Prospective population-based study of RSV-related intermediate care and intensive care unit admissions in Switzerland over a 4-year period (2001-2005)

Risk Factors and Clinical Prognosis Associated With RSV-ALRI Intensive Care Unit Admission in Children <2 Years of Age: A Multicenter Study

BACKGROUND

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infections (ALRIs) in children <2 years of age. Currently, there are limited data on risk factors for very severe RSV-ALRI requiring intensive care unit (ICU) admission.

METHODS

We conducted a case-control study of children <2 years old admitted with RSV-ALRI to the Sydney Children's Hospital Network, comprising 2 large tertiary pediatric hospitals. Cases were children with laboratory-confirmed RSV-ALRI admitted to ICU, and controls were (1:2, matched on date of admission) children hospitalized with RSV-ALRI but not requiring ICU transfer. Data on risk factors were retrieved from the electronic medical record system. Adjusted odds ratios (aORs) with 95% confidence intervals (95% CI) associated with risk factors for ICU admission and the association with clinical and treatment factors were determined from logistic regression models.

RESULTS

A total of 44 (44%) of 100 cases and 90 (48.1%) of 187 controls were male. Age <6 months and preterm births were associated with a 2.10-fold (95% CI: 1.14-3.79) and 2.35-fold (95% CI: 1.26-4.41) increased risk in ICU admissions, respectively. The presence of any chronic health condition was a significant risk factor for ICU admission. The clinical presentations on admission more commonly seen in cases were apnea (aOR: 5.01, 95% CI: 1.50-17.13) and respiratory distress (aOR: 15.91, 95% CI: 4.52-55.97). Cases were more likely to be hospitalized for longer duration and require respiratory support.

CONCLUSIONS

Our results can be translated into a clinical risk algorithm to identify children at risk of very severe RSV disease.

Antibiotic Utilization in Hospitalized Children with Bronchiolitis: A Prospective Study Investigating Clinical and Epidemiological Characteristics at a Secondary Hospital in Madrid (2004-2022)

Bronchiolitis is a viral respiratory infection, with respiratory syncytial virus (RSV) being the most frequent agent, requiring hospitalization in 1% of affected children. However, there continues to be a noteworthy incidence of antibiotic prescription in this setting, further exacerbating the global issue of antibiotic resistance. This study, conducted at Severo Ochoa Hospital in Madrid, Spain, focused on antibiotic usage in children under 2 years of age who were hospitalized for bronchiolitis between 2004 and 2022. In that time, 5438 children were admitted with acute respiratory infection, and 1715 infants (31.5%) with acute bronchiolitis were included. In total, 1470 (87%) had a positive viral identification (66% RSV, 32% HRV). Initially, antibiotics were prescribed to 13.4% of infants, but this percentage decreased to 7% during the COVID-19 pandemic thanks to adherence to guidelines and the implementation of rapid and precise viral diagnostic methods in the hospital. HBoV- and HAdV-infected children and those with viral coinfections were more likely to receive antibiotics in the univariate analysis. A multivariate logistic regression analysis revealed a statistically independent association between antibiotic prescription and fever > 38 °C (p < 0.001), abnormal chest-X ray (p < 0.001), ICU admission (p = 0.015), and serum CRP (p < 0.001). In conclusion, following guidelines and the availability of rapid and reliable viral diagnostic methods dramatically reduces the unnecessary use of antibiotics in infants with severe bronchiolitis.

Effects of Chest Physiotherapy in Preterm Infants with Respiratory Distress Syndrome: A Systematic Review

Preterm birth carries a higher risk of respiratory problems. The objectives of the study are to summarize the evidence on the effect of chest physiotherapy in the treatment of respiratory difficulties in preterm infants, and to determine the most appropriate technique and whether they are safe. Searches were made in PubMed, WOS, Scopus, Cochrane Library, SciELO, LILACS, MEDLINE, ProQuest, PsycArticle and VHL until 30 April 2022. Eligibility criteria were study type, full text, language, and treatment type. No publication date restrictions were applied. The MINCIR Therapy and PEDro scales were used to measure the methodological quality, and the Cochrane risk of bias and Newcastle Ottawa quality assessment Scale to measure the risk of bias. We analysed 10 studies with 522 participants. The most common interventions were conventional chest physiotherapy and stimulation of the chest zone according to Vojta. Lung compression and increased expiratory flow were also used. Heterogeneities were observed regarding the duration of the interventions and the number of participants. The methodological quality of some articles was not adequate. All techniques were shown to be safe. Benefits were described after conventional chest physiotherapy, Vojta's reflex rolling, and lung compression interventions. Improvements after Vojta's reflex rolling are highlighted in the comparative studies.

Identification of potential immune/diagnosis related gene-immunocyte subtype networks in extracellular immune response to respiratory syncytial virus infection

INTRODUCTION

Respiratory syncytial virus (RSV) is one of the important pathogenic agents of pediatric respiratory tract infection. Weighted gene co-expression network analysis (WGCNA) is used to study autoimmune diseases, which can find potential hub genes. The diagnostic model based on hub genes and machine learning makes it possible to diagnose the extracellular immune response to RSV infection early.

OBJECTIVE

The aim of the present study was to identify potential immune, diagnose and treatment related genes expressed in RSV-infected cells.

METHODS

Firstly, gene expression data were downloaded from the Gene Expression Omnibus (GEO) to identify differentially expressed genes (DEGs). Secondly, WGCNA was performed based on DEGs to obtain hub genes related to immunity score. Thirdly, protein-protein interaction (PPI) and the immune infiltration analysis of hub immune related genes were performed. Finally, diagnostic and immune related genes were identified by machine learning, followed by functional analysis.

RESULTS

Totally, 2063 DEGs were identified in the extracellular immune response to RSV infection. Among which, 10 key immune and diagnosis related genes were identified, including ITGA2B, GP9, ITGB3, SELP, PPBP, MPL, CXCL8, NFE2, PTGS1 and LY6G6F. Several immune/diagnosis related gene-immunocyte subtype networks were identified, such as CXCL8-Type 17 T helper cell, LY6G6F-CD56 bright natural killer cell, PPBP-activated CD4 T cell/T follicular helper cell, NFE2/PTGS1/SELP-activated dendritic cell, GP9/ITGA2B/MPL-activated CD8 T cell. ITGB3, MPL and PTGS1 could be considered as therapeutic targets. Some significantly enriched signaling pathways were identified, including hematopoietic cell lineage (involving GP9 and ITGA2B), cytokine-cytokine receptor interaction (involving MPL), chemokine signaling pathway (involving PPBP) and arachidonic acid metabolism (involving PTGS1).

CONCLUSIONS

The 10-immune related gene signature may be used as potential diagnostic markers for the extracellular immune response to RSV infection, which may provide a new field in searching for diagnostic and therapeutic molecules in the extracellular immune response to RSV infection.

Mucosal Immune Responses to Respiratory Syncytial Virus

Despite over half a century of research, respiratory syncytial virus (RSV)-induced bronchiolitis remains a major cause of hospitalisation in infancy, while vaccines and specific therapies still await development. Our understanding of mucosal immune responses to RSV continues to evolve, but recent studies again highlight the role of Type-2 immune responses in RSV disease and hint at the possibility that it dampens Type-1 antiviral immunity. Other immunoregulatory pathways implicated in RSV disease highlight the importance of focussing on localised mucosal responses in the respiratory mucosa, as befits a virus that is essentially confined to the ciliated respiratory epithelium. In this review, we discuss studies of mucosal immune cell infiltration and production of inflammatory mediators in RSV bronchiolitis and relate these studies to observations from peripheral blood. We also discuss the advantages and limitations of studying the nasal mucosa in a disease that is most severe in the lower airway. A fresh focus on studies of RSV pathogenesis in the airway mucosa is set to revolutionise our understanding of this common and important infection.

Respiratory Syncytial Virus-Associated Acute Lower Respiratory Infections in Children With Bronchopulmonary Dysplasia: Systematic Review and Meta-Analysis

BACKGROUND

Respiratory syncytial virus (RSV) is among the most important causes of acute lower respiratory tract infection (ALRI) in young children. We assessed the severity of RSV-ALRI in children less than 5 years old with bronchopulmonary dysplasia (BPD).

