Respiratory Syncytial Virus Severity Research Articles

Update to: Study Pre-protocol for "BronchStart - The Impact of the COVID-19 Pandemic on the Timing, Age and Severity of Respiratory Syncytial Virus (RSV) Emergency Presentations; a Multi-Centre Prospective Observational Cohort Study".

In 2021 we launched the BronchStart study, which collected information on 17,899 presentations in children with serious respiratory tract infections following the release of lockdown restrictions. Our study informed the Joint Committee on Vaccination and Immunisation's decision to recommend the introduction maternal respiratory syncytial virus (RSV) vaccination, which was introduced in the United Kingdom in August/September 2024. We modified our original protocol to conduct a United Kingdom-wide assessment of maternal vaccination against RSV. We will conduct a multi-centre study, utilising the PERUKI network used in the original BronchStart study, to assess the effectiveness of maternal vaccination using a test-negative study design. We will gather detailed clinical information on children admitted with bronchiolitis in the post-RSV vaccination era, and understand possible reasons for incomplete vaccine uptake.

Severity of respiratory syncytial virus compared with SARS-CoV-2 and influenza among hospitalised adults ≥65 years

Our aim was to estimate the risk of pneumonia, admission to intensive care unit (ICU) or death in individuals ≥65 years old admitted to hospital with RSV, compared to influenza or COVID-19. We included hospitalised patients from Severe Acute Respiratory Infection Surveillance in Spain between 2021-2024, aged ≥65 years, laboratory confirmed for RSV, influenza or SARS-CoV-2. Using a binomial regression with logarithmic link, we estimated the relative risk (RR) of pneumonia, ICU admission and in-hospital mortality, in patients with RSV compared to influenza or SARS-CoV-2, adjusting for age, sex, season and comorbidities. We stratified the estimates by vaccination status for influenza or SARS-CoV2. Among patients unvaccinated for influenza or SARS-CoV-2, those with RSV had similar or lower risk of pneumonia [vs. influenza: RR=0.91 (95% Confidence Interval: 0.72-1.16); vs. SARS-CoV-2: 0.81 (0.67-0.98)], ICU admission [vs. influenza: 0.93 (0.41-2.08); vs. SARS-CoV-2: 1.10 (0.61-1.99)] and mortality [vs. influenza: 0.64 (0.32-1.28); vs. SARS-CoV-2: 0.56 (0.30-1.04)]. Among the vaccinated, results were largely similar except for a higher risk of ICU admission with RSV [vs. influenza: 2.13(1.16-3.89); vs. SARS-CoV-2: 1.83 (1.02-3.28)] CONCLUSIONS: RSV presented similar or lower intrinsic severity than influenza or SARS-CoV2. Among vaccinated patients, RSV was associated to higher ICU-admission, suggesting the potential for preventive RSV vaccination.

Association of SNP-SNP interactions of surfactant protein genes with severity of respiratory syncytial virus infection in children.

The severity of respiratory syncytial virus (RSV) may be linked to host genetic susceptibility. Surfactant protein (SP) genetic variants have been associated with RSV severity, but the impact of single-nucleotide polymorphism (SNP)-SNP interactions remains unexplored. Therefore, we used a novel statistical model to investigate the association of SNP-SNP interactions of SFTP genes with RSV severity in two- and three-interaction models. We analyzed available genotype and clinical data from prospectively enrolled 405 children diagnosed with RSV, categorizing them into moderate or severe RSV groups. Using Wang's statistical model, we studied significant associations of SNP-SNP interactions with RSV severity in a case-control design. We observed, first, association of three interactions with increased risk of severe RSV in a two-SNP model. One intragenic interaction was between SNPs of SFTPA2, and the other two were intergenic, involving SNPs of hydrophilic and hydrophobic SPs alone. We also observed, second, association of 22 interactions with RSV severity in a three-SNP model. Among these, 20 were unique, with 12 and 10 interactions associated with increased or decreased risk of RSV severity, respectively, and included at least one SNP of either SFTPA1 or SFTPA2. All interactions were intergenic except one, among SNPs of SFTPA1. The remaining interactions were either among SNPs of hydrophilic SPs alone (n = 8) or among SNPs of both hydrophilic or hydrophobic SPs (n = 11). Our findings indicate that SNPs of all SFTPs may contribute to genetic susceptibility to RSV severity. However, the predominant involvement of SFTPA1 and/or SFTPA2 SNPs in these interactions underscores their significance in RSV severity.NEW & NOTEWORTHY Although surfactant protein (SP) genetic variants are associated with respiratory syncytial virus (RSV) severity, the impact of single-nucleotide polymorphism (SNP)-SNP interactions of SP genes remained unexplored. Using advanced statistical models, we uncovered 22 SNP-SNP interactions associated with RSV severity, with notable involvement of SFTPA1 and SFTPA2 SNPs. This highlights the comprehensive role of all SPs in genetic susceptibility to RSV severity, shedding light on potential avenues for targeted interventions.

