Patients.
The Epidemiological Study of Coronavirus in Children (EPICO-AEP) is a prospective multicenter national study conducted in Spain to assess the characteristics of children with COVID-19. In the present study, we included hospitalized children with a primary diagnosis of SARS-CoV-2-associated pneumonia enrolled in EPICO-AEP. CAP was defined as fever or respiratory symptoms and an image consistent with pneumonia in the chest x-ray, according to the criteria applied by the attending physician. COVID-19 infection was confirmed by RT-PCR testing or by rapid antigen detection testing on nasopharyngeal swabs. We enrolled pediatric patients (ages 18 years and younger) from 80 hospitals of the network, from February 25th, 2020 to April 30th, 2021.
Epidemiological, clinical, laboratory and radiological data were collected from medical records, including the age at onset of the infection, sex, clinical signs and symptoms, outcomes, laboratory data, chest X‐ray findings, comorbidities, treatment, and pediatric intensive care unit (PICU) admission. Radiographs were obtained following the institutional protocols of each participating center, and all included patients underwent at least one chest X-ray. We used a standardized data collection online platform (Research Electronic Data Capture: RedCAPTM) to record and collect the clinical data.
The findings were compared with data from children diagnosed with viral-associated CAP from a different study performed by our group11. In this study, eligible participants were children under 18 years of age admitted to any of the participating hospitals, with radiologically-confirmed CAP, from April 2012 to May 2019. An extensive microbiological workup was performed, including blood cultures, Streptococcus pneumoniae antigen (BinaxNowTM) and/or RT-PCR for S.pneumoniae in pleural fluid if thoracentesis was performed, RT-PCR in blood forS.pneumoniae , multiplex RT-PCR on nasopharyngeal aspirate samples for pertussis and for the following panel of 16 viruses: RSV, hMPV, PIV 1, 2, 3 and 4, influenza (A and B), human bocavirus (hBoV), ADV, enterovirus (EV), RhV, and coronavirus (CoV) 229E, OC43, NL63 and HKU12. Two paired samples for serology (at admission and 2–4 weeks later) forMycoplasma pneumoniae and Chlamydia pneumoniae were performed using enzyme-linked immunoassays 12.
Viral etiology was assigned to CAP if at least one putative pathogen respiratory virus (RSV, influenza A or B, PIV, hMPV) was detected in nasopharyngeal aspirates by PCR, and no bacterial pathogen was detected. Other respiratory viruses (RhV, ADV, EV, CoV, hBoV) were not included as likely viral infections due to poor specificity for CAP13,14.
Both studies were approved by the ethics committee of every center, and all guardians signed the informed consent to participate in the study.