METHODS

We searched for studies using EMBASE, Global Health, and MEDLINE. We assessed hospitalization risk, intensive care unit (ICU) admission, need for oxygen supplementation and mechanical ventilation, and in-hospital case fatality (hCFR) among children with BPD compared with those without (non-BPD). We compared the (1) length of hospital stay (LOS) and (2) duration of oxygen supplementation and mechanical ventilation between the groups.

RESULTS

Twenty-nine studies fulfilled our inclusion criteria. The case definition for BPD varied substantially in the included studies. Risks were higher among children with BPD compared with non-BPD: RSV hospitalization (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.7-4.2; P < .001), ICU admission (OR, 2.9; 95% CI, 2.3-3.5; P < .001), need for oxygen supplementation (OR, 4.2; 95% CI, .5-33.7; P = .175) and mechanical ventilation (OR, 8.2; 95% CI, 7.6-8.9; P < .001), and hCFR (OR, 12.8; 95% CI, 9.4-17.3; P < .001). Median LOS (range) was 7.2 days (4-23) (BPD) compared with 2.5 days (1-30) (non-BPD). Median duration of oxygen supplementation (range) was 5.5 days (0-21) (BPD) compared with 2.0 days (0-26) (non-BPD). The duration of mechanical ventilation was more often longer (>6 days) in those with BPD compared with non-BPD (OR, 11.9; 95% CI, 1.4-100; P = .02).

CONCLUSIONS

The risk of severe RSV disease is considerably higher among children with BPD. There is an urgent need to establish standardized BPD case definitions, review the RSV prophylaxis guidelines, and encourage more specific studies on RSV infection in BPD patients, including vaccine development and RSV-specific treatment.

Acute Lower Respiratory Infections Associated With Respiratory Syncytial Virus in Children With Underlying Congenital Heart Disease: Systematic Review and Meta-analysis

BACKGROUND

Respiratory syncytial virus (RSV) is the most common viral pathogen associated with acute lower respiratory infections (ALRIs), with significant childhood morbidity and mortality worldwide. Estimates reporting RSV-associated ALRI (RSV-ALRI) severity in children with congenital heart disease (CHD) are lacking, thus warranting the need to summarize the available data. We identified relevant studies to summarize the findings and conducted a meta-analysis of available data on RSV-associated ALRI hospitalizations in children aged <5 years, comparing those with underlying CHD to those without CHD.

METHODS

We conducted a systematic search of existing relevant literature and identified studies reporting hospitalization of children aged <5 years with RSV-ALRI with underlying or no CHD. We summarized the data and conducted (where possible) a random-effects meta-analysis to compare the 2 groups.

RESULTS

We included 18 studies that met our strict eligibility criteria. The risk of severe RSV-ALRI (odds ratio, 2.2; 95% confidence interval [CI], 1.6-2.8), the rate of hospitalization (incidence rate ratio, 2.8; 95% CI, 1.9-4.1), and the case-fatality ratio (risk ratio [RR], 16.5; 95% CI, 13.7-19.8) associated with RSV-ALRI was higher among children with underlying CHD as compared to those without no CHD. The risk of admission to the intensive care unit (RR, 3.9; 95% CI, 3.4-4.5), need for supplemental oxygen therapy (RR, 3.4; 95% CI, .5-21.1), and need for mechanical ventilation (RR, 4.1; 95% CI, 2.1-8.0) was also higher among children with underlying CHD.

CONCLUSION

This is the most detailed review to show more-severe RSV-ALRI among children aged <5 years with underlying CHD, especially hemodynamically significant underlying CHD, as compared those without CHD, supporting a need for improved RSV prophylactics and treatments that also have efficacy in children older than 1 year.

Risk factors for RSV associated acute lower respiratory infection poor outcome and mortality in young children: A systematic review and meta-analysis

Respiratory syncytial virus associated acute lower respiratory infection (RSV-ALRI) constitutes a substantial disease burden in young children. We aimed to identify all studies investigating the risk factors of RSV-ALRI poor outcome or mortality in young children.We carried out a systematic literature review across 7 databases with data from studies published from January 1995 to December 2019. We defined poor outcome as need for prolonged hospital stay, oxygen supplementation, mechanical ventilation or intensive care unit (ICU) admission. Quality of all eligible studies was assessed according to modified GRADE criteria. We conducted meta-analyses to estimate odds ratio (OR) with 95% confidence intervals (CI) for individual risk factors. We identified 27 eligible studies, which investigated 20 risk factors for RSV-ALRI poor outcome and/or mortality in children younger than 5 years old, in comparison to those with RSV-ALRI who did not have poor outcome or mortality. Among those risk factors, 6 had statistically significant associations with RSV-ALRI poor outcome: any comorbidity (OR 2.69 (95% CI 1.89-3.83)), congenital heart disease (3.40 (95% CI 2.14-5.40)), prematurity with gestational age (GA) <37 weeks (1.75 (95% CI 1.31-2.36)), prematurity with GA ≤32 weeks (2.68 (95% CI 1.43-5.04)), age <3 months (4.91 (95% CI 1.64-14.71)), age <6 months (2.02 (95% CI 1.73-2.35)). Apart from age <3 months, the meta-estimate ORs for all other risk factors were based on studies using multivariable analysis. For mortality, only prematurity with GA <37 weeks had a significant meta-estimate of OR 3.81 (95% CI 1.68-8.63) based on univariable analysis.This study represents a comprehensive report of the association between various risk factors and RSV-ALRI poor outcome and mortality in young children. More research should be carried out to elucidate risk factors associated with poor outcome and mortality using multivariable analysis.

Variability of Care of Infants With Severe Respiratory Syncytial Virus Bronchiolitis: A Multicenter Study

BACKGROUND

Viral bronchiolitis caused by respiratory syncytial virus (RSV) is a common childhood disease accounting for many hospitalizations worldwide. Some infants may clinically deteriorate, requiring admission to an intensive care unit. We aimed to describe diagnostic and therapeutic measures of bronchiolitis in Israeli pediatric intensive care units (PICUs) and evaluate intercenter variability of care.

METHODS

Medical records of all RSV-infected infants admitted to 5 Israeli PICUs over 4 RSV seasons were retrospectively reviewed.

RESULTS

Data on 276 infants with RSV-positive bronchiolitis, admitted to the participating PICUs were analyzed. Most of the infants were males with a mean admission age of 4.7 months. Approximately half of the infants had pre-existing conditions such as prematurity, cardiac disease or chronic lung disease. Respiratory distress was the most common symptom at presentation followed by hypoxemia and fever. There was significant variation in the methods used for RSV diagnosis, medical management and respiratory support of the infants. Furthermore, utilization of inhalational therapy and transfusion of blood products differed significantly between the centers. Although a bacterial pathogen was isolated in only 13.4% of the infants, 82.6% of the cohort was treated with antibiotics.

CONCLUSIONS

Significant variation was found between the different PICUs regarding RSV bronchiolitis diagnosis, medical management and respiratory support, which may not be accounted for by the differences in baseline and clinical characteristics of the infants. Some of these differences may be explained by uneven resource allocations. This diversity and the documented routine use of medications with weak evidence of efficacy calls for national guidelines for bronchiolitis management.

Host and Viral Determinants of Respiratory Syncytial Virus-induced Airway Mucus

Respiratory syncytial virus (RSV) is a leading cause of hospitalization of infants worldwide each year. Both host and viral factors host factors predispose a subset of what appear to be healthy infants to severe RSV-induced disease. In this review, we outline many genetic and immunologic factors that contribute to airway obstruction that contributes to the severity of RSV infection.

