Issues of Scientific and Practical Support of Anti-Epidemic Activities in the Course of Ebola Virus Disease Epidemic Response in West Africa

Consideration is given to the experience of cooperation between the Russian Federation and the Republic of Guinea in the matter of Ebola fever response. Outlined are the challenging issues regarding scientific support of preventive activities. Provided is a brief characteristic of Pasteur Institute of Guinea as a unique platform for research activities. Covered are the legal aspects of collaboration and priority areas for the development of common initiatives in the sphere of epidemiological monitoring. Identified are the stages of material reinforcement and medical stuff capacity building, including training of specialists with a view to the establishment of effective system for epidemiological surveillance

Epidemiological Peculiarities of Ebola Virus Disease Epidemic, 2013-2015 in West Africa Countries

Represented are the results of analysis of the on-going EVD epidemic, 2013-2015 in West Africa countries. Identified have been epidemiological peculiarities, the principal ones of which are: the scale of epidemic transmission; social factors of widespread occurrence; registration of EVD cases in the new territories of the African continent - West Africa (Guinea, Liberia, Sierra-Leone); genetic distinction between Ebola virus and the strains of the same virus, species Zaire ebolavirus, that caused previous outbreaks; prevalence of febrile syndrome over hemorrhagic; high risk of infection with EVD among the healthcare workers. Most probable carriers of Ebola virus may be fruit-bats of the three species - Hypsignathus monstrosus, Myonycteris torquata, and Epomops franqueti. Outlined are the key stages and factors of EVD epidemic development

Detection of Crimean-Congo Hemorrhagic Fever Virus Markers in Samples of Ixodes Ticks Collected in the Territory of the Republic of Guinea

Objective of the study. This work was carried out to identify markers (antigen and RNA) of CrimeanCongo hemorrhagic fever (CCHF) virus in samples from ticks, collected in all landscape-geographical areas of Guinea: Lower, Middle, Upper and Forest, to obtain up-to-date data on the distribution of the pathogen in the country.Materials and methods. Total of 4276 specimens of 8 species of ticks collected in 2016–2019 in the territory of the Republic of Guinea were studied, which were compiled into 1406 samples. Ectoparasites were collected from livestock animals, dogs, and small mammals. Viral antigen was detected using enzyme immunoassay (ELISA). The presence of RNA of the CCHF virus was determined by reverse transcription polymerase chain reaction (RT-PCR).Results and discussion. As a result of the studies, the antigen of the CCHF virus was detected in 21 samples (1.5 %), and RNA – in 37 (2.6 %). All samples, in which the viral antigen was detected, contained RNA of the CCHF virus. Positive results were obtained in samples from all geographical areas of the country. The main vectors and reservoirs of the pathogen in Guinea are ticks of the species Rh. sanguineus, Rh. geigyi, Rh. annulatus and Am. variegatum. The data obtained confirm the previously available information on the possibility of the pathogen circulation in this region and determine the need for further study of the spread of the CCHF virus in the territory of the Republic of Guinea

Studies of Ebola Virus persistence in the Body Fluids of a Patient at Advanced Stages of Convalescence

At present EVD epidemic, which claimed the lives of more than 10000 people, is still underway in West Africa Countries. Promptness and quality of laboratory diagnostics, alongside with delivered anti-epidemic measures predetermine efficacy of Ebola response operation. Due to a lack of means for the specific prophylaxis and treatment of the disease, asymptomatic patients are discharged from hospitals, based on criteria recommended by WHO, which might be insufficient. Viral RNA is detected in different clinical samples taken from the patients even at the advanced stages of convalescence, which requires essential investigation of peculiarities of Ebola persistence in various biological fluids. The article contains the data on the studies of biological samples, obtained from a female patient diagnosed with Ebola virus disease, applying various methods and techniques

Experience of Application of the ELISA Method for Detection of Antibodies to Ebola Virus during the SAET Team Work in the Republic of Guinea

The aim of the work was to develop a kit for detection of IgM and IgG antibodies to Ebola virus in ELISA.Materials and methods. Ebola virus strain Zaire H.sapiens-wt/GIN/2015/Kalidie-Kindia-1022 grown on cell culture was used as antigen.Results and conclusions. The kit was used by the Rospotrebnadzor SAET team in its work in Guinea while investigating cases during Ebola fever epidemics. It was established that specific IgG antibodies persisted in Ebola fever survivors for 2 years. Application of this kit in the laboratory diagnostics permits ELISA to become the main and confirmatory laboratory method of Ebola fever detection

