Hemorrhagic fever with kidney syndrome in children

Hemorrhagic fever with renal syndrome (HFRS) (hemorrhagic nephrozonephritis, Tula, Urals, Yaroslavl fever) is an acute infectious disease of the viral nature, characterized by fever, intoxication, hemorrhagic and renal syndromes.

Epidemiology

Hemorrhagic fever with kidney syndrome is a typical zoonotic infection. Natural foci of the disease are found in the Far East, Transbaikalia, Eastern Siberia, Kazakhstan and the European part of the country. The reservoir of infection is a mouse-like rodent: field and forest mice, rats, voles, etc. The infection is transmitted by gamasid mites and fleas. Mouse rodents carry the infection in latent, less often in a clinically pronounced form, while they excrete the virus in the external environment with urine and feces. Transmission routes:

• aspirating path - by inhalation of dust with suspended infected rodent secretions;
• contact path - if the infected material hits scratches, cuts, scarifications or when rubbed into intact skin;
• alimentary pathway - with the use of food products contaminated with rodent secretions (bread, vegetables, fruits, etc.).

Direct transmission of infection from humans to humans is unlikely. Hemorrhagic fever with renal syndrome is observed in the form of sporadic cases, but local epidemic outbreaks are possible.

Children, especially younger than 7 years old, are ill rarely because of limited contact with nature. The greatest number of diseases is recorded from May to November, which coincides with the migration of rodents to residential and business premises, as well as the expansion of human contacts with nature and the conduct of agricultural work.

Prevention of hemorrhagic fever with renal syndrome

Prevention is aimed at the destruction of rodent mice on the territory of natural foci, prevention of contamination of food and water sources by rodent excrement, strict adherence to the sanitary and anti-epidemic regime in and around living quarters.

Classification

Along with the typical there are erased and subclinical variants of the disease. Depending on the severity of hemorrhagic syndrome, intoxication and violations of the kidneys distinguish between light, medium and heavy forms.

Causes of hemorrhagic fever with renal syndrome

The causative agent belongs to the family Bunyaviridae, includes two specific virus agents (Hantaan and Piumale), which can passivate and accumulate in the lung of the field mouse. The viruses contain RNA and have a diameter of 80-120 nm, low stability: at a temperature of 50 ° C, 10-20 minutes remain.

Pathogenesis of hemorrhagic fever with renal syndrome

Infection is primarily localized in the vascular endothelium and, possibly, in the epithelial cells of certain organs. After intracellular accumulation of the virus, the phase of viremia begins, which coincides with the onset of the disease and the appearance of general toxic symptoms. The virus of hemorrhagic fever with renal syndrome is characterized by a capillarotoxic effect. In this case, the vascular wall is damaged, blood coagulability is violated, which leads to the development of thrombohemorrhagic syndrome with the appearance of multiple blood clots in various organs, especially in the kidneys.

Symptoms of hemorrhagic fever with kidney syndrome

The incubation period is from 10 to 45 days, an average of about 20 days. There are four stages of the disease: febrile, oliguric, polyuric and convalescent.

• Feverish period. The disease begins, as a rule, acute with a rise in temperature to 39-41 ° C and the appearance of general toxic symptoms: nausea, vomiting, lethargy, inhibition, sleep disorders, anorexia. From the first day of the illness, a severe headache is characteristic, mainly in the frontal and temporal regions, dizziness, cognition, heat, pain in the muscles of the limbs, in the knee joints, aches in the whole body, soreness in the movement of the eyeballs, severe abdominal pain, especially in the projection of the kidneys.
• The oliguric period in children comes early. Already on the 3-4th, less often on the 6-8th day of the disease, the body temperature decreases and diuresis drops sharply, pains in the lower back increase. The state of children worsens even more as a result of an increase in the symptoms of intoxication and kidney damage. In the study of urine, proteinuria, hematuria, and cylindruria are identified. Constantly detect the kidney epithelium, often mucus and clots of fibrin. Glomerular filtration and tubular reabsorption are always lowered, which leads to oliguria, hypostenuria, hyperazotemia, metabolic acidosis. The relative density of urine decreases. With the growth of azotemia there is a clinical picture of acute renal failure, up to the development of uremic coma and eclampsia.
• The polyuric period begins with the 8-12th day of the disease and marks the beginning of recovery. The condition of the patients improves, the pain in the lower back gradually stops, vomiting stops, sleep and appetite are restored. Diuresis is increasing, the daily amount of urine can reach 3-5 liters. Relative density of urine decreases even more (persistent hypoisostenuria).
• The convalescence period lasts up to 3-6 months. Recovery comes slowly. The general weakness remains for a long time, diuresis and relative density of urine are gradually restored. The condition of postinfectious asthenia can persist for 6-12 months. In the blood in the initial (febrile) period, short-term leukopenia is noted, quickly replaced by leukocytosis with a shift of the leukocyte formula to the left until the stab and nuclear forms, including promyelocytes, myelocytes, metamyelocytes. You can detect aneosinophilia, a drop in platelet count and the appearance of plasma cells. ESR is often normal or increased. In acute renal failure, the level of residual nitrogen in blood sharply increases, the content of chlorides and sodium sharply decreases, but the amount of potassium increases.

Diagnosis of hemorrhagic fever with renal syndrome

Hemorrhagic fever with kidney syndrome is diagnosed on the basis of a characteristic clinical picture: fever, face and neck hyperemia, hemorrhagic eruptions on the shoulder belt as a type of trauma from a lash, kidney damage, leukocytosis with a left shift and the appearance of plasma cells. For the diagnosis, the stay of the patient in the endemic zone, the rodents in the dwelling, the consumption of vegetables, fruits with traces of pogrings are important. Specific methods of laboratory diagnosis include ELISA, RIF, hemolysis reaction of chicken red blood cells, etc.

Differential diagnostics

Hemorrhagic fever with renal syndrome is differentiated with hemorrhagic fevers of other etiology, leptospirosis, influenza, typhus, acute nephritis, capillarotoxicosis, sepsis and other diseases.

Treatment of hemorrhagic fever with renal syndrome

The treatment is carried out in a hospital. Assign bed rest, a full-fledged diet with the restriction of meat dishes, but without reducing the amount of table salt. At the height of intoxication, intravenous haemodesis infusions, 10% glucose solution, Ringer's solution, albumin, 5% ascorbic acid solution are shown. In severe cases, appoint glucocorticoids from the calculation of 2-3 mg / kg per day of prednisolone in 4 sessions, the course is 5-7 days. In the oliguric period, mannitol, polyglukin is injected, the stomach is washed with a 2% sodium bicarbonate solution. With increasing azotemia and anuria, extracorporeal hemodialysis is used with the aid of the "artificial kidney" apparatus. With massive bleeding appoint transfusions of blood products and blood substitutes. To prevent thrombohemorrhagic syndrome, heparin sodium is administered. At a threat of bacterial complications, antibiotics are used.

[1], [2], [3], [4], [5], [6], [7]