Down syndrome and hospitalizations due to respiratory syncytial virus: a population-based study

Risk Factors for Poor Outcomes in Children Hospitalized With Virus-associated Acute Lower Respiratory Infections: A Systematic Review and Meta-analysis

BACKGROUND

Acute lower respiratory infection (ALRI) caused by respiratory viruses is among the most common causes of hospitalization and mortality in children. We aimed to identify risk factors for poor outcomes in children <5 years old hospitalized with ALRI caused by respiratory syncytial virus (RSV), influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We searched Embase, Medline and Global Health databases and included observational studies reporting risk factors for poor outcomes (defined as use of supplemental oxygen, mechanical ventilation, intensive care unit admission, prolonged hospital stay and mortality) published between January 2011 and January 2023. Two authors independently extracted data on study characteristics, outcomes and risk factors. Due to limited data, meta-analyses were only conducted for RSV-ALRI poor outcome risk factors using random effects model when there were at least 3 studies.

RESULTS

We included 30 studies. For RSV-related ALRI, significant risk factors based on meta-analysis were: neurological disease [odds ratio (OR): 6.14; 95% confidence intervals (CIs): 2.39-15.77], Down's syndrome (5.43; 3.02-9.76), chronic lung disease (3.64; 1.31-10.09), immunocompromised status (3.41; 1.85-6.29), prematurity (2.98; 1.93-4.59), congenital heart disease (2.80; 1.84-4.24), underlying disease (2.45; 1.94-3.09), age <2 months (2.29; 1.78-2.94), age <6 months (2.08; 1.81-2.39), viral coinfection (2.01; 1.27-3.19), low birth weight (1.88; 1.19-2.95) and being underweight (1.80; 1.38-2.35). For influenza-related ALRI, chronic conditions and age 6-24 months were identified as risk factors for poor outcomes. Cardiovascular disease, immunosuppression, chronic kidney disease, diabetes and high blood pressure were reported as risk factors for mortality due to SARS-CoV-2 associated ALRI.

CONCLUSIONS

These findings might contribute to the development of guidelines for prophylaxis and management of ALRI caused by RSV, influenza and SARS-CoV-2.

Pulmonary complications in children with Down syndrome: A scoping review

CONTEXT

Down syndrome (DS) is a prevalent chromosomal disorder associated with a wide range of congenital anomalies and other health problems.

OBJECTIVES

To give a scoping overview of encountered lower airway problems (both infectious and non-infectious) in DS children.

DATA SOURCES

We systematically searched the MEDLINE and PubMed databases for relevant publications.

STUDY SELECTION

Studies were eligible if they were original studies about pediatric airway problems in DS and were evaluated by the PRISMA guidelines.

DATA EXTRACTION

Data concerning patient characteristics, study methods and outcomes were critically reviewed.

RESULTS

Sixty papers were included. These were reviewed and summarized by topic, i.e. airway anomalies, dysphagia and aspiration, lower respiratory tract infections (and bronchiolitis in particular), pulmonary hypertension and other. Respiratory problems are proven to be a frequent and a major health burden in DS children. Airway anomalies (both single and multiple) are more prevalent and require a specific approach. A large proportion of DS children have (often silent) aspiration, resulting in protracted and difficult-to-treat symptoms. Respiratory tract infections are usually more severe and associated with an increased need for (prolonged) hospitalization. Pulmonary hypertension, wheeze and some other rare conditions are more commonly encountered in DS.

LIMITATIONS

Large number of studies and high levels of study heterogeneity.

CONCLUSIONS

Several lower airway problems are more frequent and more complex in children with DS. These findings emphasize the need for a multidisciplinary approach by an experienced team allowing for a prompt diagnosis, proper management and improved long term outcome.

Respiratory Syncytial Virus-Associated Hospitalizations in Children With Neurological Disorders, 2006-2015

BACKGROUND

We quantified the risk of respiratory syncytial virus (RSV) hospitalizations and severe outcomes among children with neurological disorders.