Seasonality and severity of respiratory syncytial virus during the COVID-19 pandemic: a dynamic cohort study

ObjectivesTo investigate seasonality, epidemiologic characteristics, and clinical severity variations of respiratory syncytial virus (RSV)-associated hospitalizations following the easing of COVID-19 restrictions in Tuscany, Italy, up to the 2022-2023 season. MethodsFrom 2017 to 2023, a dynamic cohort consisting of all resident children aged ≤2 years was followed up in regional registries. The person-time incidence rate of RSV-associated hospitalizations per 1,000 person-years and risk of severe hospitalization (intensive care unit, continuous positive airway pressure, or mechanical ventilation) per 100 RSV hospitalizations were calculated. RSV seasonality was investigated with retrospective methods. ResultsA total of 193,244 children were followed up. After the easing of restrictions, RSV epidemics showed earlier seasonality and shorter duration compared with pre-pandemic (2017 to 2019), with this deviation decreased in 2022-2023. In 2021-2022 and 2022-2023, the incidence rate of RSV-associated hospitalizations significantly increased compared with pre-pandemic (2022-2023 risk ratio 3.6, 95% confidence interval 3.3-4.0), with larger increases among older age groups. Among hospitalized children, only those aged ≥12 months showed an increased risk of severe hospitalization, particularly during 2021-2022 (risk ratio 4.7, 95% confidence interval 1.5-24.3). ConclusionsOur findings suggest a gradual return of RSV epidemics to the pre-pandemic pattern, although relevant increases in disease incidence persist. Reduced regular RSV exposure among older children may lead to declining immunity and increased severe outcome risks.

Does weight influence the course of RSV bronchiolitis in hospitalized infants?

Acute bronchiolitis is among the most common causes of hospitalizations in infants worldwide. Associations between weight and severity of respiratory syncytial virus (RSV) bronchiolitis remain unclear. The aim of this study was to evaluate this association. A single-center, retrospective cohort study of infants aged under 24 months, who were hospitalized between 2018 and 2022 for RSV bronchiolitis. Data from computerized medical records were extracted using the MDclone platform. Participants were divided into three groups according to weight percentiles: underweight (below 5th percentile), normal-weight, and overweight (above 85th percentile). A total of 1936 infants (mean age 6.3 months, 55% males) were included, comprising 274 infants who were underweight, 1470 with normal weight, and 192 with overweight. Underweight infants had a higher rate of admission to the pediatric intensive care unit (PICU) (9.1% vs. 3.5%, P < 0.005) and prolonged length of stay (LOS) in the hospital (3.13 vs. 2.79 days P < 0.001) compared to those with normal weight. Hyponatremia was also more common in the underweight group (23% vs. 15%, P < 0.001). A multivariable model accounting for prematurity and birthweight predicted a relative risk of 2.01 (95% CI 1.13-3.48, P = 0.015) for PICU admission and 1.42 (95% CI 1.17-1.7, P < 0.001) for a prolonged LOS. Being overweight was not associated with a more severe disease. Conclusion: Underweight infants, hospitalized for RSV bronchiolitis, had a more severe disease course with a higher complication rate, including PICU admission and prolonged LOS. Thus, careful attention and supervision should be given to this subgroup of infants. What is Known: • Established risk factors for severe bronchiolitis include prematurity, BPD, CHD, and compromised immunity. • Abnormal weight status has been associated with an increased risk for morbidity and mortality from infectious diseases, proposedly due to the effects on endocrine and immunologic systems. What is New: • Underweight infants hospitalized with RSV bronchiolitis face an independent risk of PICU admission and prolonged hospital stay. • Conversely, overweight infants did not display associations with severity measures in our study.

