COVID-19 Pandemic-Related Reductions in Pediatric Asthma Exacerbations Corresponded With an Overall Decrease in Respiratory Viral Infections

PURPOSE OF THE STUDY: Respiratory viruses, air pollutants, and aeroallergens are all implicated as triggers for pediatric asthma symptoms. The current study sought to determine whether changes in respiratory viruses, air pollutants, or aeroallergens during the coronavirus disease 2019 (COVID-19) pandemic were associated with decreased asthma exacerbations. In a prior study, the authors found that during the first months following public health interventions to limit the spread of COVID-19, asthma visits and steroid prescriptions decreased by more than 80%, with a corresponding decrease in rhinovirus infections, without noted changes in air pollution. STUDY POPULATION: The authors reviewed asthma patient encounter data from January 1 to December 31 for the years 2015 through 2020 from the Children's Hospital of Philadelphia Care Network, including 48 outpatient primary care and specialty care sites, 4 urgent care sites, 15 community hospitals, and a 557-bed quaternary care center. Demographic data for outpatient, inpatient, and video visits were characterized by patient sex, race, ethnicity, birth year cohort, and payer type. 2020 data for 28 157 patients were compared with 2015 to 2019 data for 88 039 patients. METHODS: Health care utilization and respiratory viral testing data for the period between January 1, 2015 and December 31, 2020 were extracted from the Children's Hospital of Philadelphia Care Network electronic health record. Air pollution data, including particulate pollution, ozone, and nitrogen dioxide, were obtained from US Environmental Protection Agency databases. Tree, grass, weed, and mold aeroallergen data were obtained from a National Allergy Bureau-certified monitoring station. Summary statistics for rates of encounters and asthma-related prescriptions from 2020 were compared with those from 2015 to 2019. Comparisons were made between prelockdown, lockdown, and phased reopening periods for public health measures in Philadelphia and surrounding counties. RESULTS: During the COVID-19 pandemic, weekly positive tests for influenza A, influenza B, RSV, and rhinovirus were lower than 2015 to 2019 historical averages. Air pollution and aeroallergen trends did not substantially change during the COVID-19 pandemic compared with historic and seasonal average data. CONCLUSIONS: Viral respiratory infections are a primary driver of pediatric asthma exacerbations.