Levels of Soluble Urokinase Plasminogen Activator Receptor in Pediatric Lower Respiratory Tract Infections

Background: Lower respiratory tract infections (LTRIs) are the most common cause of pediatric emergency department visits and are associated with significant morbidity and mortality. The aim of this study was to evaluate the soluble urokinase plasminogen activator receptor (suPAR) levels in pediatric patients with LRTIs and to investigate the correlation of suPAR with disease severity. Methods: This is a prospective case-control study of children with LTRIs. Demographic data, diagnoses, vital signs, disease severity scores, length of hospital stay, laboratory findings, and viral polymerase chain reaction results for nasopharyngeal aspirates were recorded. Blood samples for suPAR were collected and assessed by enzyme-linked immunosorbent assay. Results: There were 94 patients with LTRIs and 32 children in the control group. Patients were further subdivided into 2 groups based on diagnosis of acute bronchiolitis (n: 31, 33%) or pneumonia (n: 63, 67%). The median levels of suPAR were significantly higher in patients with LTRIs than in healthy controls (4.3 and 3.5 ng/mL, respectively; P = 0.003). There was an association between suPAR levels and disease severity in pneumonia patients. suPAR values were higher in patients with severe pneumonia than mild pneumonia (5.5 and 3.6 ng/mL, respectively; P < 0.001). Conclusion: We have shown that suPAR levels increased in patients with LTRIs and suPAR values were higher in patients with severe pneumonia than mild pneumonia. Further studies with large case series are needed to clarify the role of suPAR levels in children with LTRIs.

Pediatric intensive care unit admission due to respiratory syncytial virus: Retrospective multicenter study

BACKGROUND

We investigated the characteristics and clinical outcomes of respiratory syncytial virus (RSV)-related pediatric intensive care unit (PICU) hospitalization and assessed the palivizumab (PZ) prophylaxis eligibility according to different guidelines from Korea, EU, and USA.

METHODS

In this multicenter study, children <18 years of age hospitalized in six PICU from different hospitals due to severe RSV infection between September 2008 and March 2013 were included. A retrospective chart review was performed.

RESULTS

A total of 92 patients were identified. The median length of PICU stay was 6 days (range, 1-154 days) and median PICU care cost was USD2,741 (range, USD556-98 243). Of 62 patients who were <2 years old at the beginning of the RSV season, 33 (53.2%) were high-risk patients for severe RSV infection. Hemodynamically significant congenital heart disease (22.6%) was the most common risk factor, followed by chronic lung disease (11.3%), neuromuscular disease or congenital abnormality of the airway (NMD/CAA) (11.3%), and prematurity (8.1%). The percentage of patients eligible for PZ prophylaxis ranged from 38.7% to 48.4% based on the guidelines, but only two (2.2%) received PZ ≤30 days prior to PICU admission. The median duration of mechanical ventilation was longer in children with NDM/CAA than in those without risk factors (26 days; range, 24-139 days vs 6 days, range, 2-68 days, P = 0.033). RSV-attributable mortality was 5.4%.

CONCLUSIONS

Children <2 years old with already well-known high risks represent a significant proportion of RSV-related PICU admissions. Increasing of the compliance for PZ prophylaxis practice among physicians is needed. Further studies are needed to investigate the burden of RSV infection in patients hospitalized in PICU, including children with NMD/CAA.

Decreased microRNA-140-5p contributes to respiratory syncytial virus disease through targeting Toll-like receptor 4

The abnormal expression of miRNAs (miRs) has previously been reported in respiratory syncytial virus (RSV) disease. However, to the best of our knowledge, the expression of miR-140-5p in patients with an RSV infection has never been explored. Reverse transcription-quantitative polymerase chain reaction was performed to analyze the level of miR-140-5p in the blood and nasopharyngeal airway samples. ELISAs were performed to determine the levels of tumor necrosis factor α, interleukin (IL)-1β, IL-6 and IL-8. A dual luciferase reporter assay was also performed to investigate the possible target gene of miR-140-5p. The results demonstrated that the levels of miR-140-5p were significantly decreased in the nasal mucosal and peripheral blood samples of patients with RSV infection. It was also revealed that overexpression of miR-140-5p decreased the inflammatory responses, while inhibition of miR-140-5p enhanced the inflammatory responses. Additionally, three binding sites of miR-140-5p in the 3untranslated region (UTR) of Toll-like receptor (TLR)4 were identified and a dual luciferase reporter assay demonstrated that miR-140-5p significantly suppressed the relative luciferase activity of pmirGLO-TLR4-3UTR. Furthermore, the level of miR-140-5p was shown to be increased following interferon (IFN)α incubation. Notably, inhibition of miR-140-5p markedly attenuated IFNα-mediated downregulation of tumor necrosis factor α, and interleukin-1β, -6 and -8 in BEAS-2B cells. In summary, decreased miR-140-5p levels are involved in RSV-infection diseases primarily through targeting TLR4.

Global respiratory syncytial virus-associated mortality in young children (RSV GOLD): a retrospective case series

Background

Respiratory syncytial virus (RSV) infection is an important cause of pneumonia mortality in young children. However, clinical data for fatal RSV infection are scarce. We aimed to identify clinical and socioeconomic characteristics of children aged younger than 5 years with RSV-related mortality using individual patient data.

Methods

In this retrospective case series, we developed an online questionnaire to obtain individual patient data for clinical and socioeconomic characteristics of children aged younger than 5 years who died with community-acquired RSV infection between Jan 1, 1995, and Oct 31, 2015, through leading research groups for child pneumonia identified through a comprehensive literature search and existing research networks. For the literature search, we searched PubMed for articles published up to Feb 3, 2015, using the key terms “RSV”, “respiratory syncytial virus”, or “respiratory syncytial viral” combined with “mortality”, “fatality”, “death”, “died”, “deaths”, or “CFR” for articles published in English. We invited researchers and clinicians identified to participate between Nov 1, 2014, and Oct 31, 2015. We calculated descriptive statistics for all variables.

Findings

We studied 358 children with RSV-related in-hospital death from 23 countries across the world, with data contributed from 31 research groups. 117 (33%) children were from low-income or lower middle-income countries, 77 (22%) were from upper middle-income countries, and 164 (46%) were from high-income countries. 190 (53%) were male. Data for comorbidities were missing for some children in low-income and middle-income countries. Available data showed that comorbidities were present in at least 33 (28%) children from low-income or lower middle-income countries, 36 (47%) from upper middle-income countries, and 114 (70%) from high-income countries. Median age for RSV-related deaths was 5·0 months (IQR 2·3–11·0) in low-income or lower middle-income countries, 4·0 years (2·0–10·0) in upper middle-income countries, and 7·0 years (3·6–16·8) in high-income countries.

Interpretation

This study is the first large case series of children who died with community-acquired RSV infection. A substantial proportion of children with RSV-related death had comorbidities. Our results show that perinatal immunisation strategies for children aged younger than 6 months could have a substantial impact on RSV-related child mortality in low-income and middle-income countries.

Funding

Bill & Melinda Gates Foundation.

Altered regulatory cytokine profiles in cases of pediatric respiratory syncytial virus infection

Objectives

Regulatory cytokines are associated with viral infection. The objective of this study was to evaluate the relation between serum regulatory cytokines concentrations and respiratory syncytial virus (RSV) disease.

Methods

We enrolled 325 children aged < 24 months who were diagnosed with acute respiratory tract infection. Twenty age-matched healthy children were enrolled as controls. Nasopharyngeal swabs were analyzed to identify virus by reverse transcription polymerase chain reaction, and blood samples were taken to quantify the regulatory cytokine concentrations, including interleukin (IL)-35, IL-10 and transforming growth factor (TGF)-β1 using the Bio-Plex immunoassay or enzyme-linked immunosorbent assay.

Results

RSV disease was associated with a great regulatory cytokine response than healthy children, among 89 RSV-infected patients, serum IL-35 (P = .0001) and IL-10 (P = .006) was significantly elevated in comparison with healthy controls. Young children (0< age ≤6 months) with RSV infection had significantly lower IL-35 and IL-10 expression but needed more oxygen therapy and more severe disease comparing with older children (12< age <24 months). Comparing with mild group, the expression levels of IL-10 were significantly lower in children with moderate and severe disease (P = .012 and P = .005, respectively). And levels of IL-10 was inversely associated with total duration of RSV infection symptoms (r = − 0.311, P = .019).

