Ebola haemorrhagic fever ( Ebola ) - Causes, Symptoms and Treatment .MF .

August 12, 2017 17:52 | Infectious Diseases

situation on quarantine infections, which include Ebola, the world is saved tense.The last epidemic of the disease in Africa (2014) once again attracted attention because of the high transmissibility among people, lightning-fast development of clinical symptoms and high mortality, reaching 70% of the number of cases on average.

GL Ebola, transportation patient

Ebola haemorrhagic fever (GL Ebola, Ebola Haemorrhagic Fever, EHF) - acute quarantine natural focal disease caused by the Ebola virus, transmitted by rodents and monkeys to man, and from man toman, characterized by predominantly heavy current and high mortality.

urgency of the problem is global in scale.

Firstly, it is an opportunity the epidemic spread of natural foci (Africa) to other continents by migration in the incubation period (the period from the date of zaazheniya before the onset of symptoms).
Secondly, the GL refers to the Ebola quarantine infections, ie, is highly infectious and therefore very important in preventing the spre

ad of infection is given sanitary and epidemiological measures.
Third, the rapid development of symptoms, the severity of its manifestations, as well as the high mortality rate (50-90%) puts the disease in the leading place among the causes of death from epidemics and requires urgent remedial measures during the initial identification of the patient.

historical and geographical information on the Ebola virus Ebola virus

opened recently - only some 38 years ago.The first outbreak of Ebola GL is dated 1976 year, whereas in Zaire (now the Democratic Republic of the Congo) 318 sick people, 280 of whom (88%) died.Disease was named from the name of the Ebola River in the north of Zaire, which is near and registered the first cases of fever.Almost simultaneously, an outbreak of Ebola GL and Sudan - 284 people got sick and died in 151 (53%).In the subsequent flash periodically recorded in the Sudan, Kenya, Zaire, Gabon.Scientists have proved the virus circulates among animals and inhabitants of Cameroon, Nigeria, Guinea, Senegal, Sierra Leone, the Central African Republic.Note that all this natural foci of the Ebola virus, which is present in the reservoir of infection (rodents, monkeys), favorable conditions for the existence of the virus, and also recorded with some frequency incidence among men.We must not forget that it is not excluded introduction of infection to other continents by migration (North and South America, Europe, Asia).

GL Ebola, geographic distribution

latest outbreak of Ebola GL registered in 2013-2014, when a December 2013 there were cases of the disease and deaths in Liberia, Guinea, Sierra Leone.Also, a number of cases GL Ebola emerged in Nigeria, Congo.During the outbreak became ill several doctors volunteer humanitarian mission, US natives, UK.WHO Official data released on 09/08/2014, the data on 3944 cases, including 2097 cases (53%) of death.WHO assesses the situation as an emergency.Well underway testing experimental drugs and prepare the conditions for the clinical testing of vaccines developed against Ebola virus.

Causes GL Ebola

Pathogen - GL Ebola - Ebola virus belonging to the family of Filoviride (filoviruses).Ebola virus genome represented single-stranded RNA, comprising 7 virion structural proteins.Morphologically, the virus is a straight filament with rounded ends virion diameter of about 100 nm and a length of 650 to 1400 nm.

Ebola

Ebola virus is sufficiently resistant to high temperatures: at 60 ° inactivated within 30 minutes when exposed to UV radiation - within 2 minutes, dez.sredstva (formalin, acetone, chloroform) destroysvirus after one hour of exposure.Low temperatures resistant virus as well: at -70 ° C. is maintained for a long time (up to 1 year).

There are several subtypes of Ebola virus:

1) subtype Zaire (EBOV) - is responsible for the largest outbreak of GL Ebola causes outbreaks with the highest mortality rate from 59 to 90%, is characterized by severe, the first outbreaks associated with the usereusable instruments for parenteral interventions without adequate treatment;
2) Sudan subtype (SUDV) also characterized by the emergence of a large number of fever outbreaks, mortality rate lower than that of Zaire virus - 54-68%;
3) subtype Bundibugyo (BDBV) become pathogenic to humans in 2007, when during the year were recorded cases of GL Ebola among human in Bundibugyo,
4) subtype Tai Forest (TAFV) pathogenic for chimpanzees,
5) Reston subtype (RESTV) considered to be a relatively new virus, is often subclinical forms, light enough for the disease to humans weakly pathogenic and mainly represents a danger for green monkeys, recorded outbreak among pigs in China, in the Philippines.
first three subtypes have been the cause of large outbreaks of Ebola in Africa.Potip Reston is often asymptomatic disease, found in China, the Philippines.