Respiratory syncytial virus subtypes in children with bronchiolitis: does it correlate with clinical severity?

BackgroundIn this retrospective study, we aimed to evaluate the factors associated with the severity of respiratory syncytial virus (RSV) bronchiolitis in children aged under 2 years who were admitted to the Children’s Hospital of Hebei between June 2018 and January 2019.MethodsSputum samples positive for RSV via multiplex PCR were subtyped using real-time PCR. Data collected included risk factors for disease severity, demographics, microbiology, and outcomes.ResultsOf the 82 children with RSV bronchiolitis, 79 were treated and discharged with improvement, while 3 died. All three patients had underlying medical conditions, including complex congenital heart disease and severe combined immunodeficiency. Further, disease severity was associated with preexisting underlying disease, fever duration, and bacterial co-infection, but not with the RSV subtype.ConclusionsOur findings suggest that an appropriate therapeutic regimen should include the detection of bacterial co-infections and the identification of underlying diseases for the effective management of severe RSV bronchiolitis.

Study on transcriptome characteristics of respiratory syncytial virus bronchiolitis in children by RNA sequencing

To explore the biological characteristics related to the pathogenesis and severity of respiratory syncytial virus (RSV) bronchiolitis by RNA sequencing of white blood cells in children with RSV bronchiolitis. This study is a case-control study. A total of 87 children diagnosed with bronchiolitis and RSV antigen positive and/or RSV nucleic acid positive in the pediatric respiratory department of the Second Affiliated Hospital of Wenzhou Medical University from October 2019 to April 2022 were selected as the case group. The case group was divided into three groups based on the condition: mild, moderate, and severe, and there were two groups according to the presence or absence of atopic symptoms: the atopic group and the non-atopic group, forty healthy children in the same period were selected as the control group. The whole blood leukocyte RNA of the children in the case group and the control group was extracted for RNA sequencing, and the data were analyzed to obtain differentially expressed genes (DEGs). Then, the immunobiological pathways and genes related to the pathogenesis, disease condition, and atopy were screened through Gene Ontology (GO) annotation, Kyoto Gene and Genome Encyclopedia (KEGG) annotation, and protein interaction network (PPI) construction methods. Construct the weighted gene co-expression network analysis (WGCNA) module to identify potential biological indicators related to disease severity.Compared with the control group, the case group had a total of 1 782 DEGs, including 1 586 upregulated genes and 196 downregulated genes. The GO pathway enrichment of DEGs is mainly enriched in molecular functions such as peroxidase activity and oxidoreductase activity. In the cytological components, it is mainly enriched in cytoplasmic vesicle lumen and secretory granule lumen. In biological processes, it is mainly enriched in processes such as neutrophil activation involved in immune responses, neutrophil degranulation, and neutrophil activation. KEGG analysis is mainly concentrated in the signal pathway of the viral protein interaction with cytokine and cytokine receptor. A PPI network was constructed to screen four genes at the core position, including CCL2, IL-10, MMP9 and JUN. The DEGs obtained by comparing different disease groups with the control group are mainly enriched in retrograde endocannabinoid signaling and cell apoptosis pathways. WGCNA analysis showed that the brown module related to oxygen saturation was most closely related to the disease, and its gene was mainly enriched in the RNA helicase retinoic acid inducible gene-I (RIG-I) like receptor signal pathway. There are 230 specific DEGs in the atopic group and 444 in the non-atopic group. KEGG enrichment analysis results show that both groups are enriched to NF-κB signaling pathway, the characteristic does not cause significant changes in immune response and transcriptome characteristics in children with RSV bronchiolitis. In conclusion, neutrophil activation, degranulation pathway and signal pathway of interaction between viral protein and cytokine and cytokine receptor are involved in the immune response of RSV bronchiolitis host. CCL2, IL-10, MMP9 and JUN genes may be associated with the pathogenesis. They might be potential biomarkers related to disease severity in RIG-I like receptors, cell apoptosis, and endogenous cannabinoid related signaling pathways.

