Modern Features of the Course of Acute Respiratory Infections in Children (Superinfection, Outcomes)

The dissertation is devoted to the study of modern features of the course of acute respiratory infections (ARI) in early childhood, including problems of superinfection and adverse outcomes of the disease. The research was conducted at the Kyrgyz-Russian Slavic University (Bishkek) and encompasses the clinical manifestations of ARI, the frequency of nosocomial superinfection, risk factors of fatal outcomes, and the structure of mortality among children in the first three years of life. The author analyzes the role of biological, social-hygienic, and medical-organizational factors influencing the prognosis of the disease and proposes algorithms for the management of patients at the levels of primary and inpatient care.

Relevance of the problem. Acute respiratory infections (ARI) currently occupy the first place in the structure of morbidity and mortality among children in the first two years of life worldwide [12]. In countries with an unstable political and economic system, which includes Kyrgyzstan, mortality in childhood from ARI amounts to approximately 30% [29,30], and in Kyrgyzstan it exceeds 40% [38]. The achievements of modern pediatric pulmonology have made it possible to improve the outcomes and prognosis of acute respiratory diseases in children. However, despite significant successes in this area, the diagnosis and treatment of acute respiratory diseases and pneumonias remain not fully resolved problems of pediatrics, owing to their high frequency and the absence of reliable guidelines in treatment tactics.

In modern practice, the diagnosis of pneumonia in children requires etiological clarification of the diagnosis, determination of the localization of the pathological process, degree of severity, and complications. The nature of the causative agent and its sensitivity to antibiotics largely depend on the conditions in which the infection occurred. In this regard, community-acquired and nosocomial pneumonias, perinatally acquired pneumonia, and pneumonia in patients with immunodeficiency are distinguished. This has been reflected in the classification of clinical forms of bronchopulmonary diseases in children adopted in 1995. The scientific literature contains data on the fruitfulness of searching for refined diagnostic criteria for ARVI and pneumonias. Nevertheless, the problem is far from being resolved, which is confirmed by the high frequency of hyperdiagnosis of pneumonias noted by a number of researchers [43,110].

A diagnosis of pneumonia is made in virtually all deceased children, especially in early age, regardless of whether it is the primary, competing, or concomitant disease [101].

Fatal outcomes in acute pneumonia in the majority of children can be prevented. Death from pneumonia occurs most often in children who have serious concomitant pathology, congenital malformations of various organs and systems, immunodeficient states, etc. Up to 75% of fatal outcomes in pneumonias in early childhood are attributable to nosocomial pneumonias [68,116]. All this requires the development of well-founded approaches to the organization of medical care and the formulation of well-grounded interpretations of statistical data. Closely linked to the questions of outcomes and prognosis of various forms of ARVI is the problem of optimizing therapy, reducing pharmacological loads, which are often excessive and can lead to the exacerbation of atopic reactions and suppression of the immune system [21].

To date, there are no clear data on the influence of antipyretic agents and antibiotics on the course of ARVI, although the possible negative consequences of prescribing these drugs are well known. Thus, there is a need to develop clear indications for the prescription of antibiotics to children with severe forms of ARVI involving the lower respiratory tract. The study of this question is of extreme relevance.

An important issue is the prevention of respiratory viral superinfections in the hospital. The literature publishes data on the more frequent development of pneumonia in mixed viral infection, caused simultaneously by 2-3 pathogens, superimposing on one another. Pneumonias that develop in the late stages of ARVI run in severe forms; therefore, it is desirable to change the established practice of wide hospitalization of young children with ARVI, especially in cases of their non-severe course.

The problems we have identified have a clearly expressed medical and social significance and therefore require further research in order to develop measures aimed at reducing the negative impact of ARVI on the level of childhood morbidity and the frequency of fatal outcomes.

The search for effective methods of prevention and treatment of ARVI is also necessitated by the deep socio-economic changes that have taken place in Kyrgyzstan over the last decade, and in connection with the fundamental reform of the system of medical care delivery to the population.

Objective of the work. Based on a comprehensive analysis of the clinical features and risk factors of adverse outcomes of ARI, to scientifically substantiate measures aimed at the prevention of nosocomial infection and the reduction of mortality from ARI in early childhood.

Research tasks:

1. To study the features of the course and outcomes of ARVI in early childhood depending on the degree of severity of initial clinical manifestations and the treatment administered.

