EBOLAS HEMORRHAGIC FEVER

From Big Medical Encyclopedia

EBOLAS HEMORRHAGIC FEVER (Ebola — the river in Zaire) — the infectious disease which is characterized by a heavy current and shown sharp head and muscular pains, diarrhea, the hemorrhagic phenomena and rash.

Flashes E. of l. were for the first time registered in 1976 in rural areas of Sudan (284 cases, 151 of to-rykh ended letalno) and the North of Zaire (318 diseases, from them 280 with a lethal outcome). In Zaire diseases were noted also in 1977. In 1979 in Sudan 34 hard cases of fever are revealed, 22 patients died. Antibodies to a virus — the activator E. of l. are found in residents of Cameroon, the Central African Republic, Nigeria, Sierra Leone, Guinea and Senegal that indicates possible existence in these districts of the natural centers of an infection.

Etiology. The activator — Ebola virus — is allocated in 1976 from blood of the died patient. A virus patogenen for newborn white mice and Guinea pigs. In the intertwined cells of a kidney of a green monkey he actively breeds, but does not cause accurate cytopathic changes. Virions of Ebola virus have the form of crimped yarns; diameter of their 80 — 100 nanometers, length varies, reaching 4000 nanometers. Nukleokai-sid of virion consists of axial filament to dia. 20 — 30 nanometers, the surrounded spiral of a capsid to dia. 40 — 50 nanometers. These educations are put into an outside cover. As a part of virion RNA is found.

Epidemiology. The sick person is a source of a contagium. Tanks of Ebola virus in the nature, despite intensive researches, remain still unknown. Infection of people E. of l. occurs at contact with blood of patients, and also with their excrements, urine, emetic masses, separated nasopharynxes, containing blood. Transfer of a virus with blood of patients at its hit on the injured skin or mucous membranes of healthy people is most probable. Danger of infection of medics, and also the persons who are looking after patients in house conditions is especially high. During flashes E. of l. cases of infection of people at administration of medicines are noted by insufficiently sterilized syringes and needles. All observed cases E. of l. arose in June — November.

Pathogeny and pathological anatomy. At hit in a human body the virus with a blood flow gets into parenchymatous bodies where breeds, and then again passes into blood. Development of hemorrhages is promoted by thrombocytopenia and reduction of content in blood of the factors causing its coagulation (see. Coagulant system of blood).

At the dead from E. of l. find widespread dystrophic and focal necrotic changes in a liver, necrotic changes in a red pulp of a spleen and proliferation of cells of a reticuloendothelium. Necrotic changes are observed also in a pancreas, adrenal glands, a hypophysis, a thyroid gland, testicles and ovaries. In a brain multiple hemorrhages are found, changes in glial elements as proliferative (emergence of glial small knots and sockets), and degenerative (pycnosis and reksis kernels) character are noted. Otlichi-chitelnoy feature patol. process thrombosis of small vessels and development of hemorrhages is.

And m of m at N and t e t at E. of l. it is studied insufficiently.

Clinical picture. An incubation interval from 4 to 16 (7 is more often) days. The onset of the illness is acute, bystry rise in temperature to 38 — 39 °, the indisposition, sharp headaches in frontal and temporal areas, nausea, vomiting are observed. At the same time severe pains develop in breasts, dry cough, various muscle and joints pains which are especially expressed in muscles of lumbar area. Pains in eyeglobes during the pressing are sometimes noted on them. In 2 — 3 days at most of patients razvivav

diarrhea, often very heavy, proceeding about a week etsyatsya; excrements blood, watery with impurity. Diarrhea and vomiting lead to dehydration of an organism (see). On 4 — the 6th day of a disease appears makulopapulezny rash, at first on a face, then extends to a trunk and becomes more expressed on shoulders and hips. In 4 — 5 days on places of rashes the peeling begins. The mucous membrane of an oral cavity usually dry, is often covered with the small sores similar on aphthous (see Afta). Dryness in a throat causes sharp morbidity, especially during the swallowing. The hemorrhagic phenomena — blood in excrements, a hematemesis, bleedings from a nose, a vagina, skin and a subconjunctiva lny hemorrhages develop. At the expressed symptoms of intoxication and the hemorrhagic phenomena there can step death (more often on 7 — the 8th day of a disease). The acute period of a disease proceeds

14 — 16 days. Recovery of patients usually slow, a state improves gradually within several weeks, however exhaustion and weakness remain still a long time. At pregnant women the disease often is complicated by abortion; at men in some cases the orchitis develops.

