The structure of the incidence and modern approaches to the treatment of acute respiratory viral infections in children
Undoubtedly, acute respiratory infections (ARI) invariably occupy a leading place in the structure of infectious pathology, especially among children. In Russia, approximately 70–80 thousand diseases are registered annually per 100 thousand of a population of a given age (3.3 times higher than in adults) with no downward trend, while the frequency of influenza during a seasonal increase in the incidence is not always more frequent, and sometimes less frequently than ARI of another etiology in total.
ARIs are not a mild “cold”, which we constantly hear from the TV screen and read on the Internet — they are acute infections with varying severity of the course, caused mainly by viruses belonging to at least 7 families (Orthomyxoviridae, Paramyxoviridae, Picornaviridae, Coronaviridae, Reoviridae, Parvoviridae, Adenoviridae). It should be noted that the causative agents of the common cold do not exist at all, and this concept has nothing to do with medicine.
The spectrum of pathogens may be different, but, as a rule, it is due to the season and age of the observed. So, respiratory syncytial (MS) and rhinoviruses, hemophilic bacillus circulate more often in maternity hospitals and wards of newborns, adeno-, MS, and parainfluenza viruses in preschool groups, among schoolchildren – adenoviruses, pneumonia mycoplasma. Influenza virus dominates in patients of any age during the epidemic rise of influenza. In approximately 25–30% of cases, especially in newly created groups (a group of a preschool institution, the first grade of a school, a hospital ward, a barracks), several pathogens simultaneously participate in the infectious process, due to the “mixing” effect.
Despite the common entrance gate for acute respiratory viral infections of any etiology (mucous membrane of the nasal passages and nasopharynx) with the obligatory development of local inflammation (rhinitis, pharyngitis), these infections are notable for significant polymorphism of clinical symptoms and the absence, apart from influenza viruses, of sensitivity to modern anti-influenza drugs (neuraminidase inhibitors) ), currently widely used in the treatment of influenza. It is proved that the severity and speed of development of clinical manifestations, as well as the severity of acute respiratory viral infections and the frequency of complications are due to both the pathogenicity of the pathogen and the activity of patient protection factors.
Table 1. Differential clinical and epidemiological characteristics of ARI of various etiologies
Types of ARVI
Influenza is also SARS, the most common and severe. It is caused by RNA-containing viruses that belong to the Orthomyxoviridae family (genus Influenzae), including influenza viruses of types A, B and C. The ability of viruses to antigenic variation determines the high susceptibility of the population and the involvement of all age groups of adults and children in the epidemic process. It was noted that if earlier epidemic subtypes of viruses succeeded each other, then in recent decades there has been a simultaneous circulation of influenza A (H1N1), A (H3N2) and B viruses . The disease begins against a background of complete health, less often after a short illness. The main manifestations: general intoxication syndrome and symptoms of respiratory tract damage with the predominance of the former over the latter. Light forms are possible only in vaccinated. In severe forms of influenza, the process progresses rapidly with the development of manifestations of a systemic inflammatory reaction and hemorrhagic syndrome with possible hemorrhage in vital organs: lungs, adrenal glands, brain, intestines, etc. It is possible to develop an infectious toxic shock, one of the manifestations of which is due to tissue hypoxia and acidosis is primarily a lesion of the central nervous system in the form of a neurotoxic syndrome (toxic encephalopathy) with cerebral edema and impaired cerebral hemodynamics. Possible development of toxic hemorrhagic pulmonary edema or acute respiratory distress syndrome, which is based on damage to the alveoli-capillary membrane and an increase in capillary permeability for large molecules. Severe microcirculatory disorders due to the significant vascular content often occur in the proximal gastrointestinal tract (GIT).
Parainfluenza is caused by RNA viruses belonging to the Paramyxoviridae family (Respirovirus genera (types 1 and 3). The main localization of viruses is the laryngeal mucosa. The microcirculatory disorders described above are not characteristic for parainfluenza. Catarrhal laryngotracheitis (bronchitis) usually develops. changes in the larynx . Severe forms of parainfluenza are usually associated with the development of acute stenosing laryngotracheitis (ALT), which may be caused by a reflex spasm of the muscles of the larynx and trachea, edema and infiltration. walkie-talkie of the mucous membrane and lining of the larynx, obstruction of the respiratory tract with mucopurulent contents.Changes in the lungs are usually less pronounced.