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The review presents the data on the development of epidemic caused by Ebola virus in the West-African countries - Liberia, Sierra Leone, Nigeria, Senegal, and Mali. Analyzed is also an epidemic in the Democratic Republic of the Congo, unrelated to the mentioned above outbreaks. Traced have been the chains of transmission and import of the disease (under control and out-of-control) into European and American states. Assessed are the premises for complications faced in the course of epidemic response, and the factors contributing to the wide spread of the infection.

Studied has been systematic approach as regards epidemiological surveillance and control over emergency situations in the sphere of sanitary-epidemiological welfare by the example of Ebola fever epidemic in West Africa countries. Based on the literature data available, analyzed have been measures for EVD surveillance and control, with reference to every stage of epidemiological process (source/ origin, agent, mechanism of transmission, recipient) at various levels of matter organization (global, regional, population, cellular, molecular, and sub-molecular). Following this, put forward have been primary areas for EVD control optimization.

An unprecedented on its scale Ebola fever epidemic, caused by Zaire ebolavirus, has been registered in the territory of West Africa in 2014-2015. The virus quickly spread from the Republic of Guinea into the neighboring countries. Presented are the results of comparative analysis between three Zaire ebolavirus genomes, the complementary DNA of which was obtained from the samples from Ebola fever patients in the Republic of Guinea in 2014. The nucleotide sequences of the genomes received have allowed for identification of phylogenetic affinity to certain references, displayed in the database of NCBI GenBank. General phylogenetic analysis by means of representative sampling has revealed two trends of genome evolutionary development from one and the same ancestral form. The first branch of evolution is represented by a relatively small number of Zaire ebolavirus isolates, disseminated in Guinea. The second one, the most numerous trend, is generated by four variants of Zaire ebolavirus genome, which have been identified starting from May - early June, 2014 in Sierra-Leone, but within a short period of time they have won the whole territory of the country and the neighboring Guinea and Liberia.

The current outbreak of the Ebola fever in West Africa is unprecedented in terms of its scale. As of today, 27550 suspected cases and 11235 deaths have been reported. The outbreak differs from previous epidemics in terms of epidemiological and clinical progression of the disease. The article covers several epidemiological issues related to Ebola virus disease by the example of the Guinean outbreak, which has been plaguing the country since 2014. Given is the preliminary clinical analysis of the medical observations, performed in the Research and Diagnostic Centre of Epidemiology and Microbiology built by RUSAL. Regarded are epidemiological and clinical features of the Ebola virus disease (EVD) in 83 patients, who were admitted to RUSAL Treatment Center since March 6th till June 30th, 2015. In 28 of the patients, EVD diagnosis was laboratory confirmed. The principle assessment criteria are: morbidity rate, lethality index, gender, age, occupation, time since the onset of the disease until hospitalization, an average duration of the stay at the hospital, complaints, symptoms, complications, and the therapy provided.

An estimated scope of measures, aimed at the prevention of Ebola virus disease importation and transmission in the territory of the Russian Federation, targets the maximum level of hazard to the population. It has a complex interagency character, whereby the Federal service for surveillance in the sphere of consumers rights protection and human welfare functions as coordinator and principal executing agency. The measures affect the following areas: regulatory compliance and methodological support, sanitary-quarantine control reinforcement at the entry points on the state border of the Russian Federation, strengthening of anti-epidemic preparedness of the Rospotrebnadzor and public healthcare institutions and authorities, including operational preparedness of the laboratory facilities, information support within the framework of epidemiological surveillance, and involvement in the activities under the international collaboration for epidemic response and control. Practices have been completed as regards series of actions conducted from the time of the case identification and further on; evacuation of the infected and suspected individuals, procedures for sanitary disinfection, interventions in the relation to contact persons, and readiness for anti-epidemic measures performance.

Significant aspect in the provision of anti-epidemic readiness for Ebola fever importation into the Russian Federation is to determine the scope of measures to be undertaken toward individuals who have been in contact with index case. Analyzed have been the published data on the imported case records resultant in the secondary transmission of the disease; measures, performed in relation to contact persons in non-endemic countries; possible mechanisms of transmission; presence of virus in biological material from an infected individual; risk of exposure to virus onboard the aircraft. Based on the results of the analysis of publications, WHO, CDC and Rospotrebnadzor recommendations, with due consideration of the current regulations, put forward is an approximate procedure for individuals who have been in contact with EVD case onboard the plane, including transportation of persons, exposed to the increased risk of infection into a specialized hospital.

Objective of the study was to forecast the scale of the outbreak that would emerge after arrival of persons infected with Ebola virus into the Russian Federation. Initial data for the prediction were obtained from retrospective analysis of hemorrhagic Ebola fever outbreaks registered within the period of 1976-2014, and the spread of the virus in the Republic of Guinea and Mali in 2014. Delays in the identification of a patient and the lack of compliance with control measures may result in secondary disease in 3-5 persons from among the members of the family and the medical staff. Timely diagnostics and strict observance of safety regulations for treatment of patients with fever of unknown etiology will minimize the number of secondary diseases to a single case or none at all.

Taking into consideration experience in utilization of “AmpliSens EBOV (ZAIRE)-FL” in the setting of SAET mobile laboratory complex, carried out has been the improvement of the panel with a view to elapsed time reduction and analytical sensitivity enhancement. It provides for the analytical sensitivity increase up to 200 copies per ml, which is 10 times higher than the previous measurement, that accounted for 2·103 copies per ml. The timing of the assay has been reduced up to 1 h 25 min, which is 25 % less than the time needed for the standard study. Modification of “AmpliSens EBOV (ZAIRE)-FL” panel benefits to the enhancement of epidemiological surveillance activities intended to stop the spread of Zaire ebolavirus in West Africa and prevent its importation into the Russian Federation.

Ebola treatment hospital was constructed within the frames of the West Africa support infinitive of the Russian Federation, in cooperation with the United Company “RUSAL”. Permanent building with bed capacity rated 60 and strict separation of clean area from hazard zone set this medical facility apart from tent camps, which are used by international organizations. For the first time ever, in West Africa, deployed was a strategy of waste decontamination using caustic. It is of note that due to biological safety procedure compliance, no case of nosocomial infection was registered during the whole time of operation. Commissioning of this hospital is an effective mechanism for Ebola virus disease control.