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Problems of etiology, taxonomy and nomenclature offiloviruses, epidemiology, morbidity with a little-known by Russian medics especially dangerous exotic infectious disease - Ebola fever are examined. Significant distinguishing features of 2013 - 2015 epidemic in West Africa were de- tected - along with its unprecedented length, a decline did not take place as in previous outbreaks, neither causative agent virulence, nor infectivity of the infection during multiple generations from human to human. Literature data analysis allowed to assume that in the process of epidemic focus formation Ebola virus changes its properties and cyclically passes through several successive in- terconnected phases: an initial reservation phase in unknown ecosystems - animals, either plant, soil or water; intermediate phase of epidemic spread with primary acquisition of high virulence for humans, and then its decline; final stage of hidden circulation of causative agent that is ap- athogenic for humans. This hypothetical chain of natural phases' transitions of Ebola virus allows to explain and link together phenomenology of this causative agent - rapid fall of virulence and infectivity for humans in foci in dynamics of epidemic outbreaks, quite a high population immunity in nosoareal of the causative agent in Africa, that contradicts the established understanding of its high lethality for humans.

Acceptable means of therapy and prophylaxis for most of the especially dangerous viral hemorrhagic fevers to present date are lacking. Analysis of the state of this problem shows that creation of a new generation of etiotropic preparations requires selection of additional targets for their effect that may be based on the use of molecular-biological features of pathogenesis of these infections. Literature data analysis has shown that during filovirus infection non-structural and structural proteins of the causative agents serve as pathogens during direct damaging effect of the virus and secondary immune reactions that in general pervert cell and humoral components of immunity converting its destructive effect on cells and tissues of the macro organism. Selection of promising approaches of antiviral therapy is possible based on molecular-biological analysis of interaction of micro- and macro organism with isolation of the most vulnerable for the effect of causative agent aggression factors.

Analysis of data of the available literature on epidemiology of Bolivian hemorrhagic fever, manifestations of human disease, biological properties of the causative agent and development carried out abroad of means and methods of diagnostics, prophylaxis and therapy of this infection that presents a potential threat for the population and economy of the Russian Federation in case of introduction of the causative agent is presented.

Aim: Optimization of conditions of quantitative evaluation of Argentine hemorrhagic fever causative agent., Materials and Methods: Junin virus (XJ P37 strain) was obtained from National collection of viral hemorrhagic fever causative agents of the 1st pathogenicity group of the 33rd Central Research Testing Institute. Junin virus (XJ P37 strain) culture with biological activity of 5.2 lg PFUxm(-1) was used in the experiments. Vero B, 6619-1(D) and GMK-AH-1(D) were obtained from collection of cell culture of the Research Scientific Centre of the 33rd Central Research Testing Institute. Calculation of biological activity of Junin virus during titration in cell cultures was carried out by Kerber method with modification by I.P. Ashmarin., Results: During incubation for 4 - 7 days after the infection of cell monolayer the determined biological activity was 4.4 - 6.4 lg PFUxml(-1); the size of the formed negative colonies--(1.5 +/- 0.5) mm., Conclusion: The conditions of quantitative evaluation of Argentine hemorrhagic fever were optimized by negative colonies method (using 5 - 7 day Vero B cell culture monolayer with staining of monolayer on day 5 of secondary incubation, recording of results at day 7 after the infection).

In the last quarter of century virus of Rift valley fever (RVF) sharply extended its distribution by moving from Africa to Asia and evolving from low- to high pathogenic for humans causing severe hemorrhagic disease, practically equaling in this respect with some members ofa group of extremely dangerous pathogens. Morbidity and epidemics of RVF are analyzed. Evolution of epidemic development of the infection is examined. Necessity of development of means and methods for diagnostics, prophylaxis and therapy of RVF is underlined.

Features of the Argentine hemorrhagic fever are described in the review. Epidemiology, etiology, clinical presentation and pathogenesis of the disease are examined. Special consideration is given to the features of the pathological agent of Argentine hemorrhagic fever--the Junin virus. Features of the disease diagnostics are indicated--virological and serological studies, immunochemical and molecular-biological methods of identification of the pathological agent and antibodies against it. Approaches to etiotropic therapy of this disease and vaccination are examined. Based on the foreign experience perspective guidance for the creation of the system of protection of the population of the Russian Federation against Argentine hemorrhagic fever are presented.

Features of hantavirus pulmonary syndrome are considered in the review - zoonosis natural focal polyetiological viral infection, that is characterized by lung injury. Etiology of the disease, main characteristics of the agents, epidemiology, contagiousness, pathogenesis, clinical presentation of this pathology are examined. Laboratory diagnostics, therapy and prophylaxis ofhantavirus pulmonary syndrome are described.

Development of the theory and practice of building and maintenance of collections of reference cultures of pathogens strains is actual in conservation of a biodiversity, and as for maintenance with standardized superfine starting materials fundamental and applied researches in fields of microbiology, an immunology, biotechnology, ecology, and biosafety. Various approaches to taxonomy of viruses, and also definition of concepts "strain" and "species" are discussed in the article. Formulations of the concepts most conforming to museum collections activity are given. The methodology of collecting pathogens, including fifteen-year experience of maintenance of the National collection of hemorrhagic fever viruses belonging to group I of pathogenicity, is summarized. The systemic approach is suggested as a basis of methodology of collecting. Selection of pathogen species and their specific strains according to purpose and on the basis of complex study of their biological and other characteristics, as well as standardization and unification of methods of pathogens maintenance and preparing on their basis working materials, diagnostic kits and other preparations, create a real basis of optimization, unification and continuity of the subsequent applied researches. The offer about formation at the state level of a new independent direction--pathogens collecting with establishment of federal centers based on pathogens' classes has been made.

In this review modern data on dangerous and particularly dangerous viral haemorrhagic fevers caused by a group of viruses belonging to the families of phylo-, arena-, flavi-, bunya- and togaviruses are presented. Morbidity rates and epidemics caused by Marburg virus, Ebola fever virus, Lassa fever virus, Argentinian and Bolivian haemorrhagic fever viruses, dengue haemorrhagic fever virus, Crimean haemorrhagic fever virus, Hantaviruses are analyzed. Mechanisms of the evolution of the epidemic manifestation of these infections are considered. The importance of the development of tools and methods of diagnosis, rapid prevention and treatment of exotic haemorrhagic fevers is emphasized.