Introduction
Following the opening of lockdown and relaxation of public health restrictions, an unusual surge of respiratory illness occurred during the spring/summer (Q2) 2021 season. We aimed to characterize this surge compared to previous years.
Methods
Children discharged from a single tertiary hospital for respiratory illness or selected noncommunicable diseases (NCDs) between 2015 and 2021 were included, and hospitalization rates were compared. To evaluate whether the current respiratory surge resembles a typical winter, characteristics of the second quarter (Q2, April–June) of 2021 were compared to parallel seasons and to autumn/winter (Q4, October–December) of the previous years.
Results
Respiratory illness showed a seasonal peak, while the pattern of NCD was consistent throughout the study period. Respiratory illnesses showed a delayed surge in Q2 2021 (389 patients), with a missing seasonal peak in Q2 and Q4 2020 (135 and 119 patients, respectively). There were more cases of croup in Q2 2021 compared to Q2 and Q4 2015–2019 (26.2 vs. 12.5% and 15.8%, p < 0.001), fewer cases of pneumonia (5.9 vs. 15.9% and 11.7%, p < 0.001), lower admission rates (22.4 vs. 36.3% and 31.5%, p < 0.001), and fewer hypoxemia during hospitalization (6.3 vs. 11.7% and 10%, p < 0.001). Additionally, lower use of antibiotics (6.2 vs. 12.3% and 10.3%, p = 0.001 and 0.012, respectively) and higher use of steroids (33.7 vs. 24.8% and 28.3%, p < 0.001 and 0.034, respectively).
Conclusions
The postponed increase in respiratory morbidity after lockdown had unique characteristics, with upper respiratory illness predominating and fewer hospitalizations. Follow‐up is needed to assess the altered epidemiological patterns of respiratory diseases in the post‐COVID era.