Conclusion

Children with RSV infected had increased serum regulatory cytokine IL-10 and IL-35 concentrations. Elevated expression of IL-10 and IL-35 were contributed to protect hypoxia and reduce the severity of disease.

Prospective observational study in two Dutch hospitals to assess the performance of inflammatory plasma markers to determine disease severity of viral respiratory tract infections in children

INTRODUCTION

Respiratory viruses causing lower respiratory tract infections (LRTIs) are a major cause of hospital admissions in children. Since the course of these infections is unpredictable with potential fast deterioration into respiratory failure, infants are easily admitted to the hospital for observation. The aim of this study was to examine whether systemic inflammatory markers can be used to predict severity of disease in children with respiratory viral infections.

METHODS

Blood and nasopharyngeal washings from children <3 years of age with viral LRTI attending a hospital were collected within 24 hours (acute) and after 4-6 weeks (recovery). Patients were assigned to a mild (observation only), moderate (supplemental oxygen and/or nasogastric feeding) or severe (mechanical ventilation) group. Linear regression analysis was used to design a prediction rule using plasma levels of C reactive protein (CRP), serum amyloid A (SAA), pentraxin 3 (PTX3), serum amyloid P component and properdin. This rule was tested in a validation cohort.

RESULTS

One hundred and four children (52% male) were included. A combination of CRP, SAA, PTX3 and properdin was a better indicator of severe disease compared with any of the individual makers and age (69% sensitivity (95% CI 50 to 83), 90% specificity (95% CI 80 to 96)). Validation in 141 patients resulted in 71% sensitivity (95% CI 53 to 85), 87% specificity (95% CI 79 to 92), negative predictive value of 64% (95% CI 47 to 78) and positive predictive value of 90% (95% CI 82 to 95). The prediction rule was not able to identify patients with a mild course of disease.

CONCLUSION

A combination of CRP, SAA, PTX3 and properdin was able to identify children with a severe course of viral LRTI disease, even in children under 2 months of age. To assess the true impact on clinical management, these results should be validated in a prospective randomised control study.

Prospective Multicentre Study on the Epidemiology and Current Therapeutic Management of Severe Bronchiolitis in Spain

Objective. To determine the epidemiology and therapeutic management of patients with severe acute bronchiolitis (AB) admitted to paediatric intensive care units (PICUs) in Spain. Design. Descriptive, prospective, multicentre study. Setting. Sixteen Spanish PICUs. Patients. Patients with severe AB who required admission to any of the participating PICUs over 1 year. Interventions. Both epidemiological variables and medical treatment received were recorded. Results. A total of 262 patients were recruited; 143 were male (54.6%), with median age of 1 month (0–23). Median stay in the PICU was 7 days (1–46). Sixty patients (23%) received no nebuliser treatment, while the rest received a combination of inhalation therapies. One-quarter of patients (24.8%) received corticosteroids and 56.5% antibiotic therapy. High-flow oxygen therapy was used in 14.3% and noninvasive ventilation (NIV) was used in 75.6%. Endotracheal intubation was required in 24.4% of patients. Younger age, antibiotic therapy, and invasive mechanical ventilation (IMV) were risk factors that significantly increased the stay in the PICU. Conclusions. Spanish PICUs continue to routinely use nebulised bronchodilator treatment and corticosteroid therapy. Despite NIV being widely used in this condition, intubation was required in one-quarter of cases. Younger age, antibiotic therapy, and IMV were associated with a longer stay in the PICU.

Defining the Risk and Associated Morbidity and Mortality of Severe Respiratory Syncytial Virus Infection Among Infants with Chronic Lung Disease

INTRODUCTION

The REGAL (RSV evidence-a geographical archive of the literature) series provide a comprehensive review of the published evidence in the field of respiratory syncytial virus (RSV) in Western countries over the last 20 years. This third publication covers the risk and burden of RSV infection in infants with chronic lung disease (CLD), formerly called bronchopulmonary dysplasia (BPD).

METHODS

A systematic review was undertaken of publications between January 1, 1995 and December 31, 2015 across PubMed, Embase, The Cochrane Library, and Clinicaltrials.gov. Studies reporting data for hospital visits/admissions for RSV infection among infants with CLD/BPD who were not prophylaxed, as well as studies reporting RSV-associated morbidity, mortality, and healthcare costs, were included. Burdens of disease data were compared with preterm infants without CLD/BPD, other high-risk groups and term infants. Study quality and strength of evidence (SOE) were graded using recognized criteria.

RESULTS

A total of 1837 studies were identified and 39 were included. CLD/BPD is a significant independent risk factor for RSV hospitalization [RSVH (odds ratio 2.2-7.2); high SOE]. Infants and young children with CLD/BPD had high RSVH rates which were generally similar in Europe, the United States, and Canada, mostly varying between 12 and 21%. Infants with CLD also had a longer length of hospital stay than other high-risk groups and term infants (high SOE). On average, infants spent 4-11 days in hospital (moderate SOE). Once hospitalized for RSV, affected children were at risk for a more severe course of disease than children with no RSVH (moderate SOE).

CONCLUSION

Severe RSV infection in infants and young children with CLD/BPD poses a significant health burden in Western countries. Further studies focussing on the burden of RSV infection in this well-recognized population at high risk for severe disease are needed to help improve outcomes and plan allocation of healthcare resources.

FUNDING

AbbVie.

Transcriptome assists prognosis of disease severity in respiratory syncytial virus infected infants

Respiratory syncytial virus (RSV) causes infections that range from common cold to severe lower respiratory tract infection requiring high-level medical care. Prediction of the course of disease in individual patients remains challenging at the first visit to the pediatric wards and RSV infections may rapidly progress to severe disease. In this study we investigate whether there exists a genomic signature that can accurately predict the course of RSV. We used early blood microarray transcriptome profiles from 39 hospitalized infants that were followed until recovery and of which the level of disease severity was determined retrospectively. Applying support vector machine learning on age by sex standardized transcriptomic data, an 84 gene signature was identified that discriminated hospitalized infants with eventually less severe RSV infection from infants that suffered from most severe RSV disease. This signature yielded an area under the receiver operating characteristic curve (AUC) of 0.966 using leave-one-out cross-validation on the experimental data and an AUC of 0.858 on an independent validation cohort consisting of 53 infants. A combination of the gene signature with age and sex yielded an AUC of 0.971. Thus, the presented signature may serve as the basis to develop a prognostic test to support clinical management of RSV patients.

Respiratory Syncytial Virus-associated hospitalization in premature infants who did not receive palivizumab prophylaxis in Italy: a retrospective analysis from the Osservatorio Study

BACKGROUND

Due to different social and epidemiological factors, the eligibility criteria to receive palivizumab prophylaxis may be different between countries, especially in "otherwise healthy" late preterm infants.

METHODS

We analyzed an Italian database of young children referred to emergency departments for acute lower respiratory tract infection (ALRI) during the RSV season over a four year period, when the use of palivizumab as prophylaxis for RSV disease was not widespread in premature infants. The demographic and environmental characteristics and the RSV positivity (RSV(+)) in hospitalized and not-hospitalized patients were compared. In the data analysis we divided children according to their chronologic age (age) and their week gestational age (wGA).

RESULTS

Out of the 100 children evaluated, 68 were infants (≤12 month-age): 7.5 and 20.6 % were in the <29 and 29- < 32 wGA groups respectively, and 72.0 % in the 32- < 35 wGA group. Positive hospitalized-to-not-hospitalized ratios were found in all three wGA groups, progressively decreasing (from 4.0 to 1.2), with increasing wGA (p = 0.35). The percentage of hospitalized infants that were also RSV(+) was also progressively decreasing (from 40.0 to 28.6 % and 18.4 %) with increasing wGA (p = 0.43). In the >12 month-age group (N = 32), there was positive hospitalized-to-not-hospitalized ratio only in the <29 wGA group with a low RSV(+) frequency (<29 %) in all wGA groups. In the ≤12 month-age group, 41 infants were evaluated with a ≤6 month-age and 27 with a >6-12 month-age. A positive hospitalized-to-not-hospitalized ratios was found in all wGA groups in ≤6 month-age infants, despite a low RSV(+) frequency in the 29- < 32 and 32- < 35 wGA group. In the >6-12 month-age group, all infants with a <29 and 29- < 32 wGA were hospitalized with a relatively high RSV(+) frequency whilst the 32- < 35 wGA group showed a negative hospitalized-to-not-hospitalized ratio with a lower RSV(+) frequency.