METHODS

We estimated RSV-specific and RSV-associated hospitalization rates using International Classification of Diseases, Ninth Revision (ICD-9) codes from 2 insurance claims IBM MarketScan Research Databases (Commercial and Multi-State Medicaid) from July 2006 through June 2015. For comparison, a simple random sample of 10% of all eligible children was selected to represent the general population. Relative rates (RRs) of RSV hospitalization were calculated by dividing rates for children with neurological disorders by rates for children in the general population by age group and season.

RESULTS

The RSV-specific hospitalization rate for children with any neurological condition was 4.2 (95% confidence interval [CI]: 4.1, 4.4) per 1000 person-years, and the RSV-associated hospitalization rate was 7.0 (95% CI: 6.9, 7.2) per 1000 person-years among children <19 years of age. Among privately insured children, the overall RR of RSV hospitalization in children with neurological disorders compared with the general population was 10.7 (95% CI: 10.0, 11.4) for RSV-specific hospitalization and 11.1 (95% CI: 10.5, 11.7) for RSV-associated hospitalizations. Among children in Medicaid, the RSV-specific hospitalization RR was 6.1 (95% CI: 5.8, 6.5) and the RSV-associated hospitalization RR was 6.4 (95% CI: 6.2, 6.7) compared with the general population.

CONCLUSIONS

Our population-based study of children with neurological disorders found that the risk of RSV hospitalization was 6 to 12 times higher among children with neurological disorders than among the general pediatric population. These findings should be considered when determining who should be targeted for current and future RSV interventions.

The Burden of Respiratory Syncytial Virus in Children Under 2 Years of Age in a Rural Community in Maharashtra, India

BACKGROUND

Globally, respiratory syncytial virus (RSV) is a common cause of acute lower tract infection (LRTI) in children younger than 2 years of age, but there are scant population-based studies on the burden of RSV illness in rural communities and no community studies in preterm infants.

METHODS

Active surveillance of LRTI was performed in the community and hospital setting for the population of 93 tribal villages in Melghat, Central India, over 4 respiratory seasons. A nasopharyngeal swab was obtained from cases presenting as a severe LRTI for molecular analysis of respiratory pathogens including RSVA and B.

RESULTS

High rates of RSV-associated LRTI were found in preterm and term infants beyond 6 months of age, extending into the second year of life. Community severe RSV LRTI rates for 0-11 months of age was 22.4 (18.6-27.0)/1000 child-years (CY) and the hospital-associated rate was 14.1 (11.1-17.8)/1000 CY. For preterm infants, these rates were 26.2 (17.8-38.5)/1000 CY and 12.6 (7.2-22.0)/1000 CY. Comparable rates in the first 6 months were 15.9 (11.8-21.4)/1000 CY and 12.9 (9.3-18.0)/1000 CY in term infants and 26.3 (15.4-45.0)/1000 CY and 10.1 (4.2-24.2)/1000 CY for preterms. The single RSV B season had higher incidences of RSV LRTI in every age group than the 2 RSV A seasons in both preterm and term infants. There were 11 deaths, all term infants.

CONCLUSIONS

Studies restricted to the healthcare settings significantly underestimate the burden of RSV LRTI and preterm and term infants have comparable burdens of disease in this rural community.

The impact of obstructive sleep apnea on bronchiolitis severity in children with Down syndrome

OBJECTIVES

Acute bronchiolitis commonly causes respiratory failure in children ≤2 years, and is particularly severe in those with Down syndrome (DS). Obstructive sleep apnea (OSA), common in DS, is also associated with respiratory complications. However, it is unknown whether OSA is associated with worse outcomes in children with and without DS, hospitalized with bronchiolitis. We hypothesized that in children with bronchiolitis, OSA is associated with worse outcomes in those with DS, independent of DS-related comorbidities.

METHODS

Hospital discharge records of children with bronchiolitis aged ≤2 years were obtained for 1997-2012 from the Kid's Inpatient Database. The primary outcome was invasive mechanical ventilation (IMV), and secondary outcomes were non-invasive mechanical ventilation (NIMV), length of hospital stay, and inflation-adjusted cost of hospitalization (IACH). Multivariable regression was conducted to ascertain the associations between OSA and primary and secondary outcomes accounting for DS-associated comorbidities.

