Respiratory syncytial virus (RSV) represents the most common cause of acute respiratory hospitalization in children <24 months of age. Several clinical scores have been proposed to estimate disease severity.

This study aims to compare the sensitivity and specificity of clinical scores assessing the severity of bronchiolitis in children <2 years old.

PubMed, Scopus and Web of Science databases were approached to identify all studies published before 31st December 2024 using bronchiolitis severity scores and providing data regarding their sensitivity and specificity.

At the end of the selection process, 18 studies evaluating 13 clinical severity scores were analysed. A total of 6552 children (weighted mean age 5.1 months - range 0-24 months) with a diagnosis of bronchiolitis were included. The summary ROC analysis demonstrated that the GRSS (Global Respiratory Severity Scale) performed better than other scores in discriminating children at risk for severe disease. In particular, the GRSS showed cumulative sensitivity and specificity values of 0.87 (95 %CI: 0.80-0.92) and 0.92 (95 %CI: 0.88-0.95) respectively, with elevated accuracy (0.90).

We limited our analysis only to studies reporting specificity and sensitivity values, possibly excluding other validated scores, but we aimed to perform a balanced analysis involving the most possible homogenous population.

There is limited but moderate-to-adequate evidence that the GRSS score has better sensitivity and specificity for clinically assessing the severity of bronchiolitis in infants and children <2 years old. However, further studies are needed to validate these results, ideally using larger datasets.

Respiratory viral infections present significant global health challenges, causing substantial morbidity and mortality, particularly among highly susceptible components of the population. The emergence of pandemics and epidemics, such as those caused by influenza viruses and coronaviruses, emphasizes the urgent need for effective antiviral therapeutics. In this review, we explore the potential of broad-spectrum antiviral agents targeting respiratory RNA viruses, including influenza viruses, coronaviruses, respiratory syncytial virus, human metapneumovirus, human parainfluenza viruses, and rhinoviruses. Various broad-spectrum direct-acting and host-targeting antivirals are discussed, including monoclonal antibodies targeting conserved regions of viral surface proteins, molecules interfering with host cell receptors or viral replication machinery, viral protease inhibitors, siRNA therapies, ribonuclease, and 3D8 scFv. Advancements in host-targeting approaches to reduce resistance and RNA-based therapeutics offer significant potential for combating respiratory viral threats. Despite challenges, broad-spectrum antiviral agents represent a crucial strategy, particularly when specific viral pathogens are unidentified or rapid intervention is essential, such as during pandemics or outbreaks.

The purpose of this study to compare the effectiveness of the Bronchiolitis Severity Score (BSS) and the Respiratory Distress Assessment Instrument (RDAI) in determining bronchiolitis severity and predicting outcomes. Additionally, it aimed to establish optimum cutoff points for both scores. In this prospective observational study, clinical details of enrolled infants, along with assessments using both scoring tools, were recorded. The performance of these scores in predicting "severe disease," defined by respiratory support requirements other than nasal prongs, PICU admission, respiratory acidosis, and/or altered consciousness, was evaluated. A total of 64 infants diagnosed with bronchiolitis were enrolled with a median age of 5 (3.8) months, and 16 (25%) infants had severe disease. BSS showed 25% sensitivity and 97.9% specificity at established cutoffs of > 8 for severe bronchiolitis. BSS performed better than RDAI in differentiating severe bronchiolitis [AUC, 0.733 vs 0.605; p = 0.035]. New cutoffs of > 5 points for BSS and > 8 points for RDAI increased BSS sensitivity to 68.8% and RDAI sensitivity to 56.3%.

BSS demonstrated superior discriminative ability compared to RDAI in identifying severe bronchiolitis. New cutoff points enhanced BSS's ability to classify severe cases while establishing a cutoff for RDAI. Additional studies are required to validate these revised cutoffs.

• Bronchiolitis severity score (BSS) and Respiratory Distress Assessment Instrument (RDAI) helps in determining bronchiolitis severity.

• BSS has superior discriminatory ability as compared to RDAI in determining bronchiolitis severity. • This study also highlights that neither BSS nor RDAI is perfect, emphasizing the importance of clinical judgment over scoring systems.