The diagnosis is made on the basis of data epidemiol. anamnesis (contact with patients E. of l.), wedge, pictures, and also results lab. researches. In blood reveal a leukopenia and thrombocytopenia; ROE is slowed down. The diagnosis confirms detection at a lab. researches of a virus in blood of patients or identification of specific serumal antibodies. In the first days of a disease virus particles in blood can be found by means of a submicroscopy (see), and a viral antigen — by means of indirect reaction of an immunofluorescence (see). For the purpose of allocation of a virus carry out crops of blood on culture of cells of vero (see Cultures of cells and fabrics, the table). Emergence in the course of a disease of specific antibodies in blood of the patient is established by means of reaction of an immunofluorescence by a research of the pair samples of blood serum taken in an onset of the illness and in the period of reconvalescence. In nek-ry cases of an antibody to a virus E. of l. it is possible to reveal already on 5 — the 6th day of a disease.

AA. of l. differentiate with Jlacca-fever (see) and tserkopitekovy hemorrhagic fever (see). Unlike E. of l. Lassa-likhoradka develops gradually, is followed by the expressed pharyngitis and heavy conjunctivitis with periorbital hypostasis; diarrhea at Las-sa-likhoradke is less expressed, than at E. of h.p. tserkopitekovy hemorrhagic fever E. of l. differentiate on the basis of results of virologic and serological researches.

L e h e N and e. The revealed patients (or persons, suspicious on a disease) are isolated and hospitalized in separate chamber. At a possibility of patients place in individual insulating cabins with autonomous ventilation and sterilization of the deleted air.

As means of specific therapy at E. of l. apply immune plasm or blood serum had, the containing specific antibodies. They are entered intravenously in a dose of 250 — 500 ml; if the condition of the patient does not improve, immune plasm or blood serum are entered repeatedly. Appoint the means contributing to normalization of water-salt balance, elimination of intoxication (see. Disintoxication therapy) and hemorrhagic phenomena (vodnoelektrolitny, proteinaceous solutions, solution of glucose, etc.).

The forecast is always serious, the lethality exceeds 50%.

Prevention — early identification and hospitalization of the diseased; an observation within 17 days of the persons who were in contact with the patient. As means of specific prevention E. of l. in some cases (an emergency at a lab. to work with a virus, accidental pricks or cuts at necropsy) use immune plasm or blood serum of convalescents, to-ruyu enter intravenously (250-500 ml).

Bibliography: Hemorrhagic fever

Ebola in Zaire in 1976, Bulletin WHO, t. 56, No. 2, page 213, 1978; Hemorrhagic fever Ebola in Sudan in 1976, in the same place, page 189; Drozdov S. G. and Sergiyev V. P. Protection of ecdemic territories against tropical viral hemorrhagic fevers, M., 1984; With and m p-with about D. I. N X. Viral hemorrhagic fevers of the person, Bulletin WHO, t. 56, No. 6, page 633, 1978; Bowen E. T. and. lake of Viral haemorrhagic fever in southern Sudan and northern Zaire, Lancet, v. 1, p. 571, 1977; Johnson K. M. a. o. Isolation and partial characterization of a new virus causing acute haemorrhagic fever in Zaire, ibid., p. 569; P a t t y n S. o. Isolation of Marburg-like virus from a case of haemorrhagic fever in Zaire, ibid., p. 573; Simpson D. I. H. Marburg and Ebola virus infections, Geneva, WHO, 1977. S.G. Drozdov.

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