source of infection. primary reservoir of the Ebola virus in nature is unknown (it is in a natural ecosystem, there is a basic cellular host of the Ebola virus).The natural reservoir of the Ebola virus biological Africa are carnivorous bats - several kinds of fruit bats (Hypsignathus monstrosus, Myonycteris torquata, Epomops franqueti). Accordingly, the area for these types of fruit bats, and is spread by the Ebola virus .The final hosts are primates (African Green Monkey - Cersopithecus aethiops, macaque - Macaca fascicularis), pigs (Ebola Reston virus subtype) and the person for whom the virus is highly pathogenic.In primates, the disease can occur inapparent (completely without symptoms).

Source Ebola infection - fruit bats and monkeys

sick people and sick animals are a danger to others.All infectious patient isolation - nasopharyngeal contents, urine, blood, vomit, sperm, and others. patient becomes infectious from the first day of the onset of symptoms. virus is released about 3 weeks after onset of the disease.However, describe the isolation of the virus from the seminal fluid to 7 weeks after the patient's recovery.During the incubation period (ie before the onset of disease symptoms) the patient is not contagious.During the outbreak of recorded cases of secondary and tertiary and more human infection from the sick patient, that is, multiple nosocomial infection (first infected the second, the third second, third fourth ...).

possible virus circulation in the area of ​​tropical forests in conditions of high humidity.These are the countries of Central and West Africa (Congo, Nigeria, Sierra Leone, Liberia, Kenya, Sudan, Gabon, Senegal and many others).

mechanism Ebola virus infection. In order to talk about the possible ways of infection, you need to remember that the virus has the variety and selection of ways themselves - infectious blood, nasopharyngeal mucus, urine, vomit, mucus genitals, bronchial secretions, secretions of the gastrointestinal tract, seminal fluid.The most dangerous material is a patient's blood.

leading mechanism of infection is contact-household, which means infection after direct contact with the secretions of the patient GL Ebola animal or human. This mechanism is carried out by a joint power, general-use household items, direct contact with the secretions of a patient by patient care, decontamination discharge, laboratory research, as well as direct contact with the secretions of animals (chimpanzees, gorillas, carnivorous bats in the endemic region).Infection is possible in contact with the Ebola virus in the mucous membranes and the skin of a person in violation of their integrity, which is why the GL Ebola is considered highly contagious illness.

the airborne transmission mechanism Ebola virus (airborne route) is not proved.This is evidenced by the absence of infection in individuals who are in the same room with the patient, but do not have close contact with them.

contagious index in the hearth varies from 20% (by brief contact) to 80% or more (after prolonged and close contact).

Ebola refers to diseases spread by blood-sucking insects without.

risk for infection with Ebola GL:

1) Medical personnel having direct contact with the patient (patient care, conducting medical procedures, examination of the patient).
2) Personnel carrying out the identification and capture of infected animals (eg, monkeys).
3) Immediate family members of Ebola sick GL (nursing in the absence of treatment to the doctor, special funeral rites).
population susceptibility to the virus Ebola GL is quite high.

Immunity after undergoing disease-resistant, durable.Repeated cases are rare.

Pathogenic action of the Ebola virus on the human body.

Atrium - damaged skin and mucous membranes (mouth, mucous membrane of the eye), which gets the Ebola virus.The whole nature of the disease is largely determined by the tropism of the virus - that is the favorite, "target cells", which is the endothelium of blood vessels, the pluripotent stem cells in bone marrow.

When infected Ebola occur following processes:

1) changes in the place of introduction of the virus is not present, from the place of the entrance gate of infection the virus enters the regional lymph nodes, where it multiplies (called the incubation period, clinical symptoms during this period is not);
2), the virus enters the blood (viremia, toksinemiya), a symptom of which the patient is fever and intoxication, at this stage, the person becomes contagious to others;
3) defeat of the endothelium of blood vessels in different organs and systems, characterized by the development of multiple organ disease (liver, kidneys, myocardium, spleen, lungs, and others);in bodies marked necrosis, hemorrhage, inflammatory changes;
4) the development of thrombus syndrome or disseminated intravascular coagulation (bleeding and hemorrhage).

Symptoms GL

Ebola incubation period (the period from infection to onset of symptoms) can last from 3 to 21 days.precursors period is absent.

