Crimean Congo hemorrhagic fever

The causative agent of the disease is a virus from the genus Orthonairovirus of the order Bunyavirales . Refers to arboviruses . It was discovered in 1945 by M.P. Chumakov in the Crimea , while examining the blood of sick soldiers and immigrants who became ill during hay harvesting.

The natural reservoir of the pathogen - rodents , cattle and small cattle , birds, wild species of mammals, also ticks themselves, capable of transmitting the virus to offspring through eggs, and which are virus carriers for life. The source of the pathogen is a sick person or an infected animal. The virus is transmitted by a tick bite or medical procedures related to injections or blood sampling. The main carriers are ticks Hyalomma marginatus , Dermacentor marginatus , Ixodes ricinus . In 2012, 74 cases of the disease were recorded on the territory of Russia : 41 in the Rostov Region , 24 in the Stavropol Territory , 6 in the Astrakhan Region , 3 in Kalmykia and the Crimea ^[4] . Also, diseases were noted in Central Asia , China , Bulgaria , in the territory of the former Yugoslavia , in Pakistan , Central, East and South Africa ( Congo , Kenya , Uganda , Nigeria , etc.). In 80% of cases, people aged 20 to 60 years fall ill.

Not fully understood. The gates of infection are the skin at the site of a tick bite or minor skin lesions that come into contact with the blood of patients during nosocomial manipulations (for example, when blood is taken for analysis performed without proper precautions). With a tick bite, local changes are not pronounced. The virus enters the bloodstream and accumulates in the cells of the reticuloendothelial system .

In the second stage of the disease, after virus replication and the massive release of new viruses from cells into the bloodstream, general severe intoxication of the body is observed, vascular endothelium is affected, their permeability increases, hemorrhagic diathesis develops (hemorrhages on the skin and mucous membranes, in internal organs).

The incubation period is from one to 14 days. More often 2-9 days. The prodromal period is absent. The disease develops acutely. At the first stage, sharply, in a short time, the temperature rises to 39-40 degrees Celsius and above, headache begins, chills, sometimes very severe, redness of the face, mucous membranes. There are signs of general intoxication of the body (severe weakness, pain in the muscles, joints, nausea, vomiting). After 2-4 days, the second, hemorrhagic stage of the disease begins. The patient's condition worsens sharply. Hemorrhages appear on the skin and mucous membranes in the form of a rash, spots, hematomas. There is increased bleeding of the gums , injection sites. Possible nasal, uterine bleeding . Pain begins in the abdomen, liver, diarrhea, vomiting, possibly jaundice, oliguria. The disease lasts 10-12 days, but patients remain severely malnourished for another 1-2 months. Sometimes the second stage is less pronounced, and the disease remains undetected, since the initial symptoms are similar to those in acute respiratory infections. As complications, sepsis, pulmonary edema, focal pneumonia, acute renal failure, otitis media, thrombophlebitis can be observed. Mortality is from 2 to 50%.

An autopsy reveals multiple hemorrhages in the mucous membranes of the gastrointestinal tract, blood in its lumen, but there are no inflammatory changes. The brain and its membranes are hyperemic, hemorrhages with a diameter of 1-1.5 cm are found in them with the destruction of the brain substance. Minor hemorrhages are detected throughout the brain. Hemorrhages are also observed in the lungs, kidneys, and liver.

Patients must be isolated in the infectious ward of the hospital. The treatment is symptomatic and etiotropic. Prescribe anti-inflammatory drugs, diuretics. Exclude the use of drugs that enhance kidney damage, for example, sulfonamides. Antiviral drugs (ribavirin) are also prescribed. In the first 3 days, a heterogeneous specific equine immunoglobulin, immune serum, plasma or specific immunoglobulin obtained from the blood serum of ill or vaccinated individuals is administered. Specific immunoglobulin is used for emergency prophylaxis in persons in contact with the patient’s blood.

The natural susceptibility to the virus in humans is high. After recovery, immunity remains, which lasts 1-2 years. To create artificial immunity, formol vaccine is used from the brain of infected suckers of white mice or white rats.

To prevent infection, the main efforts are directed at combating the vector of the disease. They carry out pest control of livestock buildings and prevent grazing on pastures located on the territory of the natural outbreak. Individual protective clothing should be worn individually. Handle clothes, sleeping bags and tents with repellents. In case of tick bites in the habitat zone, immediately contact a medical institution for help. For people who are planning to enter the territory of the South of Russia, preventive vaccination is recommended. In medical institutions, one should take into account the high contagiousness of the virus, as well as its high concentration in the blood of patients. Therefore, patients should be placed in a separate box, and trust service only to specially trained personnel.

• Hemorrhagic fever
• Omsk hemorrhagic fever

• Tovpinets N. N., Evstafiev I. L. Natural focality of zoonotic infections in Crimea: epizootological and epidemiological aspects
• Chumakov M.P. , Loban K.M. Crimean hemorrhagic fever // Big Medical Encyclopedia , 3rd ed. - M .: Soviet Encyclopedia. - T. 12.

• http://humbio.ru/humbio/infect_har/00123b34.htm
• Crimean Congo hemorrhagic fever
• Attention, the tick "Crimea-Congo." The chief state sanitary doctor of the Russian Federation, corresponding member of the Russian Academy of Medical Sciences Gennady ONISHCHENKO is responsible.