The burden of respiratory syncytial virus (RSV) disease is widely recognized. Main risk factors for severe disease, such as extreme ages, chronic cardiopulmonary conditions, and immunosuppression, typically coincide with poorer outcomes. While the majority of RSV hospitalizations involve healthy children, a higher proportion of hospitalized adults with underlying conditions need intensive care. Presently, treatment primarily consists of supportive measures. RSV-induced wheezing should be distinguished from respiratory tract thickening, without response to bronchodilators. Obstructive RSV disease frequently overlaps with viral pneumonia. Non-invasive mechanical ventilation and high-flow oxygen therapy represented significant advancements in the management of severe RSV disease in children and may also hold considerable importance in specific phenotypes of RSV disease in adults. Most severe infections manifest with refractory hypoxemia necessitating more advanced ventilatory support and/or extracorporeal membrane oxygenation therapy. Although bacterial co-infection rates are low, they have been associated with worse outcomes. Antibiotic prescription rates are high. Accurately diagnosing bacterial co-infections remains a challenge. Current evidence and antibiotic stewardship policies advise against indiscriminate antibiotic usage, even in severe cases. The role of currently developing antiviral therapies in severe RSV disease will be elucidated in the coming years, contingent upon the success of new vaccines and immune passive strategies involving nirsevimab.

The global burden of respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) in young children is high. The RSV prevention strategies approved in 2023 will be essential to lowering the global disease burden. In this Series paper, we describe clinical presentation, burden of disease, hospital management, emerging therapies, and targeted prevention focusing on developments and groundbreaking publications for RSV. We conducted a systematic search for literature published in the past 15 years and used a non-systematic approach to analyse the results, prioritising important papers and the most recent reviews per subtopic. Annually, 33 million episodes of RSV LRTI occur in children younger than 5 years, resulting in 3·6 million hospitalisations and 118 200 deaths. RSV LRTI is a clinical diagnosis but a clinical case definition and universal clinical tool to predict severe disease are non-existent. The advent of molecular point-of-care testing allows rapid and accurate confirmation of RSV infection and could reduce antibiotic use. There is no evidence-based treatment of RSV, only supportive care. Despite widespread use, evidence for high-flow nasal cannula (HFNC) therapy is insufficient and increased paediatric intensive care admissions and intubation indicate the need to remove HFNC therapy from standard care. RSV is now a vaccine-preventable disease in young children with a market-approved long-acting monoclonal antibody and a maternal vaccine targeting the RSV prefusion protein. To have a high impact on life-threatening RSV infection, infants at high risk, especially in low-income and middle-income countries, should be prioritised as an interim strategy towards universal immunisation. The implementation of RSV preventive strategies will clarify the full burden of RSV infection. Vaccine probe studies can address existing knowledge gaps including the effect of RSV prevention on transmission dynamics, antibiotic misuse, the respiratory microbiome composition, and long-term sequalae.

Respiratory viruses are increasingly detected in children with community-acquired pneumonia. Further strategies to limit antibiotic use in children with viral pneumonia are warranted.

To explore clinical efficacy of budesonide/formoterol inhalation powder for viral pneumonia in children and its impact on cellular immunity and inflammatory factor production.

A total of 60 children with viral pneumonia were recruited: 30 receiving budesonide/formoterol inhalation powder and 30 conventional symptomatic treatment. Outcome measures included peripheral blood levels of inflammatory cytokines, CD4+, CD8+, Th1, Th2, Th17 and Treg, clinical efficacy, and incidence of adverse reactions.

Compared with the control group, the observation group showed a significant reduction in interleukin-6 and high-sensitivity C-reactive protein levels after treatment. Compared with the control group, the observation group showed a significant increase in CD4+/CD8+ and Th1/Th2 levels, and a decrease in Th17/Treg levels after treatment. The total effective rates in the observation group and the control group were 93.75% and 85.00%, respectively, which was a significant difference (P = 0.003).

Budesonide/formoterol inhalation powder significantly improved therapeutic efficacy for viral pneumonia in children. The mechanism of action may be related to downregulation of the inflammatory response and improved cellular immune function.

Large seasonal outbreaks of bronchiolitis put pressure on healthcare systems and particularly on intensive care units (ICUs). ICU admission is necessary to provide respiratory support to the severest cases, otherwise bronchiolitis can result in substantial mortality. ICU resources are often insufficient and there is scant evidence to guide the ICU clinical management. Most available studies do not cover the ICU-admitted cases and do not consider the associated public health issues. We review this topic through a multidisciplinary approach from both the clinical and public health perspectives, with an analysis based on pathophysiology and cost-effectiveness. We suggest ways to optimise respiratory care, minimise ICU stay, "protect" ICU beds and, whenever possible, make them available for other critically ill children. We also provide guidance on how to prepare ICUs to work under stressful conditions due to outbreaks and to reduce the risk of nosocomial cross-contamination, particularly in ICUs caring for high-risk children.

None.