Disease Severity of Respiratory Syncytial Virus Compared with COVID-19 and Influenza Among Hospitalized Adults Aged ≥60 Years - IVY Network, 20 U.S. States, February 2022-May 2023.

On June 21, 2023, CDC's Advisory Committee on Immunization Practices recommended respiratory syncytial virus (RSV) vaccination for adults aged ≥60 years, offered to individual adults using shared clinical decision-making. Informed use of these vaccines requires an understanding of RSV disease severity. To characterize RSV-associated severity, 5,784 adults aged ≥60 years hospitalized with acute respiratory illness and laboratory-confirmed RSV, SARS-CoV-2, or influenza infection were prospectively enrolled from 25 hospitals in 20 U.S. states during February 1, 2022-May 31, 2023. Multivariable logistic regression was used to compare RSV disease severity with COVID-19 and influenza severity on the basis of the following outcomes: 1) standard flow (<30 L/minute) oxygen therapy, 2) high-flow nasal cannula (HFNC) or noninvasive ventilation (NIV), 3) intensive care unit (ICU) admission, and 4) invasive mechanical ventilation (IMV) or death. Overall, 304 (5.3%) enrolled adults were hospitalized with RSV, 4,734 (81.8%) with COVID-19 and 746 (12.9%) with influenza. Patients hospitalized with RSV were more likely to receive standard flow oxygen, HFNC or NIV, and ICU admission than were those hospitalized with COVID-19 or influenza. Patients hospitalized with RSV were more likely to receive IMV or die compared with patients hospitalized with influenza (adjusted odds ratio=2.08; 95% CI=1.33-3.26). Among hospitalized older adults, RSV was less common, but was associated with more severe disease than COVID-19 or influenza. High disease severity in older adults hospitalized with RSV is important to consider in shared clinical decision-making regarding RSV vaccination.

The epidemiologic trend of respiratory syncytial virus has returned strongly to its origin after the pandemic: Five-year data from a single center.

Only a few studies have investigated the frequency and severity of respiratory syncytial virus (RSV) infections after the end of the pandemic regulations. This study aims to investigate the frequency and severity of RSV infections before, during, and after the pandemic in Turkey. Patients under 18 years of age and those who tested positive for RSV between April 2018 and March 2023 were retrospectively reviewed. All patients were divided into three groups (pre-COVID-19, COVID-19, and post-COVID-19) according to admission date. Among inpatients, data were compared between the three groups to determine the impact of the pandemic on RSV epidemiology and clinical outcomes. A total of 9567 patients were tested for RSV, of which 1073 (11.2%) were positive and included in the study. Hospitalization occurred in 447 (41.7%) patients. Inpatients were younger than outpatients (p < .000). Among the three inpatient pandemic groups, clinical outcomes were statistically significantly worse in the post-COVID-19 group than in the other two groups. SpO2 was lower (p < .000), inhaled salbutamol requirement was higher (p < .000), length of stay was longer (p = .031), and ICU admission was higher (p = .023). Although the RSV trend changed within 2 years after the COVID-19 outbreak, it returned to its usual seasonality last year. After the repeal of all COVID-19 measures and the normal life began, the number of RSV-positive patients and RSV-related hospitalizations increased, and the clinical outcomes of RSV worsened. This may be a result of decreased herd immunity due to a change in society's attitude toward epidemic diseases.

Clinical Relevance of RSV and SARS-CoV-2 Coinfections in Infants and Young Children.

We analyzed the frequency, clinical impact and severity of respiratory syncytial virus (RSV) and SARS-CoV-2 coinfections in a single pediatric center between March 2020 and January 2023. Compared to single RSV infections, RSV/SARS-CoV-2 coinfections were uncommon (2.1%), occurred more frequently during circulation of omicron, and were associated with increased disease severity as defined by longer hospitalization and increased need for high-flow nasal cannula.

Shifting Epidemiology and Severity of Respiratory Syncytial Virus in Children During the COVID-19 Pandemic

This cohort study examined changes in RSV age distribution and disease severity in Colorado children after the COVID-19 pandemic.