CONCLUSIONS

The hospitalized-to-not-hospitalized ratios and RSV(+) frequency in the first 12 months of age in infants born prematurely confirm the vulnerability of these children for clinically important RSV infection, most notably in the <32 wGA category.

The influence of birth weight amongst 33-35 weeks gestational age (wGA) infants on the risk of respiratory syncytial virus (RSV) hospitalisation: a pooled analysis

OBJECTIVE

To investigate the association between birth weight and respiratory syncytial virus (RSV) hospitalisation during the first year of life in 33°-35⁶ weeks' gestational age (wGA) infants.

STUDY DESIGN

Pooled analysis of data (n = 1218) from Spain, Germany, France and Italy.

RESULT

RSV hospitalised infants overall had a significantly higher birth weight than non-hospitalised infants (2.24 versus 2.14 kg; p < 0.001) for both males (2.25 versus 2.18 kg; p = 0.049) and females (2.22 versus 2.11 kg, p = 0.007). The effect was significant only in 34 wGA infants (33 wGA: hospitalised 1.95 kg versus non-hospitalised 1.95 kg, p = 0.976; 34 wGA: 2.26 versus 2.14 kg, p = 0.007; 35 wGA: 2.37 versus 2.29 kg, p = 0.070), particularly female 34 wGA infants (female: 2.24 versus 2.08 kg, p = 0.019; male: 2.27 versus 2.20, p = 0.191). Birth weight was shown to be an independent risk factor for RSV hospitalisation.

CONCLUSIONS

In 33-35 wGA infants, a higher birth weight appeared independently associated with an increased risk of RSV hospitalisation.

Prematurity and the burden of influenza and respiratory syncytial virus disease

BACKGROUND

Respiratory morbidity of former preterm infants and especially those with bronchopulmonary dysplasia (BPD) is high during infancy and early childhood.

DATA SOURCES

We performed a review based on a literature search including EMBASE, MEDLINE, and CINAHL databases to identify all relevant papers published in the English and German literature on influenza and respiratory syncytial virus infection associated with preterm infant, prematurity, and BPD between 1980 and 2014.

RESULTS

Recurrent respiratory symptoms remain common at preschool age, school age and even into young adulthood. Acute viral respiratory tract infections due to different pathogens cause significant morbidity and necessitate rehospitalizations during the first years of life. Influenza virus infection plays a minor role compared to respiratory syncytial virus (RSV) associated respiratory tract infection during infancy and early childhood. Nevertheless, particular morbidity to both viruses is high.

CONCLUSIONS

The particular burden of both viral diseases in preterm infants is dominated by RSV and its associated rehospitalizations during the first two years of life. Prophylactic measures include vaccination against influenza virus of family members and caregivers and active immunization starting at the age of 6 months, and monthly injections of palivizumab during the cold season to avoid severe RSV disease and its sequelae.

High Frequency Jet Ventilation in Respiratory Failure Secondary to Respiratory Syncytial Virus Infection: A Case Series

OBJECTIVE

To describe the utility of high frequency jet ventilation (HFJV) as a rescue therapy in patients with respiratory failure secondary to respiratory syncytial virus (RSV) that was refractory to conventional mechanical ventilation (CMV).

DESIGN

Descriptive study by retrospective review.

SETTING

Pediatric intensive care unit at a tertiary care children's hospital.

PATIENTS

Infants on mechanical ventilation for respiratory failure due to RSV.

INTERVENTIONS

Use of HFJV.

MAIN RESULTS

Eleven patients were placed on HFJV. There was sustained improvement in ventilation on HFJV with a mean decrease in PCO2 of 9 mmHg at 24 h and 11 mmHg at 72 h. There were no significant changes in oxygenation by oxygenation index. No patients required extracorporeal support or suffered pneumothorax, pneumomediastinum, or subcutaneous emphysema. Ten out of 11 (91%) patients survived to discharge from the hospital.

CONCLUSION

High frequency jet ventilation may represent an alternative therapy for RSV-induced respiratory failure that is refractory to CMV.

Respiratory syncytial virus infection inhibits TLR4 signaling via up-regulation of miR-26b

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract illnesses in infants worldwide. TLR4 signal pathway plays a critical role in regulating immune response against RSV infection. However, the activation of TLR4 in RSV infection is still unclear. In present study, the expression levels of miR-26b and TLR4 mRNA were detected in peripheral blood mononuclear cells (PBMCs) of children with or without RSV infected bronchiolitis. The expression levels of TLR4 and its downstream genes IFNβ and CCL5 were also quantified in PBMCs infected with RSVΔG or RSV A2 in vitro. The results showed that children with RSV infection had higher miR-26b level and lower TLR4 mRNA level in PBMCs. miR-26b was predicted to target TLR4. In vitro, miR-26b mimic markedly down-regulated TLR4 mRNA/protein expression and IFNβ/CCL5 concentrations while miR-26b inhibitor up-regulated these levels. This study reveals that RSV infection inhibits TLR4 signaling via up-regulation of miR-26b, which provides a potential therapeutic target for preventing and treating RSV infection.

Olfactomedin 4 Serves as a Marker for Disease Severity in Pediatric Respiratory Syncytial Virus (RSV) Infection

Background

Respiratory viral infections follow an unpredictable clinical course in young children ranging from a common cold to respiratory failure. The transition from mild to severe disease occurs rapidly and is difficult to predict. The pathophysiology underlying disease severity has remained elusive. There is an urgent need to better understand the immune response in this disease to come up with biomarkers that may aid clinical decision making.

Methods

In a prospective study, flow cytometric and genome-wide gene expression analyses were performed on blood samples of 26 children with a diagnosis of severe, moderate or mild Respiratory Syncytial Virus (RSV) infection. Differentially expressed genes were validated using Q-PCR in a second cohort of 80 children during three consecutive winter seasons. FACS analyses were also performed in the second cohort and on recovery samples of severe cases in the first cohort.

Results

Severe RSV infection was associated with a transient but marked decrease in CD4+ T, CD8+ T, and NK cells in peripheral blood. Gene expression analyses in both cohorts identified Olfactomedin4 (OLFM4) as a fully discriminative marker between children with mild and severe RSV infection, giving a PAM cross-validation error of 0%. Patients with an OLFM4 gene expression level above -7.5 were 6 times more likely to develop severe disease, after correction for age at hospitalization and gestational age.

Conclusion

By combining genome-wide expression profiling of blood cell subsets with clinically well-annotated samples, OLFM4 was identified as a biomarker for severity of pediatric RSV infection.

Pattern of Viral Infections among Infants and Children Admitted to the Paediatric Intensive Care Unit at Sultan Qaboos University Hospital, Oman

OBJECTIVES

The aim of this study was to describe the pattern of viral infections in infants and children admitted to the Paediatric Intensive Care Unit (PICU) at Sultan Qaboos University Hospital (SQUH) in Muscat, Oman.

METHODS

A retrospective review of patient records was carried out on all patients admitted to the PICU between January 2011 and December 2012. In order to detect viruses, polymerase chain reaction (PCR) technology was used to detect viruses in nasopharyngeal aspirates, tracheal aspirates, plasma, stool and urine samples. All infants and children below 13 years old, who were admitted to the PICU at SQUH during the study period and with confirmed viral infections, were included in the study.

RESULTS

A total of 373 infants and children were admitted to the PICU during the study period. Viruses were detected in 34 patients. The most frequently detected viruses were cytomegalovirus (CMV) in 29.4%; this virus was noted predominantly in immuncompromised patients (80%, P = 0.023) and was associated with increased mortality (50%, P = 0.031) and prolonged PICU stay (70%, P = 0.045). Fatalities before discharge were recorded in 23.5% of the patients. The most frequent risk factors for viral infections were an age of <12 months old (47.1%), assisted ventilation/intubation (52.9%) and a prolonged PICU stay (55.9%).

