Evaluation of viral respiratory pathogens in children aged under five hospitalized with lower respiratory tract infections.

Objective: Lower respiratory tract infections (LRTIs) are responsible for significant morbidity and mortality in children. Viral pathogens are responsible for 50-70% of LRTIs. The real-time multiplex polymerase chain reaction (RT-MPCR) tests allow the simultaneous detection of several different viruses along with some bacterial pathogens and give faster and more reliable results than viral culture. We aimed to describe the disease etiology and the clinical, laboratory, and radiological characteristics of children aged under 5 years who were hospitalized in a tertiary care medical center with LRTIs assayed using an RT-MPCR respiratory pathogen panel, and evaluate the effects of the detection of etiology on treatment and outcome. Methods: This retrospective study was conducted in the tertiary medical health center. The study group comprised all pediatric cases aged under five who were hospitalized due to LRTIs in the pediatric wards and pediatric intensive care unit (ICU) and undergone RT-MPCR analyses between January 2019 and February 2020. RT-MPCR analyses of samples from nasopharyngeal swabs were consecutively evaluated. Results: A total of 65 samples were collected from aged under 5 years who were hospitalized with LRTIs and screened for respiratory viruses. Specimens were collected from pediatric ICU (18.5%) and pediatric wards (81.5%). The overall positive rate was 89.2% (58/65). Forty of the patients (61.5%) were positive for a single pathogen, 15 (23.6%) for two, and three (4.6%) for three pathogens. The most common virus was respiratory syncytial virus (RSV) (32.3%), followed by human rhinovirus (HRV) (30.8%). In HRV-positive patients, eosinophil count was higher than that in Influenza A/B- and Human metapneumovirus-positive patients (respectively p=0.014, 0.005). In RSV-positive patients, hospitalization duration and neutrophil, lymphocyte, C-reactive protein level had moderate correlation (respectively; r=0.587; p=0.005, r=-0.436; p=0.038, r=0.498; p=0.022). Conclusion: Despite the limited number of participants from a single center, a wide range of causative pathogens were detected in our study. In addition, we found that viral pathogens are common etiologies of LRTIs. To describe the disease etiology in LRTIs, assays using an RT-MPCR respiratory pathogen panel, would be beneficial to the detection of etiology and treatment.