Use of antivenoms for the treatment of envenomation by Elapidae snakes in Guinea, Sub-Saharan Africa

Background: In Guinea Elapids are responsible for 20% of envenomations. The associated case fatality rate (CFR) ranged 15-27%, irrespective of treatment. Results: We studied 77 neurotoxic envenomations divided in 3 groups: a set of patients that received only traditional or symptomatic treatments, and two other groups that received either 2 or 4 initial vials of Antivipmyn (R) Africa renewed as necessary. CFR was 27.3%, 15.4% and 17.6%, respectively. Although antivenom treatment was likely to reduce CFR, it didn't seem to have an obvious clinical benefit for the patients, suggesting a low treatment efficacy. Mean delay to treatment or clinical stages were not significantly different between the patients who recovered and the patients who died, or between groups. Interpretation of these results is complicated by the lack of systematic studies under comparable conditions. Of particular importance is the absence of assisted ventilation, available to patients in all the other clinical studies of neurotoxic envenomation. Conclusion: The apparent lack of clinical benefit may have several causes. The hypothesis of a limited therapeutic window, i.e. an insufficient formation of antigen-antibody complexes once toxins are bound to their targets and/or distributed beyond the reach of antivenom, should be explored

INDICES OF IMMUNE RESPONSE IN PATIENTS OF FALCIPARUM MALARIA IN REPUBLIC OF GUINEA

Malaria in the Republic of Guinea is the main cause of morbidity and lethality. It takes the first place in number of all visits in medical service (30–40%) and is the main cause of hospital death. One records annually more than 8 millions malaria cases, and about 60 000 children deaths. Results of study of immune response changing on different disease phases in treatment of autochthon population and immune status of Europeans are presented. It was shown that immunity status (cellular and humoral) in population of Guinea (an endemic country on falciparum malaria) differs from one in Europeans living in tropics. During light forms of malaria one records an increase of T-lymphocyte and IgG number, whereas in grave cases one observed the acute decrease of these indices. The essential increase of B-lymphocyte number does not depends from gravity of disease and from malaria treatment. It was established that appearance of LSA1-41 antibodies was in a more degree in adult patients than in children. The positive correlation between IgM and IgG was established in adult patients as in children

MEASLES VIRUS IMMUNITY LEVEL STUDY IN PARTICULAR POPULATION GROUPS OF THE REPUBLIC OF GUINEA WITHIN THE FRAMEWORK OF GLOBAL MEASLES ELIMINATION PROGRAM. REPORT 1

Measles remains one of the main reasons for child mortality in developing countries and periodically leads to the emergence of large outbreaks in different countries. This problem became especially urgent after WHO accepted the strategic plan to fight against measles. The plan has set the goal to decrease measles on a global scale. In 2010–2011 the large outbreaks of measles were registered on the African continent: in the Democratic Republic of Congo in the south of Africa, in Nigeria and in some other African countries. In the Republic of Guinea vaccination against measles is carried out singly to children aged 9 months. In 2014–2015 the increase of measles incidence was noted. Materials and methods. Using ELISA 22 blood serum samples of healthy adult Guineans aged 24–71 and 136 blood serum samples received from children and adults — the patients of hospital in the town of Kindi (Republic of Guinea) have been examined. The clinical samples were received in 2015–2016. The following test systems were used: the test systems produced by Euroimmun Medizinische Labordiagnostika AG (Germany): «Anti-Measles Virus ELISA (IGM)», «Anti-Measles Virus ELISA (IgG)»; «Avidity: Anti-Measles Virus ELISA (IgG)», and also ELISA Vector-Best IgM-measles test system (Russia). Results and discussion. Only one out of 22 examined healthy individuals hasn’t revealed IgG-antibodies to measles virus. The quantitative titre test of IgG-antibodies, and also their avidity among other 21 individuals testify experiencing measles in the recent or remote past. Having examined 116 blood serum samples of hospital patients in Kindi for IgM-measles-antibodies, the measles case with a 2.5-year-old child has been retrospectively revealed. Having examined 130 blood serum samples for IgG-antibodies to measles virus, 12.3% of seronegative to measles individuals have been revealed. All examined individuals aged 23 and older were seropositive to measles virus, and 60% of them had high antibody titres. The antibodies to measles virus were absent or were defined in low titres among 76.2% of people under 22, which can demonstrate violations of planned child vaccination due to the Ebola outbreak. In order to decrease the risk of emergence of large measles outbreaks in the areas, free from Ebola virus transmission, WHO recommends to conduct mass anti-measles vaccination campaigns