CONCLUSION

The results of this study found that CMV was the most common viral infection among infants and children admitted to the PICU in SQUH. CMV was also the leading cause of mortality.

Risk factors associated with death in patients with severe respiratory syncytial virus infection

BACKGROUND

Respiratory syncytial virus (RSV) infection is an important cause of viral respiratory tract infection in children. This retrospective study describes the clinical characteristics of severe RSV infection and determines the risk factors for death.

METHODS

Patients were identified through a review of all patients discharged with a diagnosis of RSV lower respiratory tract infection and admitted to hospital in the pediatric intensive care unit (PICU) of a tertiary medical center between July 1, 2001 and June 30, 2010. The medical and demographic variables were recorded and analyzed.

RESULTS

The 186 RSV-positive patients admitted to the PICU had a median age of 5.3 months (interquartile range 2.3-12.4 months) and included 129 boys and 57 girls. Among them, 134 had at least one underlying disease: prematurity in 92, neurological disease in 57, bronchopulmonary dysplasia in 40, congenital heart disease in 26, hematological malignancies in 11, and Down's syndrome in nine patients. The 10 patients who died from RSV-related causes had a median age of 20.8 months (interquartile range 6.6-89.2 months) and all had a comorbidity. In multivariate analysis, the risk factors for death in severe RSV infection were Down's syndrome (odds ratio 7.20, 95% confidence interval 1.13-45.76; p = 0.036) and nosocomial RSV infection (odds ratio 4.46, 95% confidence interval 1.09-18.27; p = 0.038).

CONCLUSION

Down's syndrome and nosocomial RSV infection are significantly associated with death in severe RSV infections. Clinicians should be alert to these conditions.

Nasopharyngeal gene expression, a novel approach to study the course of respiratory syncytial virus infection

Respiratory syncytial virus (RSV) causes mild infections in the vast majority of children. However, in some cases, it causes severe disease, such as bronchiolitis and pneumonia. Development of severe RSV infection is determined by the host response. Therefore, the main aim of this study was to identify biomarkers associated with severe RSV infection. To identify biomarkers, nasopharyngeal gene expression was profiled by microarray studies, resulting in the selection of five genes: ubiquitin D, tetraspanin 8, mucin 13, β-microseminoprotein and chemokine ligand 7. These genes were validated by real-time quantitative PCR in an independent validation cohort, which confirmed significant differences in gene expression between mildly and severely infected and between recovery and acute patients. Nasopharyngeal aspirate samples are regularly taken when a viral respiratory tract infection is suspected. In this article, we describe a method to discriminate between mild and severe RSV infection based on differential host gene expression. The combination of pathogen detection and host gene expression analysis in nasopharyngeal aspirates will significantly improve the diagnosis and prognosis of respiratory tract infections.

Prevention and prophylaxis of respiratory syncytial virus in pediatric cardiology: a UK perspective

ABSTRACT: 

Respiratory syncytial virus (RSV) is a common infection, causing bronchiolitis in over 70% of infants each year and almost all children by the age of 2. It is the leading cause of acute lower respiratory tract infections and admissions to hospital worldwide. Previously healthy infants may have a prolonged cough or wheezing following RSV infection but up to 20% of those with congenital cardiac disease will be hospitalized and have significant morbidity and mortality. For this reason, it is generally recommended that many such infants should receive prophylaxis against RSV infection with palivizumab. This paper reviews the current state of knowledge about RSV affecting children with congenital heart disease from the perspective of those living in the UK and the current protection offered to such children. We also discuss the plans for the future of protection against RSV.

Epidemiology and risk factors for severe respiratory syncytial virus infections requiring pediatric intensive care admission in Hong Kong children

PURPOSE

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in young children. However, there are limited data on severe RSV infection requiring pediatric intensive care unit (PICU) admission. This retrospective study described features of RSV-associated PICU admissions in Hong Kong and investigated factors for mortality and duration of PICU stay.

METHODS

Children with laboratory-confirmed RSV infection and admitted to the PICUs of all eight government hospitals in Hong Kong between January 2009 and June 2011 were identified from computerized auditing systems and PICU databases. RSV in respiratory samples was detected by direct immunofluorescence and/or viral culture. The relationships between mortality and PICU duration and demographic and clinical factors were analyzed.

RESULTS

A total of 118 (2.4 %) PICU admissions were identified among 4,912 RSV-positive pediatric cases in all hospitals. Sixty-five (55.6 %) patients were infants. PICU admissions were higher between October and March. Eight (6.8 %) patients died, but only two were infants. RSV-associated mortality was related to prior sick contact, presence of older siblings, neurodevelopmental conditions, chromosomal and genetic diseases, and bacterial co-infections, but none was significant following logistic regression analyses (odds ratio 9.36, 95 % confidence interval 0.91-96.03 for prior sick contact, p = 0.060). Chronic lung disease was the only risk factor for the duration of PICU admission (β = 0.218, p = 0.017).

CONCLUSIONS

The majority of RSV-infected children do not require PICU support. There is winter seasonality for RSV-associated PICU admission in Hong Kong. Prior sick contact is the only risk factor for RSV-associated mortality, whereas the presence of chronic lung disease is associated with longer PICU stay. The current risk-based approach of RSV prophylaxis may not be effective in reducing severe RSV infections.

CD4+ T-cell counts and interleukin-8 and CCL-5 plasma concentrations discriminate disease severity in children with RSV infection

BACKGROUND

Current tools to predict the severity of respiratory syncytial virus (RSV) infection might be improved by including immunological parameters. We hypothesized that a combination of inflammatory markers would differentiate between severe and mild disease in RSV-infected children.

METHODS

Blood and nasopharyngeal samples from 52 RSV-infected children were collected during acute infection and after recovery. Retrospectively, patients were categorized into three groups based on disease severity: mild (no supportive treatment), moderate (supplemental oxygen and/or nasogastric feeding), and severe (mechanical ventilation). Clinical data, number of flow-defined leukocyte subsets, and cytokine concentrations were compared.

RESULTS

Children with severe RSV infection were characterized by young age; lymphocytopenia; increased interleukin (IL)-8, granulocyte colony-stimulating factor (G-CSF), and IL-6 concentrations; and decreased chemokine (C-C motif) ligand (CCL-5) concentrations in plasma. The combination of plasma levels of IL-8 and CCL-5, and CD4+ T-cell counts, with cutoff values of 67 pg/ml, 13 ng/ml, and 2.3 × 10(6)/ml, respectively, discriminated severe from mild RSV infection with 82% sensitivity and 96% specificity.

CONCLUSION

This study demonstrates that the combination of CD4+ T-cell counts and IL-8 and CCL-5 plasma concentrations correlates with disease severity in RSV-infected children. In addition to clinical features, these immunological markers may be used to assess severity of RSV infection and guide clinical management.

Innate immune dysfunction is associated with enhanced disease severity in infants with severe respiratory syncytial virus bronchiolitis

BACKGROUND

Most patients with respiratory syncytial virus (RSV) bronchiolitis requiring admission to the pediatric intensive care unit (PICU) have no risk factors for severe disease. We sought to investigate the relationship between serum cytokine concentrations, innate immune responsiveness, and RSV disease severity.

METHODS

Previously healthy infants (median age, 2.6 months) with RSV bronchiolitis (PICU, n = 20; floor, n = 46) and healthy matched controls (n = 14) were enrolled, and blood samples were obtained within 24 hours of admission to measure plasma tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8), and interleukin 10 (IL-10) concentrations and, whole blood lipopolysaccharide-stimulated cytokine production capacity.

RESULTS

Plasma IL-6, IL-8, and IL-10 concentrations were comparable between PICU and floor patients, but higher than in healthy controls (P < .05). In contrast, TNF-α, IL-6, and IL-8 production capacity was significantly decreased in PICU compared with both floor patients and healthy controls. In adjusted analyses, only impaired TNF-α and IL-8 production capacity were associated with longer length of stay (P = .035) and greater disease severity scores (P = .001).

