viral etiologies of pneumonia and bronchiolitis in hospitalized children during the covid-19 pandemic

Background: viral agents are the most common pathogens that can infect children between the ages of two and five. although previous studies worldwide have investigated the viral causes of lower respiratory infections before the pandemic, researchers focused on the coronavirus with the increase in respiratory infections during the pandemic. however, it became evident that other viruses should also be monitored. objectives: we aimed to detect viruses in cases of pneumonia and bronchiolitis in children over 2 months old during the covid-19 emergency in mashhad. methods: all hospitalized children admitted to akbar hospital, mashhad, iran, from january 2021 to january 2022, with a final evidence-based diagnosis of pneumonia or bronchiolitis by an expert pediatrician were included. convenient nasopharyngeal samples were taken and analyzed with multiplex polymerase chain reaction (pcr). moreover, patients’ on-admission presentations were recorded. data were reported using descriptive statistics and analyzed with ibm spss software. results: we assessed 102 children with an average age of 3.80 ± 3.40 years who were admitted with pneumonia (n = 97) and bronchiolitis (n = 5). covid-19 and respiratory syncytial virus (rsv) were the most frequent viruses in pneumonia and bronchiolitis patients, respectively. the most common symptom was cough, occurring in over 90% of the study population. wheezing was heard in 4 out of 5 bronchiolitis cases, while crackles were more frequent in pneumonia patients (36.1%). the pulse and respiratory rates of children with bronchiolitis were significantly higher than those with pneumonia (p < 0.05). results showed that monocyte counts were significantly different between the groups, with higher counts in bronchiolitis patients. conclusions: the study provided valuable insights into the clinical and laboratory characteristics of pneumonia and bronchiolitis in children, including viral etiology, symptoms, clinical signs, vital signs, and laboratory findings. these findings can aid healthcare professionals in diagnosing and managing these common respiratory infections in hospitalized children. notably, more accurate follow-up is suggested, especially for viral coinfections that might cause higher rates of morbidity and mortality in children. the study provided valuable insights into the clinical and laboratory characteristics of pneumonia and bronchiolitis in children, including viral etiology, symptoms, clinical signs, vital signs, and laboratory findings. these findings can aid healthcare professionals in diagnosing and managing these common respiratory infections in hospitalized children. notably, more accurate follow-up is suggested, especially for viral coinfections that might cause higher rates of morbidity and mortality in children.