RESULTS

There were 928,961 hospitalizations for bronchiolitis. The DS group with bronchiolitis (n = 8697) was more likely to have OSA [241 (2.77%) vs 1293 (0.14%), p < 0.001] compared to the non-DS group (n = 920,264). Multivariable logistic regression showed that OSA was associated with IMV (adjusted odds ratio [OR], 3.32 [95% CI 2.54-4.35], p < 0.0001) in all children with bronchiolitis; and in those with DS, it was associated with IMV (adjusted OR, 2.34 [95% CI 1.38-3.97], p = 0.002), NIMV (adjusted OR, 8.21 [95% CI 4.48-15.04], p < 0.0001) and IACH (adjusted β, 0.18 [95% CI 0.02-0.34], p = 0.031).

CONCLUSIONS

OSA is independently associated with assisted ventilation in all children hospitalized with bronchiolitis, regardless of DS-associated comorbidities in those with DS. The severity of bronchiolitis in children with DS may be driven by the high prevalence of OSA.

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.

COVID-19 in patients with Down syndrome

PURPOSE

The aim of the current study was to determine whether COVID-19 is associated with a different presenting clinical picture or a more severe course of illness in people with Down syndrome (DS).

METHODS

All consecutive patients who were admitted at healthcare facilities anywhere in Fars province (located in the south of Iran with a population of 4,851,000 people) from 19 February 2020 to 20 November 2020 were included. For every patient with DS, three age- and sex-matched patients with COVID-19 and without any underlying medical conditions were selected as controls.

RESULTS

During the study period, 37,968 patients were hospitalized with a diagnosis of COVID-19. Eighteen patients had DS. Patients with DS were significantly more likely to be intubated [7 patients (39%)] compared with those without DS [3 patients (6%)]; p = 0.002. Patients with DS significantly more often died of COVID-19 compared with the controls [8 (44.4%) vs. 1 (1.9%); odds ratio: 24.37; 95% confidence interval 2.39-247.94; p = 0.007].

CONCLUSION

Patients with DS are among the high-risk populations with respect to severe COVID-19 and should receive the vaccine as soon as possible. Furthermore, they should receive more intensive care if they get hospitalized with the illness.

Pneumonia and respiratory infections in Down syndrome: A scoping review of the literature

Pneumonia and respiratory infections impact infants and children with Down syndrome; pneumonia is a leading cause of mortality in adults with Down syndrome. We aimed to review the literature to evaluate gaps and address key questions. A series of key questions were formulated a priori to inform the search strategy and review process; addressed prevalence, severity, etiology, risk factors, preventive methods, screening, and financial costs, potential benefits or harms of screening. Using the National Library of Medicine database, PubMed, detailed literature searches on pneumonia and respiratory infections in Down syndrome were performed. Previously identified review articles were also assessed. The quality of available evidence was then evaluated and knowledge gaps were identified. Forty-two relevant original articles were identified which addressed at least one key question. Study details including research design, internal validity, external validity, and relevant results are presented. Pneumonia and respiratory infections are more prevalent and more severe in individuals with Down syndrome compared to healthy controls through literature review, yet there are gaps in the literature regarding the etiology of pneumonia, the infectious organism, risk factors for infection, and to guide options for prevention and screening. There is urgent need for additional research studies in Down syndrome, especially in the time of the current COVID-19 pandemic.

Respiratory Syncytial Virus-related Death in Children With Down Syndrome: The RSV GOLD Study

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of mortality in children younger than 5 years worldwide. Systematic reviews have shown that Down syndrome (DS) is an independent risk factor for severe RSV infection. We aimed to describe demographic and clinical characteristics of children with DS who died with RSV infection.

METHODS

We performed a retrospective case series in which data were shared by individual researchers, research networks and physicians worldwide as part of the RSV Global Online Database study. We included children with DS who died when younger than 5 years of age with laboratory-confirmed RSV infection.

