Hemorrhagic fever with renal syndrome in children

Hemorrhagic fever with renal syndrome (HFRS) (hemorrhagic nephrosonephritis, Tula, Ural, Yaroslavl fever) is an acute infectious disease of viral origin, characterized by fever, intoxication, hemorrhagic and renal syndromes.

Epidemiology

Hemorrhagic fever with renal syndrome is a typical zoonotic infection. Natural foci of the disease are in the Far East, Transbaikalia, Eastern Siberia, Kazakhstan and the European part of the country. The reservoir of infection are mouse-like rodents: field and forest mice, rats, voles, etc. The infection is transmitted by gamasid ticks and fleas. Mouse-like rodents carry the infection in a latent, less often in a clinically expressed form, while they release the virus into the environment with urine and feces. Routes of infection transmission:

• aspiration route - when inhaling dust containing infected excrements of rodents;
• contact route - when infected material comes into contact with scratches, cuts, scarifications, or when rubbed into intact skin;
• alimentary route - when consuming food products infected with rodent excrement (bread, vegetables, fruits, etc.).

Direct human-to-human transmission is unlikely. Hemorrhagic fever with renal syndrome occurs sporadically, but local epidemic outbreaks are possible.

Children, especially those under 7, rarely get sick due to limited contact with nature. The greatest number of diseases is recorded from May to November, which coincides with the migration of rodents into residential and utility rooms, as well as with the expansion of human contact with nature and agricultural work.

Prevention of hemorrhagic fever with renal syndrome

Prevention is aimed at the destruction of mouse-like rodents in the territory of natural foci, prevention of contamination of food products and water sources with rodent excrement, strict observance of sanitary and anti-epidemic regulations in residential premises and around them.

Classification

Along with typical ones, there are latent and subclinical variants of the disease. Depending on the severity of the hemorrhagic syndrome, intoxication and renal dysfunction, mild, moderate and severe forms are distinguished.

Causes of hemorrhagic fever with renal syndrome

The pathogen belongs to the Bunyaviridae family, includes two specific viral agents (Hantaan and Piumale), which can be passaged and accumulated in the lungs of a field mouse. The viruses contain RNA and have a diameter of 80-120 nm, are unstable: at a temperature of 50 °C they survive for 10-20 minutes.

Pathogenesis of hemorrhagic fever with renal syndrome

The infection is primarily localized in the vascular endothelium and, possibly, in the epithelial cells of some organs. After intracellular accumulation of the virus, the viremia phase occurs, which coincides with the onset of the disease and the appearance of general toxic symptoms. The hemorrhagic fever with renal syndrome virus is characterized by capillary toxic action. In this case, damage to the vascular wall occurs, blood clotting is impaired, which leads to the development of thrombohemorrhagic syndrome with the occurrence of multiple thrombi in various organs, especially in the kidneys.

Symptoms of hemorrhagic fever with renal syndrome

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

• Feverish period. The disease usually begins acutely 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 disease, a severe headache is characteristic, mainly in the frontal and temporal regions, dizziness, chills, a feeling of heat, pain in the muscles of the limbs, in the knee joints, aches throughout the body, pain when moving the eyeballs, severe pain in the abdomen, especially in the projection of the kidneys are also possible.
• The oliguric period in children begins early. Already on the 3rd-4th, less often on the 6th-8th day of the disease, the body temperature decreases and diuresis drops sharply, back pain increases. The condition of children worsens even more as a result of increasing symptoms of intoxication and kidney damage. Urine examination reveals proteinuria, hematuria, cylindruria. Renal epithelium, often mucus and fibrin clots are constantly detected. Glomerular filtration and tubular reabsorption are always reduced, which leads to oliguria, hyposthenuria, hyperazotemia, metabolic acidosis. The relative density of urine decreases. With increasing azotemia, a clinical picture of acute renal failure occurs up to the development of uremic coma and eclampsia.
• The polyuric period begins on the 8th-12th day of the disease and marks the beginning of recovery. The condition of patients improves, back pain gradually subsides, vomiting stops, sleep and appetite are restored. Diuresis increases, the daily amount of urine can reach 3-5 liters. The relative density of urine decreases even more (persistent hypoisosthenuria).
• The convalescent period lasts up to 3-6 months. Recovery is slow. General weakness persists for a long time, diuresis and relative density of urine are gradually restored. The state of post-infectious 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 in the leukocyte formula to the left to band and young forms, up to promyelocytes, myelocytes, metamyelocytes. Aneosinophilia, a decrease in the platelet count and the appearance of plasma cells can be detected. ESR is often normal or elevated. In acute renal failure, the level of residual nitrogen in the blood increases sharply, the content of chlorides and sodium decreases, but the amount of potassium increases.

Diagnosis of hemorrhagic fever with renal syndrome

Hemorrhagic fever with renal syndrome is diagnosed based on the characteristic clinical picture: fever, hyperemia of the face and neck, hemorrhagic rashes on the shoulder girdle similar to a whiplash, kidney damage, leukocytosis with a shift to the left and the appearance of plasma cells. The patient's stay in an endemic zone, rodents in the home, consumption of vegetables and fruits with traces of gnawing are important for diagnosis. Specific laboratory diagnostic methods include ELISA, RIF, hemolysis reaction of chicken erythrocytes, etc.

Differential diagnostics

Hemorrhagic fever with renal syndrome is differentiated from hemorrhagic fevers of other etiologies, leptospirosis, influenza, typhus, acute nephritis, capillary toxicosis, sepsis and other diseases.

Treatment of hemorrhagic fever with renal syndrome

Treatment is carried out in a hospital. Bed rest, a full diet with a restriction of meat dishes, but without reducing the amount of table salt are prescribed. At the height of intoxication, intravenous infusions of hemodez, 10% glucose solution, Ringer's solution, albumin, 5% ascorbic acid solution are indicated. In severe cases, glucocorticoids are prescribed at the rate of 2-3 mg / kg per day of prednisolone in 4 doses, the course is 5-7 days. In the oliguric period, mannitol, polyglucin are administered, the stomach is washed with a 2% solution of sodium bicarbonate. With increasing azotemia and anuria, extracorporeal hemodialysis is used using an "artificial kidney" machine. In case of massive bleeding, transfusions of blood products and blood substitutes are prescribed. Sodium heparin is administered to prevent thrombohemorrhagic syndrome. If there is a risk of bacterial complications, antibiotics are used.

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