Ebola virus disease, formerly known as Ebola hemorrhagic fever (GLE), is a serious, and in most cases fatal, disease in humans. Mortality in GLE epidemics can reach 90%. HLE epidemics occur mainly in remote villages in West and Central Africa, near tropical rainforests. The virus is transmitted by wild animals and spreads from person to person. The natural host of the Ebola virus are the fruit bats of the Pteropodidae family. Severely ill patients require intensive symptomatic treatment. There is no authorized etiotropic treatment or vaccine for humans or animals.

The Ebola virus was first identified in 1976 when two outbreaks of the disease occurred - in Nzar, Sudan, and Yambuku, in the Democratic Republic of the Congo (DRC). In the latter case, the village was located next to the Ebola River, from which the disease takes its name.

The Ebola virus belongs to the family of Filoviridae (filovirus), which also includes two other species: Marburg virus (Marburgvirus) and Lloviu virus (Cuevavirus) There are five subtypes of Ebola virus:

Unlike species from Reston and the Thai forest, species from Bundibujio, Zaire and Sudan have been associated with large outbreaks of GLE in Africa. A species of Ebola Reston virus found in the Philippines and the People's Republic of China can infect people, but to date no case of illness or death has been reported.

The Ebola virus is transmitted to people in close contact with the blood, secretions, organs or other body fluids of infected animals. In Africa, documented cases of human infection resulting from the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelopes and porcupines have been found dead or sick in humid forests.

Second, the Ebola virus spreads in human communities by spreading from person to person through close contact (through violations of the skin or mucous membranes) with the blood, secretions, organs, or other bodily fluids of infected people. , as well as by indirect contact with media contaminated by such fluids. Funeral rites, in which those present at the funeral have direct contact with the body of the deceased, can also play a role in the transmission of the Ebola virus. Transmission of infection through infected seminal fluid can occur up to 7 weeks after clinical recovery.

Health workers are often infected with the Ebola virus when they treat patients with GLE and patients with suspected GLE. This occurs as a result of close contact with patients with insufficiently strict adherence to infection control standards.

Among workers who have come into contact with monkeys and pigs infected with the Ebola Reston virus, several infections have been reported that were clinically asymptomatic. Thus, the Restola Ebola virus is less capable of causing disease in humans than other types of Ebola virus.

However, the available evidence only applies to healthy adult men. It would be premature to draw conclusions about the health effects of this virus on all population groups, such as people with weakened immune systems, people with pre-existing health conditions, pregnant women and children. More findings on this virus are needed to draw definitive conclusions regarding the pathogenicity and virulence of the Ebola Reston virus in humans.

The incubation period varies from 2 to 21 days. Patients remain contagious as long as the blood and secretions contain viruses. In a patient with a laboratory-acquired infection, the Ebola virus was isolated from the seminal fluid even on the 61st day after illness.

GLE is a severe acute viral infection, often accompanied by a sudden onset of fever, severe weakness, muscle pain, headache and sore throat. Next are vomiting, diarrhea, rashes, impaired kidney and liver function, and in some cases internal and external bleeding. Laboratory tests reveal leukopenia and thrombocytopenia as well as an increase in liver enzymes.

Before diagnosing GLE, the following diseases should be excluded: malaria, typhoid fever, shigellosis, cholera, leptospirosis, plague, rickettsiosis, relapsing fever, meningitis, hepatitis and other viral hemorrhagic fevers.

The final diagnosis of Ebola virus infections can only be made in the laboratory on the basis of a number of different tests, such as:

Testing samples taken from patients represents an extremely high biological risk and can therefore only be carried out under conditions of maximum biological isolation.

There is still no authorized GLE vaccine. Several vaccines are under study, but no vaccine is available for clinical use. In severe cases, intensive supportive care is required. Patients usually suffer from dehydration and need an intravenous infusion or oral rehydration with solutions containing electrolytes. Etiotropic treatment is absent. New drugs are being evaluated.

Possible natural hosts for the Ebola virus in Africa are fruit bats of the genera Hypsignathus monstrosus, Epomops franqueti and Myonycteris torquata. As a result, the geographic distribution of Ebola viruses may coincide with the range of these fruit-eating bats.