RESULTS

We included 53 children with DS and RSV-related mortality from 20 countries in 5 continents. Five (9.4%) children were from low-income or lower-middle-income countries. Median age at time of death was 6.0 months [interquartile range (IQR): 3.00-12.0]. Thirteen (24.5%) children were born term and had no other risk factors for severe RSV disease. In total, 36 (67.9%) children had congenital heart disease, 8 (15.1%) had chronic lung disease and 1 (1.9%) had congenital immunodeficiency. Duration of hospitalization was significantly longer for children with DS compared with children without DS [median length of stay, 13 days (IQR: 6.8-21.0) vs. 8 days (IQR: 3.0-18.5), P=0.005].

CONCLUSIONS

One-fourth of children with DS and RSV-confirmed death did not have risk factors for severe RSV disease, indicating that DS is an important risk factor for RSV-related mortality. Age distribution at time of death demonstrates that maternal vaccination would not be sufficient to protect children with DS against RSV-related mortality.

Epidemiology, clinical features, and resource utilization associated with respiratory syncytial virus in the community and hospital

BACKGROUND

The epidemiology, clinical features, and resource utilization of respiratory syncytial virus (RSV) cases in the community and the hospital are not fully characterized.

METHODS

We identified individuals of all ages with laboratory-confirmed RSV from two sources, a community cohort undergoing surveillance for acute respiratory infections (ARIs) and hospitalized patients from the same geographic area of New York City between 2013 and 15. The epidemiology, clinical features, and resource utilization (antibiotic/steroid/ribavirin usage, chest X-rays, respiratory-support (continuous positive airway pressure [CPAP], mechanical ventilation or extracorporeal membrane oxygenation [ECMO]), and indicators of disease severity (respiratory-support, and/or ICU admission or death)) were compared among age groups using univariate and bivariate analyses.

RESULTS

In the community cohort (1777 people with 1805 ARIs), 66(3.7%) tested RSV-positive (3.8% of <1-year-olds; 3.8% of adults ≥65); 40.9% were medically attended, and 23.1% reported antibiotic usage. Among 40,461 tests performed on hospital patients, 2.7% were RSV-positive within ± 2 days of admission (37.3% <1 year old; 17.4% ≥65 years old). Among RSV-positive hospitalized adults ≥65%, 92.7%, 89.6% and 78.1% received a chest X-ray, antibiotics and/or steroids respectively, compared with 48.9%, 45.7%, and 48.7% of children <1. Severe illness occurred in 27.0% RSV-positive hospitalized <1-year-olds and 19.8% ≥65-year-olds.

CONCLUSIONS

Respiratory syncytial virus had a demonstrated impact in the community and hospital. Only 40% of RSV community cases were medically attended. In the hospitalized-cohort, <1- and ≥ 65-year-olds accounted for the majority of patients and had similar rates of severe illness. In addition, resource utilization was high in older adults, making both young children and older adults important potential RSV vaccine targets.

Respiratory syncytial virus infection: why does disease severity vary among individuals?

Introduction: Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory tract infections in infancy. While many infants are infected with RSV, the nature and severity of the disease vary among individuals. RSV causes bronchiolitis, pneumonia, and asthma exacerbation. However, most children infected with RSV have only mild upper airways disease and may be asymptomatic.Areas covered: Despite efforts to elucidate mechanisms for the various clinical responses to RSV infection, they remain largely unknown, suggesting that susceptibility and disease are influenced by multiple intrinsic and extrinsic factors. This article reviews the available literature on the field of RSV disease severity and discusses important factors associated to susceptibility and different disease outcome.Expert opinion: The severity of RSV-induced illness is a phenomenon that depends on a variety of graded mechanisms of interaction between the host, virus, and environment. This may lead to differences in the intensity of immune response in the lung and different courses of the disease. By characterizing, classifying, and grading the affecting factors in high-risk patients versus those who do not fall ill by RSV, we may find therapies or point to disease-limiting medications.

Hospitalization for Respiratory Syncytial Virus in Children with Down Syndrome Less than 2 Years of Age: A Systematic Review and Meta-Analysis

OBJECTIVES

To compare the respiratory syncytial virus (RSV)-related hospitalization rate, hospital length of stay (LOS), and need for assisted ventilation in children aged <2 years with Down syndrome and those without Down syndrome.

