Respiratory syncytial virus is part of a group of acute infections that affect quite a few big number population mainly early age. One-year-old children occupy the main place among those infected. If in adults the disease is superficial, then in children serious complications can develop.
Definition
This is a virus that causes infections respiratory tract. The tricky thing is that it is difficult to diagnose, as it can easily be confused with a simple cold. On this moment A vaccine has not yet been developed, so the disease is sometimes fatal. In hospitalized patients, the appearance of bronchitis, whistling and asthma is provoked.
Etiology
The respiratory syncytial virus concentrates in the cytoplasm and, after maturation, begins to bud into the membrane. Belongs to the Paramyxoviridae family and is the only representative of this group that can cause serious illness. Although the various stamps have some antigenic heterogeneity, the variations involve predominantly one of several glycoproteins, but the epidemiological and clinical significance of these differences is unclear. The infection grows in a number of cell cultures, causing the formation of a characteristic syncytium.
Causes
Human respiratory syncytial virus is a disease that is transmitted by airborne droplets. Both sick people and carriers can infect it. Collective and family outbreaks are typical, and cases have also been recorded, often in pediatric hospitals. The spread is widespread and around the clock, most often in winter and spring. The greatest susceptibility is observed in children from 4-5 months to 3 years. At an early age, most children suffer from this disease, since then unstable immunity is observed, repeated cases of the disease are quite common, only in a more erased form. However, after the antibodies (IgA) completely disappear from the body, respiratory syncytial virus may reappear.
Spreads through close contact with infected people. It was analyzed and found that if a sick person sneezes, the bacteria easily spread up to 1.8 m. This group of pathogens can survive on hands for up to 30 minutes, and on objects for several hours.
The pathogenesis of the infection is very similar to the mechanism of development of influenza and parainfluenza, as it is associated with the movement of the disease to the epithelium of the respiratory tract. The respiratory tract is used for penetration, and primary reproduction begins in the cytoplasm of the nasopharynx and then spreads to the bronchi. At this moment, hyperplasia of the affected cells and symplasts occurs. Such phenomena are accompanied by hypersecretion and narrowing of the bronchioles, which subsequently leads to their blockage with thick mucus. Then the development of infection is determined by the degree of flora attachment and respiratory failure.
Symptoms
Respiratory syncytial virus, whose microbiology is complex and difficult to diagnose, is a disease early spring and winter.
To date, it has not been revealed why the lower respiratory tract in children and the upper respiratory tract in adults are affected.
In children, the disease begins with fever, severe pain sore throat and runny nose. Soon other symptoms appear that resemble asthma. The infection is characterized by the following symptoms:
- (more than 40 breaths per minute);
- bluish tint to the skin (cyanosis);
- sharp and frequent cough;
- heat;
- intermittent and uneven breathing;
- lobar seals;
- piercing breaths and wheezing;
- difficulty breathing.
Lower respiratory tract infections occur when the bronchioles become swollen. If at this moment the patient experiences problems with the oxygen supply, then it is imperative to consult a doctor for immediate medical care. Such ailments most often appear in children under one year of age, and they quickly worsen.
Classification
Exists a large number of factors by which respiratory syncytial virus can be characterized, namely:
- typical- rhinitis, laryngitis, pneumonia, nasopharyngitis, bronchilitis, bronchitis, segmental pulmonary edema and otitis develop;
- atypical- erased or asymptomatic course of the disease.
There are 3 main forms of the disease.
1. Lightweight, occurs more often in adults and school-age children. Manifests itself as moderate nasopharyngitis, respiratory failure is not observed. Most often, body temperature remains normal or rises slightly, but literally by a few degrees. Signs of intoxication are completely absent.
2. Medium-heavy, symptoms can be observed acute bronchitis or bronchiolitis, accompanied by obstructive syndrome and respiratory failure. The patient has oral cyanosis and shortness of breath. If a child is sick, he may be overly restless, drowsy, excited or lethargic. Slight enlargement of the liver or spleen is common. The temperature is often elevated, but sometimes it is normal. Moderate intoxication is observed.
