Clinical features of COVID-19 in Italian outpatient children and adolescents during Parental, Delta, and Omicron waves: a prospective, observational, cohort study

Costanza Di Chiara; Riccardo Boracchini; Giulia Sturniolo; Alessia Barbieri; Paola Costenaro; Sandra Cozzani; Marica De Pieri; Cecilia Liberati; Annachiara Zin; Andrea Padoan; Francesco Bonfante; Fatima Kakkar; Anna Cantarutti; Daniele Donà; Carlo Giaquinto

doi:10.3389/fped.2023.1193857

Clinical features of COVID-19 in Italian outpatient children and adolescents during Parental, Delta, and Omicron waves: a prospective, observational, cohort study

Front Pediatr. 2023 Aug 10:11:1193857. doi: 10.3389/fped.2023.1193857. eCollection 2023.

Authors

Costanza Di Chiara^{1

2}, Riccardo Boracchini³, Giulia Sturniolo¹, Alessia Barbieri¹, Paola Costenaro¹, Sandra Cozzani¹, Marica De Pieri¹, Cecilia Liberati¹, Annachiara Zin¹, Andrea Padoan⁴, Francesco Bonfante⁵, Fatima Kakkar⁶, Anna Cantarutti³, Daniele Donà^{1

2}, Carlo Giaquinto^{1

2}

Affiliations

¹ Division of Pediatric Infectious Diseases, Department for Women's and Children's Health, University of Padua, Padua, Italy.
² Penta - Child Health Research, Padua, Italy.
³ Division of Biostatistics, Epidemiology and Public Health, Laboratory of Healthcare Research and Pharmacoepidemiology, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy.
⁴ Department of Medicine-DIMED, University of Padua, Padua, Italy.
⁵ Division of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Padua, Italy.
⁶ Division of Infectious Diseases, Department of Pediatrics, CHU Sainte-Justine, Montréal, QC, Canada.

Abstract

Introduction: COVID-19 features changed with the Omicron variant of SARS-CoV-2 in adults. This study aims to describe COVID-19 symptoms in children and adolescents during the Parental, Delta, and Omicron eras.

Methods: A single-centre, prospective observational study was conducted on individuals aged 0-20 years attending the University Hospital of Padua (Italy) from April 2020 to December 2022. COVID-19 cases were defined by positive SARS-CoV-2 molecular detection and/or serology; patient/family symptoms and virological positivity were considered to determine the infection onset. Variables were summarized and compared using appropriate tests of descriptive statistics.

Results: A total of 509 cases [46% female, median age eight years (IQR: 4-12)] were studied. Three-hundred-eighty-seven (76%), 52 (10%), and 70 (14%) subjects experienced COVID-19 during the Parental, Delta, and Omicron waves, respectively. All subjects developed an asymptomatic/mild COVID-19. Overall, the most frequent symptoms were fever (47%) and rhinitis (21%), which showed a significant increasing incidence from the Parental to Omicron waves (p < 0.001). Conversely, diarrhea was most common during the pre-Omicron eras (p = 0.03). Stratifying symptoms according to the age group, fever, rhinitis, and skin rashes were observed more frequently among infants/toddlers; conversely, fatigue was more common in children older than five years. The duration of symptoms was similar across different SARS-CoV-2 variants of concern (VOCs); conversely, the number of symptoms varied according to the age group (p < 0.0001).

Discussion: This study showed differences in COVID-19 clinical presentation among infants, children, and adolescents and confirmed Omicron infection is more likely to be associated with upper respiratory symptoms. However, further population-based studies are needed to support these findings. In addition, active surveillance will play a crucial role in assessing the disease severity of future VOCs.

Keywords: COVID-19; SARS-CoV-2; children; clinical manifestations; pediatric population; symptoms; variants of concern.

Grants and funding

This work is part of the VERDI project (grant no. 101045989), which is funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Health and Digital Executive Agency. Neither the European Union nor the granting authority can be held responsible for them.