STUDY DESIGN

MEDLINE, Embase, and CINAHL databases were searched from inception up to December 2017. Studies that provided data on RSV-related hospitalization in children aged <2 years with Down syndrome and those without Down syndrome were included. Data were independently extracted in pairs by 2 reviewers and synthesized with random-effects meta-analysis.

RESULTS

In 10 studies including a total of 1 748 209 children, 12.6% of the children with Down syndrome (491 of 3882) were hospitalized with RSV infection. The presence of Down syndrome was associated with a significantly higher risk of RSV-related hospitalization (relative risk [RR], 6.06; 95% CI, 4.93-7.45; I² = 65%; Grading of Recommendations, Assessment, Development and Evaluation [GRADE], moderate). RSV-related LOS (mean difference, 2.11 days; 95% CI, 1.47-2.75 days; I² = 0%; GRADE, low), and the need for assisted ventilation (RR, 5.82; 95% CI, 1.81-18.69; I² = 84%; GRADE, low). Children with Down syndrome without congenital heart disease (RR, 6.31; 95% CI, 4.83-8.23; GRADE, moderate) also had a significantly higher risk of RSV-related hospitalization. The risk of RSV-related hospitalization remained significant in the subgroup of children aged <1 year (RR, 6.25; 95% CI, 4.71-8.28; GRADE, high).

CONCLUSION

RSV-related hospitalization, hospital LOS, and the need for assisted ventilation are significantly higher in children with Down syndrome aged <2 years compared with those without Down syndrome. The results should prompt reconsideration of the need for routine RSV prophylaxis in children with Down syndrome up to 2 years of age.

Respiratory syncytial virus prophylaxis and the "special population"

Bronchiolitis is the most frequent airway infection in the first 2 years of life, and the respiratory syncytial virus (RSV) is the most frequently responsible virus. In selected high-risk groups, RSV may cause severe respiratory disease leading to hospitalization, need for mechanical ventilation, and even death. These high-risk groups include children with congenital heart disease, infants with neuromuscular impairment, cystic fibrosis, Down Syndrome, immunodeficiency syndromes and others specific conditions. In these high-risk populations defined in literature as "special population", a 3- to 10-fold increase in the rate of RSV hospitalization has been observed, justifying RSV specific prophylaxis with palivizumab, a monoclonal antibody that binds a viral glycoprotein epitope and blocks the link between RSV and target cell. Evidence of safety and efficacy of RSV prophylaxis in these populations is lacking. Given the low incidence of these conditions, randomized clinical trials are not feasible. The purpose of this paper is to give an update from the literature of various conditions at higher risk to develop severe RSV infection, and to offer an overview of the efficacy of palivizumab in preventing RSV infection in these specific populations.

Down Syndrome and the Risk of Severe RSV Infection: A Meta-analysis

CONTEXT

Down syndrome (DS) is the most common chromosomal condition in live-born infants worldwide, and lower respiratory infection caused by respiratory syncytial virus (RSV) is a leading cause of hospital admissions.

OBJECTIVE

To evaluate RSV-associated morbidity among children with DS compared with a population without DS.

DATA SOURCES

Four electronic databases were searched.

STUDY SELECTION

All cohorts or case-control studies of DS with an assessment of RSV infection and the associated morbidity or mortality were included without language restriction.

DATA EXTRACTION

Two reviewers independently reviewed all studies. The primary outcomes were hospital admission and mortality. Secondary outcomes included length of hospital stay, oxygen requirement, ICU admission, need for respiratory support, and additional medication use.

