Marburg virus disease is an acute infectious disease caused by an RNA–containing filovirus (Marburg virus), occurring with severe capillarotoxicosis and high mortality. Symptoms include high fever, severe intoxication, severe diarrhea and vomiting, skin hemorrhages, internal bleeding, liver, heart, kidney, and central nervous system damage. The diagnosis takes into account epidemiological and clinical data, the results of laboratory (virological, serological, electron microscopic) studies. Patients with Marburg virus disease are subject to hospitalization and isolation; treatment is mainly symptomatic; sometimes interferon therapy, the introduction of plasma convalescents are effective.
General information
Marburg virus disease is a natural focal infection characterized by severe intoxication and hemorrhagic syndrome, damage to the liver, gastrointestinal tract, central nervous system and other internal organs. Marburg virus disease belongs to a group of particularly dangerous (quarantine) infections characterized by high contagiousness and lethality. The first outbreak of the disease was registered in 1967 in the cities of Marburg and Frankfurt, which is why the infection was called “Marburg virus disease”, “Marburg disease”; also synonyms of this pathology are “Maridi hemorrhagic fever”, “green monkey disease”, etc. In addition to Germany, cases of Marburg virus diseaser were observed in Serbia, Sudan, South Africa, and Kenya.
Causes
The causative agent of Marburg virus disease (Marburgvirus) belongs to the family of filoviruses. Virions have a spiral, worm-like or rounded shape; length 665-1200 nm and diameter 70-80 nm; contain RNA and lipoprotein. The resistance of the virus in the external environment is average. In its morphology and properties, the Marburg virus is similar to the viruses that cause Ebola, but there are some differences in the antigenic structure between them.
The source of the European outbreak of Marburg virus disease in 1967 was green monkeys imported from Africa, most of which died from an unknown disease. Hemorrhagic fever then developed in people who came into contact with primates, as well as in medical personnel caring for patients. In total, out of 25 patients with Marburg virus disease, 7 people died. Later, similar cases of the disease were recorded in the natural habitats of African green monkeys, which gave reason to consider them as the main source of infection and reservoir of the Marburg virus.
Infection of a person is possible by contact with the patient’s blood and other secretions; by airborne droplets when the virus enters the mucous membranes of the oral cavity and conjunctiva; by injection with injections. There is a known case of infection with Marburg virus disease sexually. After an infection, a long-term immunity is formed; cases of recurrent disease are not known. After penetration and primary replication of the virus in the cells of the monocyte-macrophage system, massive viremia develops, suppressing immune responses. This leads to generalized microcirculation disorders and the development of DIC syndrome, capillarotoxicosis and multiple organ lesions. Foci of hemorrhages and necrosis in Marburg virus disease are formed in the myocardium, lungs, liver, kidneys, adrenal glands, spleen and other organs.
Symptoms
From the moment of infection to the appearance of the first symptoms, it takes from 2 days to 3 weeks. The manifestation of the disease is acute, without prodromal phenomena. Characteristic signs of Marburg virus disease are prolonged (for 2 weeks) and high fever (up to 39-40 ° C), chills, severe intoxication, accompanied by headache, bruising, myalgia and arthralgia. From the first day, the patient has an enanthema, conjunctivitis, erosion on the oral mucosa. On 3-4 days, the course of Marburg virus disease is burdened with cramping abdominal pain, vomiting, watery diarrhea, resulting in rapid dehydration of the body.
On the 5th-6th day of the disease, a maculopapular rash appears on the trunk, upper limbs, neck and face, often accompanied by itching and peeling of the skin. In the future, hemorrhagic syndrome develops: hemorrhages in the skin and conjunctiva; gingival, nasal, uterine, gastrointestinal bleeding. By the end of the first week, patients with Marburg virus disease have signs of hepatitis, myocarditis, and kidney damage. Changes on the part of the central nervous system are characterized by adynamia, inhibition, convulsions, loss of consciousness.
The signs of toxicosis, dehydration, hemorrhagic manifestations and multiple organ disorders reach their maximum severity in the second week of the disease. The death of patients with Marburg virus disease can occur from edema of the lungs or brain, hypovolemic shock, DIC syndrome, acute renal failure. In surviving patients, the period of convalescence has a protracted character: asthenization persists for a long time, headaches and muscle pains, periodic abdominalgia; alopecia often develops. Complications and residual effects include uveitis, encephalitis, myelitis, orchitis, testicular atrophy, pneumonia, mental and intellectual disorders.
Diagnostics
Diagnosis is based on clinical, epidemiological and laboratory data. When collecting anamnesis, the fact of the patient’s stay in a natural focal area, contact with disease vectors and sick people is revealed. Nonspecific changes in blood include leukopenia, thrombocytopenia, increased levels of liver enzymes. In order to confirm the diagnosis of Marburg virus disease, molecular biological and serological (RT-PCR, RIF, ELISA), electron microscopic studies are used. Biomaterial testing is carried out in special laboratories in compliance with the requirements of maximum safety.
To assess the damage to internal organs, an ECG, ultrasound of the kidneys and ultrasound of the liver, a study of the coagulogram, and urinalysis are performed. Due to the development of multiple organ disorders, patients need to consult a nephrologist, neurologist, gastroenterologist, cardiologist, hematologist, ophthalmologist.
Differential diagnosis is carried out with other hemorrhagic fevers (yellow, hemorrhagic with renal syndrome, Crimean, Omsk, Bolivian, Argentine hemorrhagic, Lasa fever, Ebola fever, etc.). Malaria, cholera, shigellosis, typhoid and recurrent typhoid, leptospirosis, hepatitis, meningitis, etc. are also excluded.
Treatment
Patients should be immediately hospitalized in an infectious hospital and isolated in separate boxes. When organizing patient care, measures of increased sanitary and epidemiological control are being taken: disinfection measures are being strengthened, protection of medical personnel is being organized, safe medical and diagnostic manipulations and procedures are being organized.
Etiotropic therapy of has not been developed, therefore, the main attention is paid to pathogenetic and symptomatic measures. Parenteral detoxification therapy and oral rehydration, intravenous administration of platelet mass are carried out. There is information about the effectiveness of the introduction of plasma convalescents, interferon therapy, plasmapheresis. With the development of bacterial complications, antibiotic therapy is prescribed.
Prognosis and prevention
The disease has a serious prognosis and poses an increased risk in terms of the occurrence of epidemic outbreaks. Mortality among patients with Marburg virus disease is 25-70%. When detecting cases of Marburg virus disease, strict observance of the precautions recommended when working with particularly dangerous infections is necessary. Transportation and treatment of patients is carried out in special isolation wards. Patients should be cared for by specially trained personnel using personal protective equipment. Specific prevention has not been developed. It is advisable to organize epidemic control over people coming from endemic regions.