Impact of breastfeeding on the incidence and severity of respiratory syncytial virus (RSV)-associated acute lower respiratory infections in infants: a systematic review highlighting the global relevance of primary prevention

BackgroundRespiratory syncytial virus (RSV) is the principal cause of acute lower respiratory infections (ALRI) among infants worldwide, and an important cause of morbidity, hospitalisation and mortality. While infants are universally...

Measuring respiratory syncytial virus infection severity in hospitalized children using the Pediatric Respiratory Syncytial Virus Electronic Severity and Outcome Rating System (PRESORS)

The Pediatric Respiratory Syncytial Virus Electronic Severity and Outcome Rating System (PRESORS) was developed to assess the severity of respiratory syncytial virus (RSV) infection in children. Because young children cannot report how they feel or function, ratings are based on observations by the child's caregiver (Observer-Reported Outcome questionnaire [ObsRO]) and clinician (Clinician-Reported Outcome questionnaire [ClinRO]). This prospective study aimed to evaluate the psychometric properties of the PRESORS. The PRESORS version 6 ObsRO and ClinRO were evaluated in children with RSV infection requiring hospitalization in centers in the United States, Argentina, and Chile. Assessments were performed from days 1 to 7 by the child's caregiver and clinician. To assess inter-rater reliability, two clinicians independently performed the ClinRO near in time. A total of 124 children aged ≤36 months were enrolled (mean age, 8months). Factor analysis demonstrated that RSV severity consists of two dimensions, respiratory signs and illness behavior, and that these dimensions were consistent over time. The inter-rater reliability for the ClinRO was 0.66 (95% confidence interval [CI], 0.55-0.75) but improved to 0.79 (95% CI, 0.71-0.86) after removing one outlying site, suggesting that quantifying RSV severity is not trivial, even using qualified raters, but that an adequate inter-rater reliability is achievable with the PRESORS through adequate training. ClinRO and ObsRO displayed acceptable internal consistency and acceptable convergent validity with the Respiratory Syncytial Virus Network Scale, global impression scores, and key hospital characteristics. The PRESORS is relevant and appropriate for assessing the severity of RSV infection in infants requiring hospitalization.

Clinical severity of RSV bronchiolitis.

BackgroundStudies comparing the severity of respiratory syncytial virus (RSV) bronchiolitis to other viruses are inconclusive. Our study aimed to compare the severity of bronchiolitis according to the virus.MethodsData were collected from 1152 infants under one year of age admitted to Children's hospital for Wales, over the winter months of 2014–2020. The cohort was divided based on the virus detected: RSV, RSV with another virus, or other virus. Using t tests and Fisher exact statistical test, the groups were compared based on length of hospital stay, admissions PICU/HDU, intubations, and need of nasogastric (NG) nutritional support.ResultsFifty‐six percent throat swabs were RSV positive, 15% had RSV with another virus, and 29% had only another virus. Children positive for RSV had statistically longer hospital admissions and were more likely to need NG nutrition; however, there was no difference between number of PICU/HDU admissions or intubations. The RSV group and RSV with another virus group had no statistical differences.

Study Pre-protocol for "BronchStart - The Impact of the COVID-19 Pandemic on the Timing, Age and Severity of Respiratory Syncytial Virus (RSV) Emergency Presentations; a Multi-Centre Prospective Observational Cohort Study".

Background: Bronchiolitis (most frequently caused by respiratory syncytial virus; RSV) is a common winter disease predominantly affecting children under one year of age. It is a common reason for presentations to an emergency department (ED) and frequently results in hospital admission, contributing to paediatric units approaching or exceeding capacity each winter. During the SARS-CoV-2 pandemic, the circulation of RSV was dramatically reduced in the United Kingdom and Ireland. Evidence from the Southern Hemisphere and other European countries suggests that as social distancing restrictions for SARS-CoV-2 are relaxed, RSV infection returns, causing delayed or even summer epidemics, with different age distributions. Study question: The ability to track, anticipate and respond to a surge in RSV cases is critical for planning acute care delivery. There is an urgent need to understand the onset of RSV spread at the earliest opportunity. This will influence service planning, to inform clinicians whether the population at risk is a wider age range than normal, and whether there are changes in disease severity. This information is also needed to inform decision on the timing of passive immunisation of children at higher risk of hospitalisation, intensive care admission or death with RSV infection, which is a public health priority. Methods and likely impact: This multi-centre prospective observational cohort study will use a well-established research network (Paediatric Emergency Research in the UK and Ireland, PERUKI) to report in real time cases of RSV infection in children aged under two years, through the collection of essential, but non-identifying patient information. Forty-five centres will gather initial data on age, index of multiple deprivation quintile, clinical features on presentation, and co-morbidities. Each case will be followed up at seven days to identify treatment, viral diagnosis and outcome. Information be released on a weekly basis and used to support clinical decision making.