3. Heavy, at this moment bronchiolitis and obstructive bronchitis develop. There is severe lack of air, which can only be helped by an oxygen mask for breathing. Whistles and noises can be heard, there is pronounced intoxication and a strong enlargement of the liver and spleen.
The severity criteria most often include the following characteristics:
Presence of local changes;
- difficulty breathing.
According to the nature of the flow:
Smooth - absence of bacterial complications;
- unsmooth - the appearance of pneumonia, sinusitis and purulent otitis media.
Story
Respiratory syncytial virus, the symptoms of which can be confused with other diseases, was identified in 1956 by Dr. Morris. He, observing a chimpanzee who was diagnosed with rhinitis, found a new infection and named it CSA - Chimpanzeecoriraagent (the causative agent of chimpanzee runny nose). During the examination of the sick employee who was caring for the monkey, an increase in antibodies very similar to this virus was noticed.
In 1957, R. Chenok isolated a similar pathogen from sick children and determined that it was he who was responsible for causing bronchitis and pneumonia. After this, until today, scientists have been unsuccessfully trying to develop a vaccine.
Diagnostics
The clinical definition of the disease is problematic due to its similarity to other ailments. In adults, the most common symptoms are bronchitis and pneumonia. During laboratory research are used that allow the detection of antibody titer. If necessary, the doctor prescribes x-rays and specific laboratory tests, for example, virological testing of nasopharyngeal swabs.
Therapy
Patients who have been diagnosed with respiratory syncytial virus are prescribed comprehensive treatment in order to strengthen the body. Bed rest is recommended for the entire period of exacerbation. Hospitalization is indicated for children with severe forms of the disease, children preschool age with moderate severity and persons who have complications. Required condition is to have an age-appropriate diet. It should include mechanically and chemically gentle food, full of various microelements and vitamins.
It is also carried out, which is characterized by the use of drugs such as leukocyte human interferon, “Anaferon”, “Grippferon” and “Viferon”. At severe forms It is recommended to take "Immunoglobulin" and "Ribavirin", the price for it varies from 240-640 rubles, depending on the dosage. The drug “Synagis” helps perfectly to prevent the occurrence of consequences of bronchitis. If a bacterial complication is detected, then antibiotic therapy is indicated.
Broncho-obstructive syndrome is well relieved by symptomatic and pathogenetic treatment. In this case, an oxygen breathing mask is used to relieve severe symptoms and simplify the air supply.
Required for complications. After pneumonia, it is recommended to carry out examinations after 1, 3, 6 and 12 months until complete recovery. Preventive diagnostics is necessary after recurrent bronchitis and is prescribed after a year of amendment. If necessary, a consultation with an allergist or pulmonologist is attended, and laboratory tests are also performed.
Treatment of children
Children always get sick more difficult, and the consequences are much more serious than in adults, so therapy must be thorough and intensive.
Antiviral:
- “Ribavirin”, the price of this drug, as described earlier, is affordable, so it won’t put a big dent in the parents’ pockets;
- Arbidol, Inosine, Tiloran and Pranobex are also often prescribed.
Syndromic therapy must be carried out in accordance with the appropriate protocols for the treatment of acute respiratory failure, bronchitis and Croup syndrome.
Basic antihomotoxic therapy:
- “Grip-Heel”, “Engistol” (an initiating scheme is used);
- “Euphorbiumcompositum C” (nasal spray);
- “Lymphomyosot”.
Additionally:
- “Viburkol” ( rectal suppositories);
- “Echinacea compositum C” (ampoules);
- “Angin-Heel S”;
- “Traumel S” (tablets).
All these remedies are excellent in combating respiratory syncytial virus in children.
First actions
In order to quickly defeat the disease, it is necessary to correctly respond to the symptoms that appear, so that you can get the help you need if necessary.
1. You should consult a doctor if a small child develops symptoms of ARVI, namely a sore throat, runny nose and severe wheezing.
2. Must be called ambulance, if there is a high temperature, intense noises, difficulty breathing and a general serious condition.
You need to contact doctors such as a therapist and an infectious disease specialist.