Although primates are a source of infection for humans, they are not viewed as a reservoir, but rather as a random host, like humans. Since 1994, outbreaks of Ebola caused by species from Zaire and the Thai forest have been identified in chimpanzees and gorillas.

The Ebola Reston virus has caused several serious epidemics of VVD in macaques (Macaca fascicularis) kept on farms in the Philippines and in monkeys introduced from the Philippines to the United States in 1989, 1990 and 1996. and in Italy in 1992

Since 2008, Ebola Reston viruses have been detected in a series of deadly disease outbreaks in pigs in China and the Philippines. Asymptomatic infection has been detected in pigs and inoculation for experimental purposes, as a rule, demonstrates that the Ebola Reston virus does not cause disease in pigs.

There is no vaccine against the Ebola Reston virus for animals. Regular cleaning and disinfection of pig and monkey farms (using sodium hypochlorite or other detergents) is considered to effectively inactivate the virus.

If an outbreak is suspected, the area should be immediately quarantined. To reduce the risk of transmitting the infection from animals to humans, it may be necessary to slaughter infected animals and to carefully monitor the burial or incineration of carcasses. Limiting or prohibiting the movement of animals from infected farms to other areas can reduce the spread of the disease.

Since Ebola Reston outbreaks in pigs and monkeys precede human infections, setting up an active animal health surveillance system to identify new cases of disease is essential to provide early warning to veterinary services and public health authorities.

In the absence of effective treatment and vaccines for people, awareness of the risk factors for Ebola infection and personal protective measures is the only way to reduce morbidity and mortality in people.

In Africa, during GLE outbreaks, public health education messages aimed at reducing risks should cover several factors.

Pig farms in Africa can contribute to the spread of infection due to the presence of fruit-eating bats on these farms. Appropriate biosecurity measures must be taken to limit the spread of the virus. For Ebola Reston virus, health education messages should aim to reduce the risk of transmission of infection from swine to humans due to unsafe breeding and slaughter practices, as well as unsafe consumption of blood fresh, raw milk or animal tissue. When handling sick animals or their tissues and when slaughtering animals, gloves and other suitable protective clothing should be worn. In areas where the Ebola Reston virus is detected in pigs, all animal products (blood, meat and milk) must be thoroughly cooked before consumption.

Human-to-human transmission of the Ebola virus occurs mainly through direct or indirect contact with blood and other body fluids. Transmission of infection to health workers is recorded if appropriate infection control measures are not followed.

GLE is difficult to detect in patients because the first symptoms are not specific. For this reason, it is important that healthcare providers constantly take standard precautions when performing duties and caring for patients. These include basic hand and respiratory hygiene, the use of personal protective equipment (depending on the risk of splashes or other means of contact with infected material), the establishment of safe injections and the safe burial of the dead.

Health care providers treating patients with suspected or confirmed Ebola infection should, in addition to standard precautions, take infection control measures to prevent exposure to the patient's blood and body fluids and / or direct contact unprotected with a potentially contaminated environment. In close contact (less than a meter) with a GLE patient, medical personnel should wear face protection (face shield or medical mask and glasses), a clean, non-sterile robe with long sleeves and gloves (for some procedures - sterile).

Laboratory workers are also at risk. Samples taken for diagnosis from humans and animals suspected of having Ebola should be handled by specially trained personnel in properly equipped laboratories.

WHO provides technical knowledge and documentation to support the investigation and control of the disease.

Recommendations for infection control in the care of patients with suspected or confirmed Ebola hemorrhagic fever are contained in “Preliminary recommendations for infection control in the care of patients with suspected or confirmed filovirus (Ebola) hemorrhagic fever , Marburg), March 2008. update of this document.

WHO has developed a standard health warning leaflet (also updated). Standard precautions are designed to reduce the risk of transmission of blood-borne pathogens and other fluids. Precautions, if used universally, can prevent most infections from contact with blood and other body fluids.

Standard precautions are recommended for the care and treatment of all patients, regardless of infection status, suspected or confirmed. They include the basic level of infection control: hand hygiene, use of personal protective equipment to prevent direct contact with blood and body fluids, prevention of needlestick injuries and injuries from other sharp instruments, as well as a number of environmental protection measures.