Monitoring Severity of Respiratory Syncytial Virus (RSV) in Infants and Young Children Using the Pediatric RSV Electronic Severity and Outcome Rating System (PRESORS): Results of Initial Quantitative Validation.

PurposePRESORS ClinRO completed by clinicians and ObsRO completed by caregivers were developed to characterize the clinical course of respiratory syncytial virus (RSV) infection. This study describes preliminary analysis of PRESORS’ measurement properties using clinical trial data.Patients and MethodsPRESORS ClinRO and ObsRO data were collected in a 28-day randomized, double-blind, Phase 1b trial of JNJ-53718678 or placebo in infants and children ≤24 months of age treated for RSV infection in hospitals. PRESORS data were scored and key psychometric properties of scores were evaluated, including ability to discriminate between known groups and to detect change over time. Time to resolution of RSV signs was explored using two responder definitions.ResultsDaily completion rates for PRESORS ClinRO and ObsRO were high for the 44 children in the study (median: 100% and 93%, respectively). Large floor effects were observed at baseline for signs of severe RSV infection that were either absent (cyanosis, fever, apnea) or rarely reported (reduced urination/dehydration, vomiting). Implausible ObsRO ratings suggested some caregivers could not accurately measure heart rate. Known-group validity was confirmed: children in poor health based on baseline ClinRO had mean baseline composite scores that were significantly worse for both ObsRO (p=0.001) and ClinRO (p<0.001) compared to those with better overall health. ObsRO (p=0.009) and ClinRO (p<0.001) composite scores were responsive to change in overall health status from baseline to Day 3. Mean scores for RSV sign dimensions decreased rapidly from baseline to Day 7 except for coughing and sleep ratings by caregivers. Time to recovery varied greatly depending on definitions used.ConclusionPRESORS ClinRO and ObsRO can inform endpoints and enable monitoring the clinical course of RSV in pediatric trials. Improved alignment between ClinRO and ObsRO and revisions ensuring caregivers can assess all signs will be addressed in revised PRESORS.

Study Pre-protocol for “BronchStart - The Impact of the COVID-19 Pandemic on the Timing, Age and Severity of Respiratory Syncytial Virus (RSV) Emergency Presentations; a Multi-Centre Prospective Observational Cohort Study”

Background: Bronchiolitis (most frequently caused by respiratory syncytial virus; RSV) is a common winter disease predominantly affecting children under one year of age. It is a common reason for presentations to an emergency department (ED) and frequently results in hospital admission, contributing to paediatric units approaching or exceeding capacity each winter. During the SARS-CoV-2 pandemic, the circulation of RSV was dramatically reduced in the United Kingdom and Ireland. Evidence from the Southern Hemisphere and other European countries suggests that as social distancing restrictions for SARS-CoV-2 are relaxed, RSV infection returns, causing delayed or even summer epidemics, with different age distributions. Study question: The ability to track, anticipate and respond to a surge in RSV cases is critical for planning acute care delivery. There is an urgent need to understand the onset of RSV spread at the earliest opportunity. This will influence service planning, to inform clinicians whether the population at risk is a wider age range than normal, and whether there are changes in disease severity. This information is also needed to inform decision on the timing of passive immunisation of children at higher risk of hospitalisation, intensive care admission or death with RSV infection, which is a public health priority. Methods and likely impact: This multi-centre prospective observational cohort study will use a well-established research network (Paediatric Emergency Research in the UK and Ireland, PERUKI) to report in real time cases of RSV infection in children aged under two years, through the collection of essential, but non-identifying patient information. Forty-five centres will gather initial data on age, index of multiple deprivation quintile, clinical features on presentation, and co-morbidities. Each case will be followed up at seven days to identify treatment, viral diagnosis and outcome. Information be released on a weekly basis and used to support clinical decision making.