Complications
The respiratory syncytial virus has a negative effect on the respiratory tract. The consequences of this disease are considerable, since secondary bacterial flora can join and cause ailments such as:
Sinusitis;
- otitis;
- bronchitis;
- pneumonia;
- bronchiolitis.
Prevention
All viral diseases are difficult to treat, since their symptoms are often hidden. One of the measures is early detection of the disease and isolation of patients until they have fully recovered. During periods of outbreak of such infection Special attention sanitary and hygienic measures are required. In children's groups and hospitals, it is proposed to wear gauze bandages for staff. Children must and systematically disinfect their hands using alkaline solutions.
Towards measures emergency prevention in foci of infection includes the use of drugs such as Anaferon, Viferon, Imunal and various inducers of endogenous interferon.
Immunoprophylaxis includes such drugs as Motavizubam, RespiGam and Palivizubam.
Vaccine
To date, no component has been developed that will prevent this disease. The creation is quite active, experiments began to be carried out in the 1960s, after which the substance was inactivated with formaldehyde and precipitated with alum. This vaccine caused a pronounced formation of serum antibodies, although as a result of use, those tested developed even more serious illness. Living attenuated components cause not very pleasant symptoms or turn into the same virus, only wild type. Today, they are considering a way to purify subunit antibodies against one of the surface proteins or attenuated elements, and then try to adapt them to cold.
Respiratory syncytial infection is given first place. With a relatively mild course in adults, in children age group this infection can lead to the development of severe pneumonia and may cause an unfavorable outcome.
Respiratory syncytial infection (RS infection)– acute infectious viral disease with airborne transmission, caused by a virus of the Paramixoviridae family, characterized by predominant damage to the lower respiratory tract (bronchitis, bronchiolitis, pneumonia).
RSI, target organ
The causative agent of MS infection discovered in 1956 (Morris, Savage, Blont) by culturing material from chimpanzees during an episode of multiple rhinitis among primates. In humans, a similar virus was isolated in 1957 (Chanock, MyersRoizman) during an examination of children with bronchiolitis and pneumonia. The virus owes its name to one feature of its pathological effects, namely: the ability to form syncytia - a network-like structure of cells with cytoplasmic processes among themselves, as well as tropism for cells of the respiratory tract. Thus, the virus was named “respiratory syncytial virus” (hereinafter RSV).
Causes of MS infection
Pathogen– respiratory syncytial virus (RSV) is an RNA virus from the Paramixovieidae family of the Pneumovirus genus. Currently, 2 serological strains of RSV have been isolated (Long and Randall), which do not have clear distinctions in properties, and therefore are classified as one serotype. The virion size ranges from 120 to 200 nm, RSV is distinguished by polymorphism. RSV contains several antigens:
- nucleocapsid B antigen or complement-fixing antigen (promotes the formation of complement-fixing antibodies),
- surface A-antigen (promotes the production of virus-neutralizing antibodies).
Respiratory syncytial virus
The virus contains an M-protein (membrane protein), which is necessary for communication with the membranes of infected cells, as well as F-proteins, GP-protein (attachment proteins), which facilitate attachment to the target cell of the virus with subsequent replication of RSV.
RSV is not very stable in the external environment: even at a heating temperature of 55-60°C it is inactivated within 5 minutes, and instantly when boiled. When frozen (minus 70°) it retains its viability, but cannot withstand repeated freezing. The virus is sensitive to disinfectants - solutions of acids, ether, chloramine. Sensitive to dryness. On the skin of the hands the virus can remain viable for 25 minutes, on objects environment– clothes, toys, tools can remain in fresh secretions from 20 minutes to 5-6 hours.
In the human body, as well as in cell culture in laboratory conditions, RSV has a cytopathogenic effect - the appearance of pseudogiant cells due to the formation of syncytium and symplast (network-like formation of cells with cytoplasmic bridges between them, that is, the absence of a clear boundary between cells and their specific fusion).
Source of MS infection is a sick person and a virus carrier. The patient becomes infectious 1-2 days before the first symptoms of the disease appear and remains so for 3-8 days. The virus carrier can be healthy (without signs of illness) and convalescent after an illness (that is, after recovery, shed the virus).
