Crimean hemorrhagic fever

Crimean haemorrhagic fever (hemorrhagic fever Crimea-Congo-Khazer, Central Asian haemorrhagic fever, acute infectious capillarotoxicosis, Crimean-Congolese fever) is an acute viral natural focal infectious disease with a transmissible mechanism of transmission of the pathogen, characterized by fever, general intoxication, severe hemorrhagic syndrome and severe flow. Crimean hemorrhagic fever is considered dangerous infectious diseases.

ICD-10 code

A98.0. Crimean hemorrhagic fever (caused by the Congo virus).

Epidemiology of the Crimean hemorrhagic fever

The main natural reservoir of the causative agent of the Crimean hemorrhagic fever is mites of the genus Hyalomma (H. Plumbeum, H. Scupens, H. Marginatus), Rhipicephalus (Rh. Rossicus), Dermacentor (D. Marginatus and D. Reticulatus) and Boophilus (B. Annulatus ); as well as wild (rabbits, African hedgehogs) and domestic (sheep, goats, cows) animals. Human infection occurs transmissible (through the tick bite), contact (by contact with damaged skin and mucous membranes of blood and bloody discharge of the patient of the Crimean hemorrhagic fever and when crushing the mites) and aerogenic (in the laboratory) ways. Susceptibility to Crimean haemorrhagic fever is high regardless of age, but men aged 20-50 (hunters, shepherds, veterinarians, livestock keepers, field breeders), and milkmaids, medical workers and persons involved in caring for patients are more often sick: laboratory assistants with blood: members of their families.

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What causes Crimean hemorrhagic fever?

Crimean hemorrhagic fever is caused by the arbovirus of the family Bunyaviridae, genus Nairovirus: spherical or ellipsoidal, 90-105 nm in size; covered with a lipid-containing membrane with spines. The genome of the virus contains 3 fragments (L-, M-, S-) of the single-stranded annular "minus" RNA chain encoding transcriptase, nucleocapsid protein (N), and enveloped glycoproteins (G1 and G2). The hemagglutinating ability of the causative agent of the Crimean hemorrhagic fever provides one of the surface glycoproteins. The causative agent of CGL is able to reproduce in brain cells in the abdominal cavity of newborn white mice, in newborn white rats and in the culture of transplanted kidney cells of piglets. After passage through a living organism, the virus increases virulence. The causative agent of the Crimean hemorrhagic fever can be inactivated with disinfectant solutions, fat solvents (ether, paraformaldehyde, alcohol). At 45 C, the virus dies within 2 hours, when boiled - instantly. Well preserved in the frozen state.

Pathogenesis of Crimean hemorrhagic fever

Crimean hemorrhagic fever has been studied insufficiently. After penetration into the human body, the virus multiplies in the vascular endothelium, epithelial cells of the liver, kidneys and in the reticuloendothelial system, causing vasculitis with a predominant lesion of the vessels of the microcirculatory bed. Then viremia develops, which corresponds to the initial period of the disease. According to PCR, viremia lasts 5-9 days. Its intensity correlates with the severity of the course of the disease. As a result of direct vasotropic action of the virus, adrenal and hypothalamus damage, there is an increase in vascular permeability and an increase in disturbances in the hemostatic system, which is clinically expressed by symptoms of hemorrhagic diathesis.

What are the symptoms of Crimean hemorrhagic fever?

Crimean hemorrhagic fever has an incubation period of 2-14 days (on average 3-5).

Crimean hemorrhagic fever without hemorrhagic syndrome can occur in mild and moderate forms; with hemorrhagic syndrome - in mild, moderate and severe forms. The course of the disease is cyclical and includes the following periods:

• the initial period (prehemorrhagic);
• the period of heat (hemorrhagic manifestations);
• period of convalescence and long-term consequences (residual).

How is the Crimean hemorrhagic fever diagnosed?

Clinical diagnosis of Crimean hemorrhagic fever is based on the symptoms of the disease:

• Crimean hemorrhagic fever has an acute onset with high fever, hyperemia of the face and visible mucous membranes, spontaneous muscular and joint pains, intense headache, nausea, vomiting, bleeding gums, hemorrhagic enanthem on the mucous membranes, petechial rash with typical localization; hepatomegaly; bradycardia; hypotension; nasal, pulmonary, gastrointestinal, uterine bleeding: a two-wave temperature curve.
• The presence of bite marks on the body.
• Epidemiological anamnesis (stay in endemic for the Crimean hemorrhagic fever region, contact with a sick Crimean hemorrhagic fever).
• Seasonality.

How is the Crimean hemorrhagic fever treated?

Crimean hemorrhagic fever is treated with specific, pathogenetic and symptomatic methods. It is necessary to avoid unreasonable prescribing of medical manipulations, accompanied by traumatization of cutaneous and mucous membranes. Treatment of Crimean hemorrhagic fever should be carried out under daily control of the coagulogram and the number of platelets (2 times per day).

What is the prognosis of the Crimean hemorrhagic fever?

Crimean hemorrhagic fever has a different prognosis, which depends on adherence to the principles of hospitalization, patient care, timely and comprehensive medication, prevention of complications. Late hospitalization and diagnosis, late treatment of Crimean hemorrhagic fever, incorrect or contraindicated transportation of patients during the period of severe bleeding can lead to death.