2. To study the causes and frequency of development of nosocomial superinfections in children with ARVI and pneumonia.

3. To study the structure of mortality in children from ARVI and pneumonia.

4. To identify the most characteristic and significant for Kyrgyzstan biological, social-hygienic, and medical risk factors of adverse outcome of the disease.

5. To develop optimal indications for the hospitalization of children with ARVI and measures aimed at reducing nosocomial superinfections.

Scientific novelty.

• For the first time in the republic, on the basis of the conducted analysis of clinical features of ARI, the following have been established:

- absence of a correlation between the severity of manifestations of initial symptoms of the disease and the subsequent course and outcome of ARI;

- low percentage (4.4%) of development of bacterial complications during the main disease and an increase (6.7%) of complications after nosocomial superinfection;

- absence of a dependence between the use of antibacterial and antipyretic agents and a positive dynamics of ARI.

• The frequency of nosocomial infection (18.5%) and its main causes have been established: an unfavorable premorbid background, prolonged duration of children's stay in hospital, and unfavorable conditions of hospitalization.

• It has been proven that in the structure of mortality from ARI in early childhood, pneumonia (40.5%) prevails as the primary disease and is the most frequent concomitant disease (42.2%) contributing to the development of an adverse outcome in other acute infectious diseases.

• Medical-organizational (defects in diagnosis and therapy at the prehospital stage), biological (damage to the CNS, hypotrophy, anemia, complicated pregnancy, the first year of the child's life), and social (low social status of the family, low sanitary literacy of parents) risk factors for the development of adverse outcomes of ARI in modern conditions have been identified.

• For the first time, an algorithm for the management of patients with ARI has been developed at the levels of primary and inpatient care.

Practical significance of the research.

1. New information has been obtained on the frequency of nosocomial superinfection of ARVI in early childhood.

2. Differentiated indications for the hospitalization of children with ARVI have been proposed, as well as the necessity of earlier discharge of patients with uncomplicated ARVI from hospital in order to reduce the risk of superinfection.

3. Risk factors for the development of severe forms of ARI with an adverse outcome have been identified, which are indications for mandatory hospitalization in hospital.

4. An algorithm for the management of patients with ARI has been developed at the level of primary and inpatient care.

5. The inappropriateness of a course prescription of antipyretic agents and the use of antibacterial agents in ARVI has been demonstrated.

Propositions to be defended

1. In early childhood, no correlation has been established between the degree of severity of initial symptoms and the subsequent course of ARI; clinically, the absence of a positive influence of antipyretic and antibacterial agents on the dynamics and course of ARI has been confirmed.

2. The causes of nosocomial infection are associated with unjustifiably wide hospitalization of children with a non-complicated course of ARVI and pneumonia, prolonged hospital stay, and conditions of hospitalization.

3. In the structure of mortality from ARI, acute pneumonia prevails both as an independent disease and as a concomitant pathology in early childhood. Elimination of preventable factors of adverse outcome will make it possible to reduce the level of mortality from ARI and pneumonia.

Author's personal contribution

All basic material of the research was collected and processed personally by the executor of the work, as a result of which the main conclusions and findings were formulated.

Validation of the work.

The main provisions of the dissertation were reported and discussed at the International Conference on Human Pathology and Ecology (Jalalabad, October 17-18, 2004).

The main results of the dissertation research were reported and discussed at an interdepartmental meeting of the departments of pediatric infectious diseases of KGMA, pediatrics of KRSU, and infectious and dermatovenereal diseases of KRSU (December 2005).

Implementation of the results.

The results of the research have been implemented in the work of the Republican Clinical Infectious Hospital (RCIH), the National Center for Pediatrics and Pediatric Surgery, departments of respiratory infections, and polyclinics of the republic.

The materials of the dissertation are included in the thematic courses and classes for students and clinical residents of KRSU.

Publications. Six articles have been published on the topic of the dissertation.

Structure and volume of the work. The dissertation includes: introduction, analysis of literature data, a chapter on materials and methods of research, three chapters of original research, conclusion, findings, practical recommendations, bibliography, and appendix. The work is presented across 160 pages, including the appendix, illustrated with 57 tables and 8 figures. The bibliography includes 193 sources, including 57 works by foreign authors.