virus, Dabie virus, and the routes of their transmission and spread. It is shown that the climatic, ecological, epidemiological and demographic conditions existing on the territory of Vietnam contribute to the spread of pathogens of many arboviruses. Areas of more active circulation and ways of spreading pathogens of arbovirus infections have been identified. Based on the data obtained, it is necessary to conduct annual epidemiological and epizootiological survey of the territory of the SRV in order to identify markers of pathogens and determine the boundaries of natural foci of arbovirus infectious diseases which will enhance and increase the effectiveness of preventive and anti-epidemic measures

Management of Diagnostic Investigations at the Premises of Specialized Anti-Epidemic Team Mobile Complex at the Time of Running Mass Events

Laboratory support of epidemiological surveillance plays a significant role in the provision of sanitary-epidemiological welfare of the population at the time of preparations to and carrying out public events. Taking into consideration the increment of load upon the laboratory facilities of the Rospotrebnadzor institutions and general medical-and-prophylactic establishments, there emerges a need to deploy specialized anti-epidemic teams. By the example of management of the laboratory investigations in SAET mobile complex during XXVII World-wide Summer Universiade in Kazan, 2013 and G-20 Summit in Saint-Petersburg, 2013 formulated have been the basic principles of organization and algorithms of diagnostic work at the premises of laboratory facilities of SAET mobile unit deployed in order to provide for sanitary-epidemiological welfare of the population at the time of running public events

Introduction of New Preparations for Gene Diagnostics of Dengue Fever and Cholera

Presented is the information on technical and medical trials of new generation preparations for gene diagnostics of Dengue fever and cholera, based on the multiple factor analysis. Application of these preparations makes it possible not only to detect pathogen but also to carry out its expedited identification in accordance with epidemiological significance and taxonomic status

Development and Testing of the Method for the Detection of Lassa virus RNA, Based on real-Time Polymerase Chain reaction with reverse Transcription

Abstract. Objective of the study was the development of a method for the detection and quantitative analysis (realtime RT-PCR) to identify genetic markers of Lassa virus - LASV-Fl. Materials and methods. We utilized all the available in the GenBank database (https://www.ncbi.nlm.nih.gov/genbank/) Lassa virus sequences that have been aligned to identify conservative sites applying the BioEdit 7.2.5 software package (IbisBiosciences, USA). To test the developed PCR kit, the control panel of Lassa virus RNA and pseudo-viral particles, 27 viral strains belonging to different fami­lies, as well as 37 serum samples from patients with feverish diseases selected in medical institutions of the Republic of Guinea in 2016-2018 and 55 samples of organ suspensions from multi-spiked mice were used. Results and discussion. The analytical sensitivity of the method varied from 103 copies/ml to 105 copies/ml and had 96.4 % diagnostic sensitivity, while the analytical and diagnostic specificity was 100 %. It is shown that the developed technique can be successfully introduced into practice for the detection of Lassa virus in the Republic of Guinea, using various types of material from small mammals, including whole blood and organ suspensions of M. natalensis, as well as samples of human blood sera collected 3-7 days after the onset of the disease. It is also suggested that this method can be used for strains of Lassa virus, common not only in Guinea but also in other endemic areas, but this fact must be confirmed in further studies