Childhood Respiratory Illnesses Before and After COVID-19 Pandemic Restrictions

Introduction With the COVID-19 pandemic, multiple studies described a significant drop in common respiratory viruses in children with the lockdown and restrictions. With the lifting of pandemic precautions, we had the ability to observe new patterns of respiratory illnesses in children and emergency department visits. Materials and methods We studied all respiratory nucleic acid amplification test results in emergency patients from a large metropolitan children's hospital from the years 2018 to 2023. The test included adenovirus, coronaviruses HKU1, NL63, 229E, OC43, metapneumovirus, rhinovirus or enterovirus, influenza A and B, parainfluenza virus types 1-4, respiratory syncytial virus, <i>Bordetella pertussis</i>, <i>Bordetella parapertussis</i>, <i>Chlamydophila pneumoniae</i>, and <i>Mycoplasma pneumoniae</i>. Coronavirus SARS CoV-2 became part of the respiratory panel in November of 2020. We reviewed pediatric emergency department census data to describe the trends before, during, and after COVID-19 pandemic restrictions. Results and conclusions Prior to 2020, there was a median of 1080 tests performed per week with an average positivity rate of 3.7-4.1%. During 2020, this dropped to 486 tests per week with a positivity rate of 1.74%. In 2021, after schools reopened, the median number of tests was 589 per week, with a positivity rate of 4.07%. After schools reopened without masks, the median tests per week were 817, with a positivity rate of 4.71%. Emergency department census data showed a large rebound in 2021 and 2022, with significantly earlier census peaks in these years. Common pediatric respiratory illnesses had an early seasonal spike in the years after the restrictions were lifted, with the most significant being the year in which local schools stopped wearing masks.