Omsk hemorrhagic fever in children

Omsk hemorrhagic fever (OHF) is an acute infectious disease of viral origin with a transmissible route of transmission, accompanied by fever, hemorrhagic diathesis, transient damage to the kidneys, central nervous system and lungs.

ICD-10 code

A98.1 Omsk hemorrhagic fever.

Epidemiology of Omsk hemorrhagic fever in children

The main reservoirs of the infection are the muskrat and the water vole, as well as some species of small mammals and birds. The virus persists in ticks for a long time and is transmitted to offspring transovarially. Humans become infected through the bites of the ixodid tick Dermacentor pictus. Humans can also become infected through water, food, aspiration, and contact. The greatest number of cases are recorded in the spring and summer months. The infection is not transmitted from person to person.

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What causes Omsk hemorrhagic fever in children?

The causative agent of the disease is a virus from the genus Flavivirus, family Togaviridae. Contains RNA, the diameter of the virion is 30-40 nm, pathogenic for many wild and laboratory animals (muskrats, white mice, rabbits, guinea pigs, etc.). The Omsk hemorrhagic fever virus is found in the blood of patients in the acute period of the disease and in the body of Dermacentorpictu ticks - the main carriers of the disease.

Pathogenesis of Omsk hemorrhagic fever in children

The main pathogenetic link is the virus's damage to the vessel wall, which causes hemorrhagic syndrome and focal hemorrhages in the internal organs. Of great importance is the virus's damage to the central and autonomic nervous system, as well as the adrenal glands and hematopoietic organs. After the disease, persistent immunity remains.

Symptoms of Omsk hemorrhagic fever in children

Omsk hemorrhagic fever in children has an incubation period of about 2-5 days, rarely extending to 10 days, after which typical symptoms of Omsk hemorrhagic fever appear. The disease begins acutely with a rise in body temperature to 39-40 ° C, headache, chills, body aches, nausea, dizziness, pain in the calf muscles. The patient's face is hyperemic, slightly puffy, the sclera vessels are injected, the lips are dry, bright, sometimes covered with bloody crusts. Hyperemia of the soft and hard palate with spotted enanthem and hemorrhagic punctate hemorrhages are constantly detected. Bleeding gums are often noted. From the 1st to 2nd day of the disease, roseolous and petechial rash appears on the anterior and lateral surfaces of the chest, on the extensor surfaces of the arms and legs. In severe cases, extensive hemorrhages may occur in the abdomen, sacrum, and shins. In the following days, extensive necrosis may appear in these areas. Nasal, pulmonary, uterine, and gastrointestinal bleeding are also possible. Hemorrhagic symptoms usually appear in the first 2-3 days of the disease, but may also occur later - on the 7th-10th day.

The kidneys are constantly affected. Albuminuria appears first, then short-term hematuria and cylindruria join. Vacuolated granular cells of the renal epithelium are found in the urine sediment. Diuresis is significantly reduced. From the first day of the disease, leukopenia, moderate neutrophilia with a shift to the left, thrombocytopenia are found in the blood; ESR is normal or reduced.

Diagnosis of Omsk hemorrhagic fever in children

Omsk hemorrhagic fever is diagnosed based on fever, pronounced hemorrhagic diathesis in combination with catarrhal phenomena, facial hyperemia and injection of scleral vessels, persistent hypotension and bradycardia. Diagnosis of Omsk hemorrhagic fever is facilitated by characteristic changes in the urinary sediment and blood. Staying in a natural focus of infection should also be taken into account. Specific methods include virus isolation and detection of an increase in the titer of specific antibodies in the RSK, RTGA, diffuse precipitation reaction in agar gel or RN in the dynamics of the disease.

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Differential diagnostics

Omsk hemorrhagic fever is differentiated from leptospirosis, tick-borne viral encephalitis, influenza, capillary toxicosis, mosquito fever, HFRS and other hemorrhagic fevers.

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Treatment of Omsk hemorrhagic fever in children

Treatment of Omsk hemorrhagic fever is exclusively pathogenetic, aimed at combating intoxication (intravenous administration of 5-10% glucose solution, 1.5% reamberin solution, rheopolyglucin, etc.) and hemorrhagic manifestations (vitamin K, vikasol, blood transfusions, etc.). In severe cases, glucocorticoids and cardiac agents are indicated; antibiotics are prescribed for bacterial complications.

How to prevent Omsk hemorrhagic fever in children?

It is aimed at improving the health of natural foci and preventing infection of children in summer camps and kindergartens located in the natural foci zone. For active immunization, a killed vaccine from the brain of white mice infected with the Omsk hemorrhagic fever virus is proposed. Vaccination is carried out according to strict epidemiological indications.