@ERSpublications Epidemiological evidence shows that SARS-CoV-2 infection in children is less frequent and severe than adults. Age-related ACE2 receptor expression, lymphocyte count and trained immunity might be the keystone to reveal children's secret. https://bit.ly/2QWpWxK Cite this article as: Cristiani L, Mancino E, Matera L, et al. Will children reveal their secret? The coronavirus dilemma. Eur Respir J 2020; 55: 2000749 [https://doi.

From 9 March to 3 May 2020, lockdown was declared in Italy due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Our aim was to evaluate how the SARS-CoV-2 pandemic and related preventive strategies affected pediatric emergency rooms (ERs) during this period. We performed a retrospective cohort multicenter study, comparing the lockdown period to the corresponding period in 2019. We examined 15 Italian pediatric ERs in terms of visit rates, specific diagnoses (grouped as air communicable diseases and non-air communicable diseases), and triage categories. During the lockdown period, ER admissions decreased by 81% compared to 2019 (52,364 vs. 10,112). All ER specific diagnoses decreased in 2020 and this reduction was significantly higher for air communicable diseases (25,462 vs. 2934, p < 0.001). Considering the triage category, red codes remained similar (1% vs. 1%), yellow codes increased (11.2% vs. 22.3%), and green codes decreased (80.3% vs. 69.5%). We can speculate that social distancing and simple hygiene measures drastically reduced the spread of air communicable diseases. The increase in yellow codes may have been related to a delay in primary care and, consequently, in ER admissions.

Background Bronchiolitis is the most common acute viral infection of the lower respiratory tract in infants. Clinical severity is associated with different risk factors; however, no clinical, laboratory, or radiological findings are able to predict the course of the disease in full‐term infants. Lung ultrasound (LUS) is a valid technique for the diagnosis and evaluation of pediatric respiratory diseases. Aims The aim of our study was to correlate an LUS score with a clinical score, to describe lung ultrasound findings in cases and controls, and to compare LUS findings with chest X‐ray (CXR) in infants hospitalized with bronchiolitis. Methods We conducted a single‐center, longitudinal, prospective study on 92 infants. Sixty‐three out of 92 infants were hospitalized for acute bronchiolitis (cases) and twenty‐nine out of 92 for diseases not involving the respiratory system (controls). All patients with bronchiolitis underwent a clinical evaluation with the assignment of a clinical severity score and performed lung ultrasound with the assignment of an LUS score. Twenty‐three out of 63 infants with bronchiolitis underwent also a CXR for clinical indications. Control infants performed only LUS. Results In infants with bronchiolitis LUS score showed a positive correlation with the clinical score (r = .62, p < .001) and the length of hospitalization (r = .42; p < .001). The need of oxygen therapy was more frequent in the patients with higher LUS score (p < .001). LUS findings observed in the cases were the presence of B‐lines, subpleural consolidations, and abnormalities of the pleural line. No LUS alterations were observed in the controls. In patients who performed LUS and CXR, we found a correlation between the presence of abnormalities of the pleural line with LUS and the presence of air trapping with CXR (r = .55; p = .007).

Since the beginning of 2020, a remarkably low incidence of respiratory virus hospitalizations has been reported worldwide. We prospectively evaluated 587 children, aged &lt;12 years, admitted for respiratory tract infections from 1 September 2021 to 15 March 2022 in four Italian pediatric hospitals to assess the burden of respiratory viruses during the COVID-19 pandemic in Italy. At admission, a Clinical Respiratory Score was assigned and nasopharyngeal or nasal washing samples were collected and tested for respiratory viruses. Total admissions increased from the second half of October 2021 to the first half of December 2021 with a peak in early November 2021. The respiratory syncytial virus (RSV) incidence curve coincided with the total hospitalizations curve, occurred earlier than in the pre-pandemic years, and showed an opposite trend with respect to the incidence rate of SARS-CoV-2. Our results demonstrated an early peak in pediatric hospitalizations for RSV. SARS-CoV-2 may exhibit a competitive pressure on other respiratory viruses, most notably RSV.

Aim Emergency room admissions have decreased globally during the COVID‐19 pandemic, particularly for respiratory diseases. We evaluated hospital admissions for respiratory diseases in the first year of the Italian pandemic and compared them with the corresponding period in 2016–2017. Methods The study was carried out at the Sapienza University in Rome, Italy, and covered 9 March to 28 February 2020–2021 and 2016–2017. We tested 85 hospitalised children who were negative for the virus that causes COVID‐19 in 2020–2021 and compared them with 476 hospitalised children from 2016–2017, as we had also tested nasal washing samples for 14 respiratory viruses during that period. Results Hospitalisations for acute respiratory tract infections were 82.2% lower in 2020–2021 than 2016–2017. The respiratory syncytial virus (RSV) and several other viruses were detected less frequently during the pandemic. An extraordinary finding was that rhinoviruses remained seasonal. In 2020–2021, we detected a virus in 54.1% of the hospitalised children: rhinoviruses in 41, RSV in 4 and other viruses in 1. This was significantly lower than the 71.6% in 2016–2017: RSV in 130, rhinoviruses in 128 and other viruses in 83. Conclusion Pandemic measures dramatically reduced childhood respiratory infections, particularly RSV, but were less effective at reducing rhinoviruses.