Mechanism of infection– aerogenic, transmission route– airborne (when sneezing and coughing, an aerosol with viral particles is sprayed within a 1.5-3 meter environment from the patient). The airborne dust route is of little importance due to the low resistance of the virus to desiccation. For the same reason, transmission through household contact through environmental objects is of little importance.
Susceptibility to infection is general and high; children are more often affected. The disease is highly contagious; nosocomial outbreaks of infection have been described in children's hospitals. A winter-spring seasonality has been identified, but sporadic cases are recorded year-round. By virtue of " passive immunity» Infants (up to 1 year) rarely get sick, with the exception of premature babies. By the age of 3, almost all children have already contracted MS infection. During one season, outbreaks of MS infection last from 3 to 5 months.
Immunity after MS infection unstable, short-term (no more than 1 year). Repeated cases of infection in another epidemic season have been described, which can be erased with residual immunity or manifest in the absence of it.
Pathological effects of RSV in the human body
The entry points for infection are the nasopharynx and oropharynx. Here, RSV replicates in the mucosal epithelium. Then it spreads to the lower parts of the respiratory tract - small-caliber bronchi and bronchioles. It is here that the main pathological effect of RSV occurs - the formation of syncytia and symplasts - pseudogiant cells with cytoplasmic partitions between themselves are formed. In the affected area, inflammation and migration of specific cells - leukocytes and lymphocytes, swelling of the mucous membrane, and hypersecretion of mucus appear. All this leads to blockage of the airways with secretions and the development of various types of disorders of the respiratory excursion of the lungs: the exchange of gases (O2, CO2) is disrupted, and a lack of oxygen occurs. All this is manifested by shortness of breath and increased heart rate. Emphysema and atelectasis may develop.
RSV can also cause immunosuppression (immune suppression), which also affects cellular immunity, and on the humoral. Clinically, this may explain the high incidence of secondary bacterial foci during MS infection.
Clinical symptoms of MS infection
The incubation period lasts from 3 to 7 days. Symptoms of the disease are combined into 2 syndromes:
1) Infectious toxic syndrome. The onset of the disease can be acute or subacute. The patient's body temperature rises from 37.5 to 39° and above. The temperature reaction lasts about 3-4 days. Fever is accompanied by symptoms of intoxication - weakness, weakness, lethargy, headaches, chills, sweating, moodiness. Symptoms of nasopharyngitis immediately appear. The nose is stuffy, the skin is hot to the touch, dry.
2) Airway syndrome, first of all, manifests itself as a cough. A cough in patients with MS infection appears on days 1-2 of illness - dry, painful, persistent and prolonged. Along with the cough, the number of respiratory movements gradually increases; on the 3-4th day from the onset of the disease, signs of expiratory dyspnea(exhalation is difficult, which becomes noisy whistling and audible at a distance). Due to the fact that patients are often young children, attacks of suffocation often occur, accompanied by the child’s anxiety, pallor skin, pastosity and swelling of the face, nausea and vomiting. Older children complain of chest pain.
On examination - hyperemia (redness) of the pharynx, arches, back wall pharynx, enlarged submandibular, cervical lymph nodes, injection of scleral vessels, and upon auscultation of the patient there is harsh breathing, scattered dry and wet rales, dullness of percussion sound. Signs of rhinitis in MS infection are mild and are characterized by small mucous discharge. Possible complications respiratory syndrome, and in severe forms, the manifestations are croup syndrome and obstructive syndrome.
The severity of the manifestations is directly dependent on the patient’s age: the younger the child, the more severe the disease.
Light form characterized by a low temperature reaction (up to 37.50), mild
symptoms of intoxication: minor headaches, general weakness, dry cough. A mild form is more often recorded in older children.
The moderate form is accompanied by febrile temperature (up to 38.5-390), moderate symptoms intoxication, persistent dry cough and moderate shortness of breath (1st degree DN) and tachycardia.
The severe form is manifested by a pronounced infectious-toxic syndrome, severe, persistent, prolonged cough, severe shortness of breath (DN 2-3 degrees), noisy breathing, circulatory disorders. On auscultation there is an abundance of fine bubbling rales and crepitus of the lungs is heard. The severe form is most often observed in children of the first year of life, and the severity is more related to the phenomena of respiratory failure than to the severity of intoxication. In rare cases, pathological hyperthermia and convulsive syndrome are possible.
The duration of the disease is from 14 to 21 days.
In the analysis of peripheral blood, leukocytosis, monocytosis, the appearance of atypical lymphomonocytes (up to 5%), a neutrophil shift to the left is noted when a secondary bacterial infection, increased ESR.
Peculiarities of symptoms in newborns and premature babies: a gradual onset is possible, mild fever, and a persistent cough appears against the background of nasal congestion, which is often confused with whooping cough. Children are restless, sleep little, eat poorly, lose weight, symptoms of respiratory failure quickly increase, and pneumonia develops quite quickly.
Complications and prognosis of MS infection
Complications of MS infection may include diseases of the ENT organs, more associated with the addition of secondary bacterial flora - otitis media, sinusitis, pneumonia.
The prognosis for a typical uncomplicated course of MS infection is favorable.
Diagnosis of MS infection
Diagnosis of respiratory syncytial viral infection is based on:
1) Clinical and epidemiological data. Epidemiological data include contact with an ARVI patient, presence in in public places, places of great crowding. Clinical data include the presence of 2 syndromes - infectious-toxic and respiratory, and most importantly - the peculiarity of the respiratory syndrome in the form of the development of bronchiolitis (see description above). Presence of the above-mentioned signs before the age of 3 years. Differential diagnosis should be carried out with the entire group of acute respiratory viral infections, laryngitis, tracheitis of various etiologies, and pneumonia.
2) Laboratory data – general analysis blood: leukocytosis, monocytosis, increased ESR, detection of atypical lymphomonocytic cells (5%), possibly a neutrophilic shift to the left.
3) Instrumental data - radiography chest: strengthening of the pulmonary pattern,
compaction of the roots of the lung, in places emphysematous areas of the lung.
4) Specific laboratory data:
- virological study nasopharyngeal swabs using RIF, express methods;
- serological blood test for antibodies to RSV using a neutralization reaction, RSK, RTGA in paired sera with an interval of 10-14 days and identifying an increase in antibody titer.
Treatment of MS infection
1) Organizational and routine measures: hospitalization of patients with moderate and severe forms of the disease, bed rest for the entire febrile period.
2) Drug therapy includes:
Etiotropic therapy:
- antivirals(isoprinosine, arbidol, anaferon, cycloferon, ingavirini others) depending on the age of the child;
- antibacterial agents prescribed for proven bacterial infection or pneumonia and only by a doctor.
Pathogenetic treatment:
- antitussive, expectorant and anti-inflammatory syrups (erespal, lazolvan, bromhexine, sinekod, mixtures with marshmallow root, with thermopsis);
- antihistamines (Claritin, Zyrtec, Zodak, Cetrin, Suprastin, Erius and others);
- local therapy(nazol, nazivin and others for the nose, falimint, faringosept and others for the throat).
Inhalation therapy – steam inhalations with herbs (chamomile, sage, oregano), alkaline inhalation therapy, use of nebulizers with medications.
- If necessary, prescribe glucocorticosteroids.
Prevention of MS infection
There is no specific prevention (vaccination).
Prevention includes epidemiological measures (timely isolation of the patient, timely initiation of treatment, wet cleaning of the room, antiviral prophylaxis of contacts - arbidol, anaferon, influenza and other drugs); hardening of children and propaganda healthy image life; prevention of hypothermia during the epidemic season of infection (winter-spring).
Infectious disease doctor N.I. Bykova
Causes
Respiratory syncytial infection is widespread; According to various data, the share of infection cases in the structure of the overall incidence of acute respiratory viral infections ranges from 3 to 16%. Although both children and adults can get sick, the virus is extremely dangerous for young children. Observations have shown that when an infected child appears in a group of children's institutions, all other children under the age of 1 year become ill.
The highest incidence rates are observed in the winter and spring months, but registration of a case of infection is possible at any time of the year. The forms of the disease can be different - there are both lesions of the upper respiratory tract, typical of uncomplicated ARVI, and severe bronchiolitis and pneumonia. Older children and adult patients most often easily tolerate the disease - in contrast to children in the first 6 months of life.
The causative agent of respiratory syncytial infection is a virus belonging to the Paramyxoviridae family. It is called the RS virus, RSV infection and is classified as a group of pathogens that cause ARVI (acute respiratory viral infections) in children and adults. Sensitive to the influence of the external environment, quickly inactivates at a temperature of about 55 ° C (on average in 5 minutes). Contains ribonucleic acid (RNA), causes the formation of syncytium, or pseudogiant cells, in tissue culture.
Respiratory syncytial virus is transmitted by airborne droplets (during coughing, sneezing), through contact and household contact (by shaking hands, using any objects touched by an infected person - for example, toys).
The source of infection is a sick person, and the “entry gate” is epithelial cells upper sections respiratory tract.
Risk factors for severe MS infection have been identified:
In children under 1 year of age, respiratory syncytial virus causes lung damage with episodes of apnea (stopping breathing).
Pathogenesis
Penetration of the PC virus into epithelial cells leads to their death. Pathological changes also include:
- edema, thickening of the walls of the bronchi;
- necrosis of the tracheobronchial epithelium;
- blockage of the lumen of the bronchi with mucous lumps and epithelium;
- formation of atelectasis;
- formation of immune complexes.
The process is characterized by rapid progression, with a high probability of spreading to the lower parts of the respiratory system.
The RS virus is able to suppress the activity of the interferon system, which slows down the formation of the immune response. Secondary immunodeficiency leads to weakened immune defense and an increased risk of bacterial infection.
Symptoms
The incubation period for infection with respiratory syncytial virus infection lasts from 3 to 6 days. The course of the disease largely depends on age. Adults tolerate RSV infection easily in the form of classic ARVI without severe intoxication. Patients are concerned about:
- weakness, moderate lethargy;
- headache;
- increase in body temperature to 37.5-38 °C;
- nasal congestion;
- sore throat;
- dry paroxysmal cough;
- dyspnea.
A non-productive cough turns into a wet cough after a few days. Even after the fever disappears, it can persist for 3 weeks - this is one of the typical signs of MS infection. As the condition worsens, patients complain of shortness of breath and a feeling of heaviness in the chest.
Bronchiolitis - inflammatory disease lower sections respiratory system, characterized by damage to small bronchi and bronchioles. Children under 2 years of age are affected, although in the vast majority of cases bronchiolitis is recorded in patients no older than 9 months. One of the most likely provoking etiological agents is respiratory syncytial virus. Symptoms usually appear a few days after the onset of ARVI (runny nose, fever), the clinical picture includes:
- Severe weakness, lethargy or agitation.
- Excruciating headache.
- Loss of appetite.
- Fever (37.5-38.5 °C).
- Spasmodic cough, runny nose, pharyngitis.
Sometimes vomiting and stool upset occur - usually in the first day after the onset of clear symptoms. The patient's breathing is frequent, short, whistling with difficulty exhaling; accompanied by the participation of auxiliary muscles. There is swelling of the chest, a gray-cyanotic tint of the skin, and bluish lips. When auscultating the lungs, you can hear dry whistling and moist rales on both sides. The cough is initially dry and hoarse; after it acquires a productive character, sputum is difficult to separate.
Diagnostics
As a rule, only respiratory syncytial infection in children requires rapid confirmation of the diagnosis. Adults tolerate it like a regular acute respiratory viral infection without the need for hospitalization and decision-making on tactics urgent measures. Used:
- general blood analysis;
- chest x-ray;
- pulse oximetry;
- linked immunosorbent assay;
- immunofluorescence method;
- polymerase chain reaction.
The choice of studies is made by the attending physician. 
Treatment
Patients are treated on an outpatient or inpatient basis. Hospitalization required:
- children under 6 months of age;
- children with episodes of apnea;
- patients with signs of respiratory failure;
- patients with a need for constant sanitation of the respiratory tract;
- in the presence of severe concomitant pathologies.
It is also recommended to hospitalize children who show signs of malnutrition and feeding difficulties. Social indications are important - the absence of persons who can care for the patient during illness, the patient being in constant contact with other children in orphanages.
When infected with respiratory syncytial virus, treatment includes the following measures:
- Hydration, that is drinking plenty of fluids, administration of glucose-saline solutions intravenously through a nasogastric tube.
- Inhaled short-acting B2-agonists (salbutamol).
- Clearing the nose of mucus.
- Oxygen therapy according to indications.
Antibacterial therapy is used only if the patient has a proven bacterial infection.
Mucolytics (ambroxol) should not be used without a doctor's prescription, since the volume of bronchial secretions increases and the symptoms of respiratory failure worsen. In addition, the secretion is liquid, and there is no need to further liquefy it.
The feasibility of using glucocorticosteroids, both inhaled and systemic, is discussed. It is not recommended to include vibration massage in the treatment regimen for bronchiolitis due to its low effectiveness.
In case of severe respiratory failure, apnea, mechanical ventilation (artificial ventilation) is used. The need to prescribe ribavirin as an antiviral drug is determined by the doctor.
Prevention 
- preservation breastfeeding not less than during the first 6 months of life;
- prevention of passive smoking;
- reducing the frequency and time of stay in crowded places;
- limiting and avoiding contact with persons who have symptoms of ARVI;
- frequent hand washing, avoiding touching your eyes, nose and mouth before performing hygiene procedures.
Children at risk of severe RS infection are immunized with palivizumab (monoclonal antibodies to the RS virus).
Respiratory syncytial virus infection (RS infection)- acute anthroponotic viral disease with predominant damage to the lower respiratory tract.
Brief historical information
The causative agent of the disease was first isolated by D. Morris from chimpanzee monkeys during an epizootic of rhinitis (1956). The causative agent was originally named “monkey coryza virus.” Somewhat later, R. Chanock et al. isolated a similar virus in children suffering from bronchiolitis and pneumonia (1957). The virus received its modern name due to its ability to cause the formation of syncytial fields in tissue culture cells.
Etiology
The causative agent is an RNA genomic virus of the genus Pneumovirus families Paramuho-viridae. The virus has a surface A antigen, which causes the synthesis of neutralizing antibodies, and a nucleocapsid B antigen, which induces the formation of complement-fixing antibodies. The virus causes the formation of syncytium, or pseudogiant cells, in vitro And in vivo. Virions are inactivated at 55 °C for 5 minutes, at 37 °C for 24 hours. The pathogen tolerates single freezing at -70 °C. The virus is completely destroyed at pH 3.0, as well as during slow freezing. Sensitive to ether, acids and detergents.
Epidemiology
Reservoir and source of infection- person (patient or carrier). The virus begins to be released from the nasopharynx of patients 1-2 days before the onset of clinical manifestations and is present until 3-6 days of clinically pronounced disease. Convalescent and “healthy” carriage is expressed.
Pathogen transmission mechanism- aerosol, transmission factor- air.
Natural sensitivity of people high, especially in children. Post-infectious immunity is unstable. Possible recurrent illnesses after few years.
Basic epidemiological signs. PC infection is widespread and is recorded all year round, with the greatest increase in incidence in the winter and spring months. During the inter-epidemic period, sporadic cases of diseases are noted. Most often, PC infection is observed in young children (up to 1 year), although adults are also susceptible to it. When the infection is introduced into children's institutions, almost all children under the age of 1 year become ill. Epidemics are characterized by high intensity; in most cases they last 3-5 months.
Pathogenesis
Upon aerogenic entry into the human body, the respiratory syncytial virus penetrates into the epithelial cells of the mucous membrane, including the nasopharynx, provoking the development inflammatory process. However, especially in children younger age, the most typical lesion is the lower respiratory tract with the process spreading to the trachea, bronchi and especially bronchioles and alveoli. As a result of virus reproduction, necrosis of epithelial cells of the bronchi and bronchioles and lymphoid peribronchial infiltration occur. With the progression of inflammation with a pronounced allergic component, multicellular outgrowths of the epithelium are formed, mononuclear exudate is released into the lumen of the alveoli, which leads to obstruction of the respiratory tract, filling of the alveoli, and the development of atelectasis and emphysema.
Clinical picture
The incubation period varies from several days to 1 week. The disease develops gradually. Depending on the predominant damage to certain parts of the respiratory system, several clinical variants of PC infection are distinguished: nasopharyngitis, bronchitis and bronchiolitis, pneumonia.
In adults and older children it usually develops nasopharyngitis, clinically indistinguishable from similar conditions in other acute respiratory viral infections. On the background low-grade fever bodies note minor manifestations of general intoxication - chilling, moderate headache, weakness, mild myalgia. Patients develop nasal congestion with light serous discharge, a sore throat, sneezing, and dry cough.
When examining patients, mild or moderate hyperemia of the mucous membrane of the nasal passages and the posterior wall of the pharynx, injection of scleral vessels, and sometimes enlargement of the cervical and submandibular lymph nodes are noted. Recovery often occurs within a few days.
Development pathological processes in the lower respiratory tract is more common in young children, but is also possible in adults. From the 3-4th day of illness the patient's condition worsens. Body temperature increases, sometimes reaching high numbers, and the cough gradually intensifies - first dry, and then with mucous sputum. There is a feeling of heaviness in the chest, and sometimes expiratory shortness of breath occurs. Symptoms of suffocation may accompany coughing. When examining patients, conjunctivitis, scleral injection, and sometimes cyanosis of the lips can be noted. The mucous membrane of the nose, oropharynx and posterior pharyngeal wall is moderately hyperemic, with slight granularity. Hard breathing and a large number of dry rales in various parts are heard in the lungs. This symptomatology corresponds to the picture acute bronchitis.
Pneumonia can develop in the first days of PC infection even in the absence of pronounced signs of intoxication and normal temperature bodies. In this case, pneumonia is considered as a consequence of the reproduction of respiratory syncytial virus. It is characterized by a rapid increase in respiratory failure. Within several hours, general weakness and shortness of breath increase. With the development of asthmatic syndrome, characteristic of PC infection, especially in young children, shortness of breath may become expiratory in nature (with prolonged wheezing exhalation).
The skin becomes pale, cyanosis of the lips and nail phalanges occurs. Tachycardia increases. With percussion of the lungs, alternating areas of dullness and boxed sound can be detected; with auscultation, diffuse dry and moist rales of different sizes are detected. X-ray can reveal increased pulmonary pattern, areas of emphysema and atelectasis.
The development of pneumonia in later stages of PC infection may be associated with activation of its own bacterial flora; in this case it is regarded as a complication. Pneumonia most often affects the lower lobes of the lungs and can be different in nature: interstitial, focal, segmental.
Differential diagnosis
PC infection should be distinguished from other acute respiratory viral infections, influenza and pneumonia of various etiologies. The disease develops gradually. Nasopharyngitis, bronchitis and bronchiolitis As clinical variants, PC infection is practically indistinguishable from similar conditions in other acute respiratory viral infections. Early viral pneumonia characterized by a rapid increase in respiratory failure and the development of asthmatic syndrome, characteristic of MS infection.
Laboratory diagnostics
Virological studies in clinical practice rarely used (isolation of the virus from nasopharyngeal swabs, detection of its antigens in the epithelium of the respiratory tract using RIF). When setting up the neutralization reaction (RN) and other serological reactions, used in the diagnosis of acute respiratory viral infections (RSK, RTGA, etc.), the diagnosis is retrospectively confirmed by an increase in antibody titer.
Complications
Complications are associated with the activation of one’s own bacterial flora. The most common of them are pneumonia and otitis media. Children's development is dangerous false croup. The prognosis of the disease is usually favorable; When pneumonia develops in infants, the prognosis can be serious.
Treatment
Uncomplicated cases are treated at home using symptomatic remedies. If it is impossible to quickly determine the etiology of pneumonia (the addition of secondary bacterial flora is possible), antibiotics and sulfonamide drugs are used. Asthmatic syndrome is relieved by parenteral administration of ephedrine, aminophylline, antihistamines, in severe cases - glucocorticoids.
Prevention and control measures
Similar to those for influenza. Specific prevention not developed.
