EBOLA VIRUS: MODERN STATE OF PROBLEM

The diseases, which is called Ebola virus (earlier – hemorrhagic fever Ebola or Ebola) – the acute viral highly contagious natural indirect disease, which is characterized by severe run, high lethality, expressed intoxication, dehydration, damage of blood-vessels in many organs with development of hemorrhagic syndrome.

On 26, March, 2014 WHO informed about outbreak of Ebola that took place in three south-western districts of Guinea (Gekedu, Masenta and Kissidugu). Despite the fact that WHO warned all countries that border on Guinea about necessity to strengthen the epidemic supervision for diseases that are accompanied by symptoms of hemorrhagic fever, in some weeks the disease spread to the capital – Conakry, as well as neighboring Sierra Leone and Liberia. As of 23, July, 2014 the total amount of cases of Ebola disease that appeared in these three countries is 1,201, including 672 lethal cases (3.4).

Due to high contagiousness, lethality, numerous ways for transmission of infection from human to human, the level of great outbursts, including hospital-acquired ones, Ebola disease is referred to those infectious diseases that are subjected to regulation of international medical sanitary rules 2005. The extraordinary variety of clinical implications during the first days of disease complicates its early diagnostics. Viruses of Ebola disease may be used as biological weapon as they may easily be transferred by air and may potentially cause to a great number of infections and deaths. The lethal index at outbursts of disease is 90% (1.2).

The natural host of virus is carnivorous bats from family Pteropodidae.

The infecting agent of Ebola is RNA-containing virus that belongs to family Filî viridae. The virus contains the glycoprotein, which may be found in the dissoluble form and causes to the sharp increase in penetrability, vascular massive bleedings. Virus has five different subtypes: Zaire (EBOV), Sudan (SUDV), Tayi Forest (TAFT), Bundibudjio (BDBV) and Reston (RESTV). Only 4 of them affect a human. Reston subtype is characterized by symptom-free or easy course at humans.

Ebola virus is passed at direct contact with the blood, secretions, organs or other liquids from organs of infected human. The funeral ceremonies, at which the people, being present, have the direct contact with the dead body, may play the significant role in Ebola virus passage. Health care workers are often infected with Ebola virus during care for patients as a result of close contacts with absence of corresponding measures of infectious control and proper barrier methods on care. Ebola virus is found in many liquids (blood, defecation, urine, saliva, nasopharynx discharges, and sperm) that stipulate the contact, sexual ways. Adults mostly often fell ill. The outbursts of infection often have the hospital-acquired character with infection first of all the medical staffs, who serve patients. The infection is passed at direct contact with the blood, biological liquids and tissues of infected people. The cases of secondary and tertiary spread of infection among staff of hospitals, as well as the transfer of infection through the tools, contaminated with the blood, were observed (1, 2, 3).

Ebola fever is not spread on vector-borne basis (by insects), as well as through food and water.

Ebola fever is characterized by acute start with symptoms of expressed intoxication, quick increase of temperature up to 38-39°C during 5-7 days, strong headache, pain in joints, muscles. A little later there appear the dry cough, dry mouth and throat irritation, acute pain in the breast. On 2-3 day of the disease there appears the stomachache, nausea, diarrhea, as a result of which the development of dehydration is possible. In some cases the eruptions may appear, firstly on the face, then on the breast, which are spread to other parts of the body. Since 3^rd-6^th day of the disease there appears the hemorrhagic syndrome, which is manifested by massive extravasations, bleedings from gums, nose, blood in vomit masses, defecations, uterine bleeding, etc. The death may occur on the 2nd week.

The causative agent of Ebola fever is referred to the Ist group of especially dangerous pathogens (Ukraine) or to the IVth risk group due to modern international standards of WHO, the work with it requires the provision of maximum level of protection (1).

The specific treatment is not developed. The methods of treatment are directed to reduce the symptoms of diseases.

The specific prevention (vaccination) of disease is not developed. The proper medical isolation of patients and prevention from contact of medical workers and other people with the virus is the most efficient way for prevention from transfer of disease from human to human. Patients with Ebola fever are subject to immediate hospitalization to the boxes of the unit with preservation of strong anti-epidemic regime. The support staff shall work in maximum protective clothes with preservation of strong barrier methods of care. It is also necessary to pay the special attention to the proper disinfection of medical wastes and biological liquids of patients (1, 2, 3, 4).

At present moment the clinical researches of agents for treatment and prevention of Ebola disease are held in some directions: combination of monoclonal antibodies, capable to block some viral proteins, protective sera and vaccines.

WHO and its partners – Global network GOARN, CDC, UNICEF, Pasteur Institute in Dakar, and others continue working together to accelerate the control over this outburst. On 01.08.14 WHO Director General Margaret Chen, in the presence of presidents of Guinea, Sierra Leone and Liberia in Conakry declared about start of large-scale program with the budget of USD 100 millions to overcome with the outburst of Ebola diseases. Due to the most optimistic forecasts, it can be done at least in half a year (3.4).

At present moment (10.08.14) WHO does not recommend to introduce any restrictions to trips and trade in relation to the countries, where the outbursts of diseases are fixed – Liberia, Guinea and Sierra Leone but the government of Kenya partially closed the borders for tourists from Guinea, Liberia and Sierra Leone but the government of Liberia closed most frontier points, hoping to stop the disease (3, 4).

Infectious diseases (textbook) (edited by O.A. Golubovska) – Kyiv: VSV “Medicine”. — 2012. — P. 778 — 12 colored pages inclusive (O.A. Golubovska, M.A. Andreychyn, A.V. Shkurba, etc.)

Netesov S.V., Filoviridae – mystery of XX century – Soros educational journal. – ¹8. – 1999 – p. 25 – 29.

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