Hemorrhagic fever with renal syndrome: causative agent, symptoms, diagnosis, treatment

Hemorrhagic fever is a disease whose history began in 1935 in the Far East. Later and to this day outbreaks of the disease in Russia began to be noted in the regions both in the Central region of the country and in the Urals.

Hemorrhagic fever with renal syndrome

Hemorrhagic fever with renal syndrome( HFRS) is an acute viral disease carried by small rodents, which is characterized by vascular lesions and negatively affecting primarily kidney function.

Any person is susceptible to Hantavirus, that is, getting into the blood Puumala becomes the catalyst of the pathological process in all people who did not have hemorrhagic fever earlier. But, according to statistics, the vast majority of people who have encountered HFRS - men aged 18 to 50 years.

There are two types of HFRS, divided according to the source of infection:

• type I( eastern) is distributed by the field mouse, the clinical picture is severe, the death rate as a result of therapy is 20%;
• type II( western) is distributed by red-breasted voles, symptomatology of the disease is easier than in type I, mortality rate is less than 2% against treatment.
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Etiology

There are six ways of infection, but they are all united by human contact with a virus that enters the environment from saliva and stool feces:

1. The forest type occurs most often, with it a person becomes infected duringhiking in the forest, searching for mushrooms, picking berries.
2. A household type means that the source of Hantavirus is inside a person's house - this is found in private houses located near the forest.
3. Production type - occurs when drilling, oil pipeline and other work in the forest.
4. Garden-garden type - is relevant among summer residents.
5. The camp type of infection is recorded among children and adolescents who are resting in summer suburban camps.
6. The agricultural way is marked by activity in autumn and winter.

In an overwhelming number of cases, the virus penetrates the body by getting on the mucosa of the upper respiratory tract, less often - through damage to the skin.
On the video, the etiology of hemorrhagic fever:

Pathogenesis

After entering the body, the virus begins to hit the walls of the vessels from the inside, destroying the inner layer - the endothelium. The vessels become permeable, the plasma leaves the vascular system through the perforation, and the blood condenses.

Vascular damage negatively affects the activity of absolutely all systems, but most of all with HFRS kidneys suffer: as the stages of this disease progress, the glomerular filtration rate( GFR) decreases, the risk of chronic renal failure increases, in the terminal stage requiring hemodialysis.

Clinical picture

Incubation period

The incubation period of HFRS lasts from 1 to 7 weeks, more often - 3 weeks. At this stage, the patient does not feel the symptoms of the disease, but the pathology in the body already takes place: the walls of the vessels are affected, the composition of the blood changes, and the functioning of all systems begins.

Prodromal manifestations

The prodromal period does not always occur and lasts no more than 3 days.

It occurs after the expiration of the incubation period of HFRS and has the following symptoms:

• weakness;
• headache;
• chills;
• aches in the bones;
• a subfebrile condition.

The

fever for hemorrhagic fever with renal syndrome is characterized by a sharp onset of fever, with fever rising to 39-40 degrees. It lasts from 2 to 8 days, the peak of thermometer indicators is not for evening and night hours, as with influenza or ARVI, but in the morning.

Hemorrhagic period

The hemorrhagic period begins with the appearance of the rash on the skin and the hemorrhage of the sclera of the eyes. This stage proceeds simultaneously with the oligurical stage.

With hemorrhagic syndrome the following phenomena occur:

• "red cherry" syndrome - hemorrhages on the eye proteins;
• infectious-toxic shock - the reaction of the body when there is a virus in it, expressed in a decrease in blood pressure and the pathological work of several systems at once;
• internal bleeding.

Oliguria

Oliguria develops from the third day after the onset of HFRS symptoms and, statistically, can last up to 1 month, but usually takes 9-12 days.

Oliguria - a decrease in the quantitative index of excreted urine in the usual drinking regime. In this period there are active changes in blood: substances previously excreted by the urinary system remain in the blood, poisoning the body.

The pathological processes in systems:

• cardiovascular( hypotension, bradycardia, extrasystole) are fixed at once.
• digestive( nausea, vomiting, sometimes with blood);
• nervous( delirium, hallucinations, syncope).

Polyuria

Polyuria begins after the oliguric period, that is, after 9-12 days from the onset of HFRS, and lasts up to 4 weeks.

During this period, the amount of urine, on the contrary, increases sharply, and diuresis can reach 10 liters. Because of the large amount of urine, its density is reduced, and protein and cylinders are also found in it.

Reconvalence period

After the completion of polyuria, a person's recovery comes. But abnormalities in laboratory analyzes can last up to three years.

During the recovery of the body, a person can experience fatigue, face functional disorders of the nervous and endocrine system, in the kidneys.

On the video, symptoms and pathogenesis of hemorrhagic fever:

Diagnosis

Differential diagnosis for hemorrhagic fever with nephrologic syndrome is required to exclude pathologies:

• influenza;
• typhoid fever;
• leptospirosis;
• glomerulonephritis;
• tick-borne rickettsiosis;
• encephalitis;
• pyelonephritis.

For diagnosis, the main instrument can be called patient observation, questioning and examination, which fix:

• strict alternation of the described stages in this order;
• the fact of decreasing the amount of released urine after temperature stabilization;
• presence of traces of hemorrhages on the skin.

The second factor that confirms HFRS is epidemiological data on the possibility of HFRS infection in the area.

Laboratory tests are performed to confirm the diagnosis:

• general urine analysis for the detection of proteinuria( presence of protein traces in urine), cylinduria;
• a general blood test to detect leukocyte elevation, erythrocyte sedimentation rate, plasma cells;
• biochemical blood test for detecting increased levels of creatinine and urea, lowering albumin;
• Reberg's test, which determines GFR;
• detection of IgM type antibodies.

At the stage of nephrologic symptoms, renal ultrasound and contrast radiography are prescribed.

Treatment of

Therapy of HFRS is performed in a hospital setting, with strict bed rest and therapeutic nutrition, which reduces the burden on the kidneys. The amount of urine consumed and released per day is monitored.

Drug therapy is used primarily for relief of symptoms:

• for intravenous injection is administered intravenous glucose( 20-40%) and saline;
• for the restoration of kidney function and improve the microcirculation of glomeruli are used preparations "Kurantil", "Trental", "Eufillin", in case of severe disease, hormonal preparations( glucocorticosteroids) - "Prednisolone", "Metipred";
• with strong internal hemorrhages, blood and albumin transfusion is performed;
• during the oliguria uses the hemodialysis apparatus to normalize blood composition and remove excess fluid from the body;
• to reduce body temperature used antipyretic: "Paracetomol", "Nize".

Complications and complications

1. Infectious-toxic shock and azotemic uremia - poisoning the body with decomposition products during the reduction of GFR of the kidneys or the cessation of urinary output, resulting in multiple organ failure and then uremic coma.
2. Rupture of the capsule of the kidney that occurs against the background of vascular damage and a high load on the cardiovascular system due to accumulating fluid during oliguria.
3. Swelling of the lungs and the brain - this also happens in oliguria, when a large amount of fluid remains in the body, not excreted by inactive kidneys.
4. Lethal outcome - on average, is fixed in 8 percent of cases and depends on the fact of the presence of concomitant somatic pathologies, age, the moment of the onset of adequate therapy.
5. Infectious processes( pyelonephritis, sepsis) belong to the nonspecific category of complications, since for their development it is necessary to penetrate into the body of bacteria that are the catalysts of the described pathologies during HFRS.

On the video about the prevention of hemorrhagic renal fever: