Respiratory syncytial virus infection (RS ) infection - Causes, Symptoms and Treatment .MF .
Causes of MS infection
Symptoms and complications
Diagnosis Treatment Prevention
respiratory syncytial infection enters the group of acute respiratory viral infections that affect the population annually rather extensive group of mostly early childhood.Among infants the first place in the group allocated SARS respiratory syncytial virus infection.With relatively less severe in adults, in the pediatric age group, this infection can lead to severe pneumonia and may cause an adverse outcome.
respiratory syncytial infection (RS-infection) - an acute infectious viral disease with airborne transmission, caused by a virus semeystvaParamixoviridae characterized by a primary lesion of the lower respiratory tract (bronchitis, bronchiolitis, pneumonia).
RCI, target organ
Pathogen PC infection opened in 1956 (Morris, Savage, Blont) when cultured material from chimpanzees during numerous episodes of rhinitis among primates.A person like a virus isolated in 1957 (Chanock, MyersRoizman) when examinin
Causes of PC infection
Pathogen - respiratory syncytial virus (RSV) - RNA virus of the family Paramixovieidaeroda Pneumovirus.Nowadays serological allocated two RSV strains (Long and Randall) which do not have clear lines on the properties, therefore, assigned to one serotype.virion size ranges from 120 to 200 nm distinguishes RSV polymorphism.RSV is composed of multiple antigens:
- The nucleocapsid antigen or complement-fixing antigen (contributes to the formation of complement-fixing antibodies),
- A surface-antigen (contributes to the development of neutralizing antibodies).
Respiratory syncytial virus
The virus has a composition of M-protein (membrane protein) required for communication with the membranes of infected cells, as well as GP-F- Beloki protein (securing proteins) to facilitate attachment to kletke-target of the virus followed by replication of RSV.
RSV little stable in the environment: heating at a temperature of 55-60 ° C is inactivated for 5 minutes at the boil instantaneously.When freezing (-70 °) retains its viability, but can not withstand repeated freezing and thawing.The virus is sensitive to disinfectants - diluted acids, ester, chloramine.Sensitive to drying.On the skin of the hands of the virus can be maintained in a viable state for 25 minutes at ambient environment objects - clothes, toys, tools, fresh excreta can be maintained from 20 minutes to 5-6 hours.
In humans, as in in vitro cell culture, RSV has a cytopathogenic effect - the appearance psevdogigantskih cells by syncytium formation and symplast (reticular formation of cells with cytoplasmic bridges between them, that is, the lack of clear borders between the cells and their specific merger).
source PC infection is a sick man and a virus carrier.The patient becomes infectious for 1-2 days before the onset of symptoms and remains so for 3-8dney.Infected with HIV can be healthy (disease-free) and convalescents recovering from illness (ie after recovery excrete the virus).
mechanism infection - aerogenic, route of transmission - airborne (when sneezing and coughing occurs splashing spray viral particles in 1,5-3hmetrovom surrounded by the patient).Airborne dust path is of little importance because of the low stability of the virus to drying.For the same reason has little value transfer contact-household way through the surrounding furnishings.
universal susceptibility to infection and the high, often ill child population.The disease is highly contagious, described nosocomial outbreaks of infection in children's hospitals.Revealed the winter-spring season, but sporadic cases recorded throughout the year.By virtue of "passive immunity" infants (under 1 year), rarely get sick, except for premature babies.Before 3hletnego age almost all the children have perebolevayut PC infection.Within one season PC outbreaks last from 3 to 5 months.
Immunity after undergoing PC infection unstable, short-term (less than 1 year).We describe the cases of re-infection epidemic season to another, which may occur at a residual immunity erased or manifest in the absence thereof.
pathological processes in the human RSV
Atrium is the nasopharynx and oropharynx.There RSV replicates in the epithelium of the mucous membrane.Further there it spread to the lower respiratory tract - the bronchi and bronchioles small caliber.This is where there is the main pathological effects of RSV - the formation of syncytia and symplasts - formed psevdogigantskie cells with cytoplasmic partitions between them.In the lesion appears the inflammation and the migration of specific cells - white blood cells and lymphocytes, mucosal edema, mucus hypersecretion.All this leads to blockage of airway secretions and the development of various types of lung disorders respiratory excursion: impaired gas exchange (O2, CO2), there is a lack of oxygen.All this is manifested by shortness of breath and rapid heart rate.Perhaps the development of emphysema, atelectasis.
also RSV can cause immunosuppression (immunosuppression) that affects the cellular immunity and humoral.Clinically, this may explain the greater incidence of secondary bacterial foci in MS infection.
Clinical symptoms of MS infection
The incubation period lasts from 3 to 7 days.Symptoms of the disease combined 2 syndrome:
1) infectious-toxic syndrome. Onset may be acute or subacute.The patient's body temperature rises from 37.5 ° to 39 or higher.Temperature reaction lasts for about 3-4 days.Fever accompanied by intoxication symptoms - weakness, fatigue, lethargy, headache, chills, sweating, moodiness.Immediately appear nasopharyngitis symptoms.The nose is incorporated, the skin feels hot, dry.
2) airway lesions syndrome , primarily manifested cough.Cough in patients with MS infection appears 1-2 day of illness - a dry, painful, hard and long.In addition to the cough gradually increases the number of respiratory movements, on 3-4 day from the beginning of the disease is showing signs of expiratory dyspnea (difficult breathing out, which becomes loud whistling and audible at a distance).Due to the fact that patients often - it is young children, it is often occur attacks of breathlessness, accompanied by anxiety child, pale skin, and swelling pasty face, nausea and vomiting.Older kids complained of chest pain.
When viewed - hyperemia (redness) of the throat, temples, back of the throat, increasing the submandibular, cervical lymph nodes, vascular injection sclera, and in the patient's auscultation hard breathing, scattered dry and moist rales, dullness of percussion zvuka.Priznaki rhinitis whenRS-infection expressed little and are characterized by small mucous secretions.Possible complications of respiratory syndrome, a severe form - manifestations are croup syndrome and obstructive syndrome.
the severity of symptoms is directly dependent on the patient's age: the younger the child, the more severe the disease is.
• Mild form is characterized by low temperature reaction (to 37.50), mild symptoms of intoxication
: slight headache, weakness, dry cough.Mild often recorded in older children.
• Moderate form is accompanied by a febrile temperature (up to 38,5-390), mild symptoms of intoxication, persistent dry cough and mild dyspnea (NAM 1 degree) and tachycardia.
• Severe manifested pronounced infectious-toxic syndrome, severe, persistent, prolonged cough, dyspnea (NAM 2-3 degrees), noisy breathing, circulatory disorders.Auscultation of the abundance of finely wheezing, audible crackling light.Severe occurs most often in infants, and the severity is more related to the phenomena of respiratory failure than with the severity of intoxication.In rare cases, possible pathological hyperthermia and convulsions.
disease duration of 14 to 21 days.
In the analysis of peripheral blood indicated leukocytosis, monocytosis, the appearance of atypical limfomonotsitov (up 5%), neutrophilic shift to the left when joining a secondary bacterial infection, increased erythrocyte sedimentation rate.
Features symptoms in newborns and premature infants: possible gradual onset, mild fever, severe, against congestion in the nose appears persistent cough that is often confused with whooping cough.Children are restless, little sleep, bad eating, lose weight, fast growing signs of respiratory distress, quickly developing pneumonia.
Complications and prognosis of MS infection
Complications PC infections can be ENT diseases more associated with secondary bacterial flora - otitis, sinusitis, pneumonia.
prognosis of typical uncomplicated PC infection favorable.
Diagnosis of MS infection
diagnosis of respiratory syncytial virus infection is made by:
1) Clinical and epidemiological data.Epidemiological data includes contact with SARS patients, the presence in public places, places of great crowding.Clinical findings include the presence of 2 syndromes - toxic and infectious respiratory, and most importantly - a feature of respiratory syndrome in the form of bronchiolitis (see description above.).The presence of the above symptoms before the age of 3 years.Differential diagnosis should be done with the whole group of acute respiratory viral infections, laryngitis, tracheitis various etiologies, pneumonia.
2) Laboratory data - CBC: leukocytosis, monocytosis, increased erythrocyte sedimentation rate, detection of atypical cells limfomonotsitarny (5%), possibly neutrophilic shift to the left.
3) instrumental data - chest X-ray: increased pulmonary pattern,
seal the lung roots, sometimes emphysematous regions of the lung.
4) specific laboratory data:
- virological testing of nasopharyngeal swabs using a RIF, rapid methods;
- serological blood test for antibodies to RSV by a neutralization reaction, RSK, HI in paired serum samples at intervals of 10-14 days, and the identification of an increase in antibody titer.
Treatment of MS infection
1) Organizational and regime activities: hospitalization of patients with moderate to severe form of the disease, bed rest for the entire febrile period.
2) Drug therapy includes:
- causal treatment:
- antivirals (izoprinozin, Arbidol, anaferon, tsikloferon, ingavirin others), depending on the age of the child;
- antibacterial agents are appointed with a proven joining bacterial infection, pneumonia and accession by a doctor.
- Pathogenetic treatment:
- antitussive, expectorant and anti-inflammatory syrups (Erespal, Lasolvan, bromhexine, sinekod, medicine with marshmallow root, with Thermopsis);
- antihistamines (Claritin, Zyrtec, zodak, tsetrin, suprastin, erius and others);
- local therapy (Nazol, nazivin and other nasal Falimint, Faringosept and other throat).
- Inhalation therapy - steam inhalation of herbs (chamomile, sage, oregano), alkaline inhalation therapy, the use of nebulizers with drugs.
- If necessary, the appointment of glucocorticosteroids.
Prevention PC infection
specific prophylaxis (vaccination) is not.
Prevention includes epidemiological events (early isolation of patients, early treatment, wet cleaning of the premises, antiviral prophylaxis contact - Arbidol, anaferon, Grippferon and other drugs);hardening of children and the promotion of healthy lifestyles;Prevention of hypothermia in the epidemic of infection season (winter-spring).
infectious disease doctor Bykov NI