• Start sharp: the patients concerned about the high febrile temperature (up to 39-40 °), chills, severe headache, back pain, muscle pain, joint pain.In the first 3-4 days of illness resembles influenza.
• At 3-4 day can appear vomiting, sometimes repeated, diarrhea, abdominal pain without a specific localization, blood in the stool.
• Later there is a dry cough and stabbing chest pain, signs of dehydration develop.
• Within 4-5 days after the onset of the disease the patient's condition becomes critical, extreme drowsiness, and changes of the psyche.Dry mouth and throat, sores on the back of the throat, characteristic of a sore throat.
• On the 5-7th day of illness appears maculopapular rash, after the disappearance of which is marked peeling of the skin.

GL Ebola, rash

• Hemorrhagic syndrome manifests itself as a hemorrhagic rash (from point to major hemorrhage), nosebleeds, bloody vomiting, gastrointestinal bleeding, uterine bleeding, miscarriage in pregnant women occurs.

GL Ebola DIC

The general analysis of blood: leukocytosis, anemia, reduced platelet counts.

In case of a favorable course of the disease recovery occurs within an average of 2-3 weeks.The rehabilitation period (up to 3 months after recovery), patients may feel weakness, fatigue, nervousness, loss of hair.

Death occurs usually on the 2nd week of the disease on the background of hemorrhage and shock (
intoxication and dehydration).

Complications GL Ebola heavy enough and lead the majority of the patient's death: DIC with the development of major bleeding (gastrointestinal, fallopian) and bleeding into vital organs (brain, adrenal glands), hypovolemic shock (extremedehydration), toxic shock (at the height of the fever develops neurotoxicosis or infectious-toxic encephalopathy, which is manifested by edema of the brain, loss of consciousness, stop the functions of vital brain centers).

Prognosis is poor - GL Ebola mortality in up to 90% (ranging from 50 to 90%).

Diagnostics GL Ebola

Primary diagnosis is clinical and epidemiological:

1) leading news item is carefully assembled epidemiologichseky history (living in an endemic area, stay in it or coming from a region where cases of GL Ebola recorded; contact with febrile patientsin the endemic area, contact with animals in Africa).
2) Clinical data (acute onset, rapid progression of the disease symptoms, the presence of clinically fever, severe intoxication, hemorrhagic syndrome, signs of destruction of many organ systems - liver, kidneys, lungs, myocardium, and others).
3) The differential diagnosis should be carried out with other haemorrhagic fever (Marburg, Lassa, yellow fever and other hemorrhagic), typhoid fever, malaria, typhus, cholera, meningitis and hepatitis.

Final diagnosis is carried out with the help of laboratory tests (all the specific studies are conducted in specially equipped laboratories to work with especially dangerous infections, because all the material from the patient are high biohazard):

1) Laboratory tests to detect antigen Ebola virus.
2) The reactions to detect antibodies to the Ebola virus.
To solve these problems using neutralization reaction (pH), enzyme immunoassay
(ELISA), polymerase chain reaction with reverse transcription (RT-PCR), electron microscopy, immunosorbent assay enzyme-binding with the capture antibody (ELISA), isolation of the Ebola virus in cellcultures.

GL Ebola lab work

Treatment GL Ebola

Therapeutic activities include a number of basic principles:

1) Organizational-regime activities - immediate hospitalization of patients in
hospital infection, rapid isolation of the patient, complianceepidemiological safety - all personnel should be instructed on the mechanism of transmission, work in special suits with maximum protection of the skin and mucous membranes (Anti suit type I, there are now modern versions), chemically and physically light diet for a patient, sufficient water and drinking regime.

GL Ebola suit

GL Ebola patient care

2) Medical event.So far (2014) specific treatment GL Ebola is not made public,
there are experimental drugs that are clinically tested at the time of the last outbreak in Africa (2014), and there are positive results.

All therapeutic measures to reduce pathogenetic and symptomatic treatment:
maintaining vital functions of the patient's body by detoxification (reduction of fever and intoxication with intravenous detoksiruyuschih cocktails, prevention of shock), rehydration (replenishing lost fluid volume), platelet correctionhemorrhagic syndrome, hormone therapy, immunotherapy, and more.

Extract patients conducted with full clinical recovery and 3hkratnyh results of virological examinations, but no earlier than 21 days from the onset of the disease.

Prevention GL Ebola

1) Conducting control activities to prevent the spread of infection in endemic foci
within and beyond its borders, as well as prevention GL Ebola spread to other continents.

infectious disease doctor Bykov NI