CONCLUSIONS

Infants with severe RSV bronchiolitis had increased plasma cytokine concentrations and yet impaired innate immunity cytokine production capacity, which predicted worse disease outcomes. Immune monitoring of otherwise healthy infants with RSV lower respiratory tract infection could help identify patients at risk for severe disease at the time of hospitalization.

Use of MMP-8 and MMP-9 to assess disease severity in children with viral lower respiratory tract infections

Matrix metalloproteinases (MMPs) play an important role in respiratory inflammatory diseases, such as asthma and chronic obstructive pulmonary disease. It was hypothesized that MMP-8 and MMP-9 may function as biological markers to assess disease severity in viral lower respiratory tract infections in children. MMP-8 and MMP-9 mRNA expression levels in peripheral blood mononuclear cells (PBMCs) and granulocytes obtained in both the acute and recovery phase from 153 children with mild, moderate, and severe viral lower respiratory tract infections were determined using real-time PCR. In addition, MMP-8 and MMP-9 concentrations in blood and nasopharyngeal specimens were determined during acute mild, moderate, and severe infection, and after recovery using ELISA. Furthermore, PBMCs and neutrophils obtained from healthy volunteers were stimulated with RSV, LPS (TLR4 agonist), and Pam3Cys (TLR2 agonist) in vitro. Disease severity of viral lower respiratory tract infections in children is associated with increased expression levels of the MMP-8 and MMP-9 genes in both PBMCs and granulocytes. On the contrary, in vitro experiments showed that MMP-8 and MMP-9 mRNA and protein expression in PBMCs and granulocytes is not induced by stimulation with RSV, the most frequent detected virus in young children with viral lower respiratory tract infections. These data indicate that expression levels of the MMP-8 and MMP-9 genes in both PBMCs and neutrophils are associated with viral lower respiratory tract infections disease severity. These observations justify future validation in independent prospective study cohorts of the usefulness of MMP-8 and MMP-9 as potential markers for disease severity in viral respiratory infections.

Impact on parents of bronchiolitis hospitalization of full-term, preterm and congenital heart disease infants

Background

The objective of this work was to explore the impact on parents of the bronchiolitis hospitalization of their infant using the Impact of Bronchiolitis Hospitalization Questionnaire (IBHQ©).

Methods

Four hundred sixty-three infants aged less than 1 year and hospitalized for bronchiolitis were included in a French observational study during the 2008–2009 season. Parents were asked to complete the IBHQ at hospital discharge and 3 months later. IBHQ scores, ranging from 0 (no impact) to 100 (highest impact), were compared according to gestational age (full-term, 33–36 wGA, ≤ 32 wGA) and the presence of congenital heart disease (CHD). The potential drivers of impact were explored using multivariate linear regressions.

Results

The study included 332 full-terms, 71 infants born at 33–36 wGA, and 60 at ≤ 32 wGA; 28 infants had a CHD. At hospital discharge, 9 of the 12 IBHQ mean scores were above 40, indicating a marked impact on parents. Three months later, all mean scores were lower but 5 were still greater than 40. At discharge, the length of hospitalization had a significant effect on IBHQ worries and distress, fear for future, guilt and impact on daily organization scores (p<0.01); the parents’ educational level had a significant effect on IBHQ worries and distress, fear for future, impact on daily organization and financial impact scores (p<0.05). The only statistically significant difference found between the parents of preterm and full-term infants was for the physical impact score at discharge (p=0.004).

Conclusions

Bronchiolitis hospitalization has conspicuous emotional, physical and organizational consequences on parents and siblings, which persist 3 months after hospital discharge. The main drivers of the impact were length of hospital stay and parents’ educational level, while infants’ gestational age or the presence of a CHD had little influence.

Hospitalizations for respiratory syncytial virus bronchiolitis in preterm infants at <33 weeks gestation without bronchopulmonary dysplasia: the CASTOR study

This study was conducted during the 2008–2009 respiratory syncytial virus (RSV) season in France to compare hospitalization rates for bronchiolitis (RSV-confirmed and all types) between very preterm infants (<33 weeks' gestational age, WGA) without bronchopulmonary dysplasia and full-term infants (39–41 WGA) matched for date of birth, gender and birth location, and to evaluate the country-specific risk factors for bronchiolitis hospitalization. Data on hospitalizations were collected both retrospectively and prospectively for 498 matched infants (249 per group) aged <6 months at the beginning of the RSV season. Compared to full-term infants, preterm infants had a fourfold [95% confidence interval (CI) 1·36–11·80] and a sevenfold (95% CI 2·79–17·57) higher risk of being hospitalized for bronchiolitis, RSV-confirmed and all types, respectively. Prematurity was the only factor that significantly increased the risk of being hospitalized for bronchiolitis. The risk of multiple hospitalizations for bronchiolitis in the same infant significantly increased with male gender and the presence of siblings aged ⩾2 years.

Infection with multiple viruses is not associated with increased disease severity in children with bronchiolitis

BACKGROUND

The clinical relevance of parallel detection of multiple viruses by real-time polymerase chain reaction (RT-PCR) remains unclear. This study evaluated the association between the detection of multiple viruses by RT-PCR and disease severity in children with bronchiolitis.

METHODS

Children less than 2 years of age with clinical symptoms of bronchiolitis were prospectively included during three winter seasons. Patients were categorized in three groups based on disease severity; mild (no supportive treatment), moderate (supplemental oxygen and/or nasogastric feeding), and severe (mechanical ventilation). Multiplex RT-PCR of 15 respiratory viruses was performed on nasopharyngeal aspirates.

RESULTS

In total, 142 samples were obtained. Respiratory Syncytial virus (RSV) was the most commonly detected virus (73%) followed by rhinovirus (RV) (30%). In 58 samples (41%) more than one virus was detected, of which 41% was a dual infection with RSV and RV. In RSV infected children younger than 3 months, disease severity was not associated with the number of detected viruses. Remarkably, in children older than 3 months we found an association between more severe disease and RSV mono-infections.

CONCLUSION

Disease severity in children with bronchiolitis is not associated with infection by multiple viruses. We conclude that other factors, such as age, contribute to disease severity to a larger extent.

Managing the morbidity associated with respiratory viral infections in children with congenital heart disease

Children with congenital heart disease (CHD) are at risk for increased morbidity from viral lower respiratory tract infections because of anatomical cardiac lesions than can worsen an already compromised respiratory status. Respiratory syncytial virus (RSV) remains an important pathogen in contributing toward the morbidity in this population. Although the acute treatment of RSV largely remains supportive, the development of monoclonal antibodies, such as palivuzumab, has reduced the RSV-related hospitalization rate in children with CHD. This review highlights the specific cardiac complications of RSV infection, the acute treatment of bronchiolitis in patients with CHD, and the search for new therapies against RSV, including an effective vaccine, because of the high cost associated with immunoprophylaxis and its lack of reducing RSV-related mortality.

Antibody response and avidity of respiratory syncytial virus-specific total IgG, IgG1, and IgG3 in young children

Respiratory syncytial virus (RSV) is a major cause of acute respiratory disease in infants and young children. Considering that several aspects of the humoral immune response to RSV infection remain unclear, this study aimed to investigate the occurrence, levels, and avidity of total IgG, IgG1, and IgG3 antibodies against RSV in serum samples from children ≤5 years old. In addition, a possible association between antibody avidity and severity of illness was examined. The occurrence and levels of RSV-specific IgG depended on age, with infants <3 months old displaying high levels of antibodies, which were probably acquired from the mother. Children ≥24 months old also showed frequent occurrence and high levels of IgG, which was produced actively during infection. In addition, the avidity assay showed that the avidity of RSV-specific total IgG and IgG1 was lower in infants <3 months old who had acute respiratory disease than in age-matched controls. The avidity of RSV-specific IgG detected in children ≥24 months old with lower respiratory infection was lower than that in children with upper respiratory infection. These results indicate that the presence of high avidity RSV-specific IgG antibodies may lead to better protection against RSV infection in children <3 months old, who may have a lower probability of developing disease of increased severity. In addition, children ≥24 months old with RSV-specific IgG antibodies of low avidity tended to develop more severe RSV illness. These findings may be helpful in establishing vaccination schedules when a vaccine becomes available.