Study Pre-protocol for "BronchStart - The Impact of the COVID-19 Pandemic on the Timing, Age and Severity of Respiratory Syncytial Virus (RSV) Emergency Presentations; a Multi-Centre Prospective Observational Cohort Study".

Background: Bronchiolitis (most frequently caused by respiratory syncytial virus; RSV) is a common winter disease predominantly affecting children under one year of age. It is a common reason for presentations to an emergency department (ED) and frequently results in hospital admission, contributing to paediatric units approaching or exceeding capacity each winter. During the SARS-CoV-2 pandemic, the circulation of RSV was dramatically reduced in the United Kingdom and Ireland. Evidence from the Southern Hemisphere and other European countries suggests that as social distancing restrictions for SARS-CoV-2 are relaxed, RSV infection returns, causing delayed or even summer epidemics, with different age distributions. Study question: The ability to track, anticipate and respond to a surge in RSV cases is critical for planning acute care delivery. There is an urgent need to understand the onset of RSV spread at the earliest opportunity. This will influence service planning, to inform clinicians whether the population at risk is a wider age range than normal, and whether there are changes in disease severity. This information is also needed to inform decision on the timing of passive immunisation of children at higher risk of hospitalisation, intensive care admission or death with RSV infection, which is a public health priority. Methods and likely impact: This multi-centre prospective observational cohort study will use a well-established research network (Paediatric Emergency Research in the UK and Ireland, PERUKI) to report in real time cases of RSV infection in children aged under two years, through the collection of essential, but non-identifying patient information. Forty-five centres will gather initial data on age, index of multiple deprivation quintile, clinical features on presentation, and co-morbidities. Each case will be followed up at seven days to identify treatment, viral diagnosis and outcome. Information be released on a weekly basis and used to support clinical decision making.

Rapid weight gain in early life is associated with severity of respiratory syncytial virus (RSV) bronchiolitis in children.

This study aimed to investigate whether rapid weight gain in early life was associated with the severity of respiratory syncytial virus (RSV) bronchiolitis in children. We retrospectively reviewed 190 patients (1-24 months) hospitalized for RSV bronchiolitis. Parameters of bronchiolitis severity were compared between rapid (change in weight z-score from birth >0.67, n = 65) and normal weight gain groups (n = 125). We assessed for correlations between bronchiolitis severity and weight gain. Linear regression was performed to predict for bronchiolitis severity based on weight gain, controlling for covariates. SPSS was used for statistical analyses. The rapid weight gain group had longer mean durations of tachypnea (2.3±2.0 vs. 1.7±1.8 days, P = 0.027), wheezing (3.2±2.5 vs. 1.6±1.8 days, P < 0.001), and chest retractions (1.5±2.2 vs. 0.6±1.3 days, P = 0.007). Correlations of weight gain with tachypnea (r = 0.146), wheezing (r = 0.279), and chest retractions (r = 0.179) were statistically significant. Weight gain predicted for tachypnea (B = 0.485, P = 0.013) and wheezing (B = 0.846, P = 0.001) durations after adjusting for covariates of severity (age, sex, current weight, RSV type, coinfection, recurrent bronchiolitis, hospital stay, fever, oxygen supplementation, maximal respiratory and heart rates, and laboratory indices). Our findings suggest an association between weight gain and severity of RSV bronchiolitis in young children. Weight gain was significantly associated with the durations of tachypnea and wheezing. The trajectory of weight gain in early life may play a significant role in the clinical course of RSV bronchiolitis.

Cost of Hospitalization Associated With Respiratory Syncytial Virus Infection Versus Influenza Infection in Hospitalized Older Adults.

Despite the severity of respiratory syncytial virus (RSV) disease in older adults, data on its costs are limited. We compared hospitalization costs for 2090 adults aged ≥ 60 years hospitalized with RSV or influenza by assigning direct health care costs. Hospitalization with RSV was associated with longer hospitalization and increased frequency of diagnosis-related groups for pulmonary complications, resulting in costs at least as great as those for influenza ($16 034 vs $15 163; 95% confidence interval for the difference, -$811 to $2547). Awareness of RSV disease burden in adults is needed to facilitate vaccination and treatment when they become available.