Modern Views on the Prevalence of Pneumonia in Children and the Role of Laboratory Diagnosis: A Review of the Literature

Abstract

An analysis of domestic and foreign literature on the prevalence, causes and mechanisms of pneumonia in children. This article highlights the prevalence and features of the clinic and diagnosis of pneumonia in children based on a review of the literature. Out-of-hospital pneumonia today remains a pressing medical and social problem, often leading to complications and often causing the death of children, both in Ukraine and around the world, so it needs more in-depth diagnosis. It is known that the severity of this disease depends on age, etiology, comorbidity and timely hospitalization. The incidence and prevalence of respiratory diseases is one of the main indicators of health among children in the world. Therefore, the purpose of this research is to analyze foreign and domestic literature sources on the prevalence and search for the most informative diagnostic criteria for pneumonia in young children. More recent meta-analyzes of etiological data indicate a change in the profile of the pathogen, which increases the recognition that community-acquired pneumonia is caused by sequential or simultaneous interaction of more than one microorganism. Given the epidemiology of community-acquired pneumonia and long-term hospital stays, the study and synthesis of data on the diagnostic criteria for community-acquired pneumonia remains relevant. It is currently not possible to identify a single marker or clinical sign that can be used to distinguish bacterial from viral pneumonia. It is important to evaluate all indicators of objective, instrumental and laboratory examination. Based on literature data, cytokine status indicators can be used to prevent the development of complications from pneumonia, prescribe adequate therapy and determine the duration of treatment. There are many other biomarkers that have been linked to the severity of pneumonia in children. According to statistics, a study of children with COVID-19 showed that the blood of patients, especially those with severe disease, has high levels of proinflammatory cytokines, especially IL-6, which during infection may be a key cytokine that causes serious inflammation and acute damage to many organs and systems. In particular, such a biomarker is IL-6 - the only serum cytokine, the presence of which probably correlates with the severity of pneumonia. The relationship between serum IL-6 and IL-10 levels is an important diagnostic criterion for determining the severity of pneumonia in children on admission, which allows screening for the risk of complications and assessing the possibility of rapid recovery. The use of immune and inflammatory markers in children with pneumonia can potentially lead to the development of innovative methods for predicting complications of community-acquired pneumonia and determining the severity. In addition, it has been shown that serum IL-6 levels are significantly reduced in patients with pneumonia during the recovery period, which allows to evaluate the effectiveness of treatment. Procalcitonin is also an important indicator of the inflammatory process. There are conflicting data on the ability of procalcitonin to distinguish between bacterial and viral infections. Given these data, procalcitonin can be used as a diagnostic criterion for the presence of bacterial infection and the appropriateness of antibiotic therapy. Analysis of available scientific works on prevalence features of the clinic and diagnosis of pneumonia in children, showed that the issue of timely diagnosis and differential diagnosis of pneumonia in children is still relevant and requires further research.