The impact of prophylaxis on paediatric intensive care unit admissions for RSV infection: a retrospective, single-centre study

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections and hospitalizations in children aged < 2 years. The aim of this retrospective, single-centre study was to examine the characteristics of patients admitted to a paediatric intensive care unit (PICU) with RSV infection following the implementation of a RSV prophylaxis programme. Electronic hospital medical records of all PICU admissions for RSV infection were searched from 2003 to 2009. Data on baseline demographics, underlying disease, criteria for hospitalization, respiratory diagnosis and management, complications and palivizumab prophylaxis were collected. A total of 181 patients were admitted with RSV infection, accounting for 5.7% of all admissions. Eighty-four percent were ≤ 2 years of age. Majority (70.2%) had no underlying medical illness, and 79.6% received antibiotics as part of their medical treatment. Comparison of children aged ≤ 2 years and those >2 years revealed that fewer of the younger cohort (20.4% versus 79.3%; p < 0.001) had an underlying medical condition. RSV infection occurred in 3.3% (n = 6) children who had received palivizumab prophylaxis, and there were two deaths. The results indicate that > 88% of all PICU admissions would not qualify for RSV prophylaxis under our established guidelines and 66% of the children aged ≤ 2 years were > 36 weeks gestation and are not currently targeted for prophylaxis. The number of high-risk infants admitted to PICU with RSV infection has likely plateaued, and further reductions in admission rates may only be realised with the use of universal, vaccine immunization programmes.

Paediatric intensive care admissions for respiratory syncytial virus bronchiolitis in France: results of a retrospective survey and evaluation of the validity of a medical information system programme

The purpose of this study was to describe the characteristics of patients with bronchiolitis admitted to a paediatric intensive care unit (PICU), and to evaluate a national registry of hospitalizations (Programme de Médicalisation des Systèmes d'Information; PMSI) as a potential source of epidemiological data. Of the 49 French PICUs invited to take part in a retrospective survey of children aged <2 years who were hospitalized during the 2005–2006 epidemic season, 24 agreed to participate. Overall, 467 children were enrolled: 75% were aged <2 months, 76% had positive respiratory syncytial virus (RSV) tests, 34·9% required non-invasive ventilation, 36·6% were mechanically ventilated, and six infants died. The main neonatal characteristics were: prematurity (31·9%), respiratory disease (16·5%), congenital heart disease (6·4%), receiving mechanical ventilation (11·6%), and bronchopulmonary dysplasia at day 28 (3·8%). For bronchiolitis episode, the kappa coefficient between the survey and PMSI data was good only for mechanical ventilation (0·63) and the death rate (0·86).

Virologically confirmed population-based burden of hospitalization caused by respiratory syncytial virus, adenovirus, and parainfluenza viruses in children in Hong Kong

OBJECTIVES

To determine virologically confirmed hospitalization rates associated with respiratory syncytial virus (RSV), adenovirus, and parainfluenza viruses in Hong Kong children.

METHODS

All patients <18 years of age living on Hong Kong Island (within Hong Kong SAR) admitted for a febrile acute respiratory infection to 1 of the 2 public hospitals on 1 fixed day of the week between October 2003 and September 2006 were prospectively recruited. Hong Kong Island has a known population denominator and these 2 hospitals managed 72.5% of all general pediatric admissions for this population. Nasopharyngeal aspirates were tested for RSV, adenovirus, and parainfluenzae types 1, 2, and 3 by direct antigen detection and culture.

RESULTS

The annual hospitalization rate for RSV in infants <6 months of age was 233.4 to 311.2 per 10,000. Parainfluenza type 3 had a hospitalization rate of 27.3 to 122.8 per 10,000 in the 1 to <2 years group. Adenovirus was associated with significant hospitalization in those 6 months to 1 year (25.9-77.8 per 10,000), and in those 2 to <5 years (38.1-59.2 per 10,000). The mean duration of hospitalization for RSV was 4.04 ± 2.61 days, significantly longer than the 3.12 ± 1.41 days for adenovirus and the 2.93 ± 2.54 days for parainfluenza infections (P = 0.013 and P = 0.038, respectively).

CONCLUSION

We documented that the overall pediatric hospitalization burden of RSV was high and comparable to that of influenza. The burden for all the studied viruses was mainly in previously healthy children <5 years of age.

Community-acquired respiratory infections in young children with congenital heart diseases in the palivizumab era: the Spanish 4-season civic epidemiologic study

INTRODUCTION

To investigate the epidemiology of acute respiratory tract infections (ARIs) in children younger than 24 months old with hemodynamically significant congenital heart diseases. Primary aim: incidence of hospital admission due to ARI. Secondary aims: risk factors, etiologic agents, clinical outcomes, and usefulness of preventive measures.

PATIENTS AND METHODS

Prospective, multicenter, epidemiologic study conducted in 57 Spanish hospitals covering four 7-month seasons (2004-2008).

RESULTS

A total of 2613 patients were eligible for the study. Three hundred fifty-four patients (13.5%) (95% confidence interval: 12.3-14.9) required a total of 453 hospital admissions. Clinical diagnoses: bronchiolitis (54.1%), upper respiratory tract infection (21%), pneumonia (19.9%), and others (17.4%). Median length of hospital stay: 7.0 days. No etiologic agent was identified in two-thirds of the patients. In the remaining patients either a single agent (26.8%) or polymicrobial infection (5%) was identified. Respiratory syncytial virus (RSV) was the agent that was most commonly found (3.8% specific hospitalization rate). Children receiving adequate RSV prophylaxis (90.5%) had a 58.2% (95% confidence interval: 37.6-78.3) reduction in RSV hospitalization. Risk factors for admission included malnourishment, infant age, male gender, chromosome alterations, wheezing, inadequate RSV prophylaxis fulfillment, and siblings <11 years of age. Pediatric intensive care unit care was required in 21.8% of the admissions and 9 patients (0.34%) died.

CONCLUSIONS

Hospital admission rate and severity of ARI remain as important issues in hemodynamically significant congenital heart disease patients. The strict fulfillment of prophylactic recommendations against RSV is the only protective factor that can be modulated to decrease the ARI hospital admission rate.

Fatality rates in published reports of RSV hospitalizations among high-risk and otherwise healthy children

OBJECTIVE

To review the fatalities among children hospitalized with respiratory syncytial virus (RSV) infection, and identify factors leading to a fatal outcome.

RESEARCH DESIGN AND METHODS

Review of literature identified from a structured search of PubMed (1966-2009) using the following Medical Subject Headings: respiratory syncytial virus infection; hospitalized; infants; and risk factors. Publications were restricted to: English language; full papers; inclusion of > or =10 subjects; children aged < or =18 years, hospitalization for RSV infection; and deaths reported. Case fatality rates were defined as number of deaths divided by number of children hospitalized for RSV and were calculated for each study.

RESULTS

Thirty-six studies met the inclusion and exclusion criteria. Case fatality rates among children hospitalized for RSV ranged from 0 to 33%. In general, studies showed that subgroups of high-risk children (chronic lung disease [CLD] 3.5-23%, congenital heart disease [CHD] 2-37%, and prematurity 0-6.1%) had higher fatality rates than older or otherwise healthy children (consistently <1%). Presence of severe underlying comorbidities such as neuromuscular disease, immunosuppression, and malignancies was associated with death among term and/or older (>1 year) children. Higher fatality rates were reported for infants receiving intensive unit care (1.1-8.6%), extracorporeal life support (33%) or for those who acquired nosocomial RSV infection (0-12.2%). The majority of studies did not report cause of death and clinical details of the fatal cases were often not provided. Other limitations of this review include our search limits, the possibility of inherent bias in our methodology that could result in an under or over estimation of case-fatality rates, and potential publication bias.

CONCLUSIONS

Children at high risk for RSV (CLD, CHD and prematurity), those with severe underlying comorbidities, or those with nosocomial RSV appear to be at increased risk for death after RSV hospitalization. More data are needed on cause of death and how much is directly attributable to RSV.