RESULTS

Twelve studies (n = 1 149 171) from 10 different countries met the inclusion criteria; 10 studies were cohort studies, 1 study was retrospective, and 1 study had both designs. DS was associated with a higher risk of hospitalization (odds ratio [OR]: 8.69; 95% confidence interval [CI]: 7.33-10.30; I² = 11%) and mortality (OR: 9.4; 95% CI: 2.26-39.15; I² = 38%) compared with what was seen in controls. Children with DS had an increased length of hospital stay (mean difference: 4.73 days; 95% CI: 2.12-7.33; I² = 0%), oxygen requirement (OR: 6.53; 95% CI: 2.22-19.19; I² = 0%), ICU admission (OR: 2.56; 95% CI: 1.17-5.59; I² = 0%), need for mechanical ventilation (OR: 2.56; 95% CI: 1.17-5.59; I² = 0%), and additional medication use (OR: 2.65 [95% CI: 1.38-5.08; I² = 0%] for systemic corticosteroids and OR: 5.82 [95% CI: 2.66-12.69; I² = 0%] for antibiotics) than controls.

LIMITATIONS

DS subgroups with and without other additional risk factors were not reported in all of the included studies.

CONCLUSIONS

Children with DS had a significantly higher risk of severe RSV infection than children without DS.

Palivizumab use in infants with Down syndrome-report from the German Synagis™ Registry 2009-2016

Infants with Down syndrome (DS) face an increased risk of respiratory tract infections. Recent studies describe DS as independent risk factor for a complicated clinical course in infants with respiratory syncytial virus (RSV) infection. The prospective observational German Synagis™ Registry comprises data from 249 children below 25 months of age with DS and palivizumab prophylaxis 2009-2016 (1191 administrations; mean 4.8 per patient and season). The median gestational age and the birth weight in patients without and with DS were 31 versus 37 weeks (P < 0.001) and 1590 versus 2750 g, respectively (P < 0.001). Patients with DS significantly more often had congenital heart disease (CHD), siblings in kindergarten or school, treatment with oxygen at home, immunodeficiency, and neuromuscular impairment. The RSV-related hospitalization rate in patients with DS was 1.20%; the hospitalization rate in patients without DS was 0.71%.

CONCLUSION

Data from 249 children with DS receiving palivizumab prophylaxis in seven consecutive RSV seasons (2009-2016) in Germany reveal important differences between patients with and without DS concerning the main indication for palivizumab use and additional risk factors. Bearing in mind the limitations of an uncontrolled postmarketing observational study, the results confirm the field effectiveness of palivizumab prophylaxis in this special population. What is Known: • Recent studies describe the Down syndrome as independent risk factor for a complicated clinical course in infants with RSV infection. What is New: • Compared with other infants receiving palivizumab prophylaxis, patients with Down syndrome significantly more often had congenital heart disease, siblings in kindergarten or school, treatment with oxygen at home, immunodeficiency, and neuromuscular impairment. • In infants with palivizumab prophylaxis breakthrough, RSV-related hospitalization rates were not significantly higher in those with Down syndrome.

The burden of respiratory syncytial virus (RSV) associated acute lower respiratory infections in children with Down syndrome: A systematic review and meta-analysis

Background

Acute lower respiratory tract infections (ALRIs) caused by respiratory syncytial virus (RSV) are a leading cause of hospitalization in infants. Numerous risk factors have been identified in the aetiology of severe RSV–associated ALRI necessitating hospitalisation, including prematurity and congenital heart disease. Down syndrome (DS), a common genetic disorder associated with congenital and dysmorphic features, has recently been identified as an independent risk factor for RSV–associated ALRI requiring hospitalisation; however, the disease burden of RSV–associated ALRI in this population has not yet been established. Similarly, the impact of DS as an independent risk factor has not yet been quantified. We aimed therefore to estimate the incidence of admissions in children with DS, and by comparing this with unaffected children, to quantify the risk of DS independent of other risk factors.

Methods

A systematic review of the existing literature published between 1995 and March 1, 2017 was performed to quantify the incidence of hospitalisation due to RSV–associated ALRI in children with DS. Meta–analyses were performed on extracted data using STATA statistical software, and hospitalisation rates for children with and without DS under the age of 2 were calculated.

Findings

5 articles were ultimately deemed eligible for analyses. Analyses were limited to children under the age of 2 years. We calculated the hospitalisation rate for children with DS in this age group to be 117.6 per 1000 child–years (95% CI 67.4–205.2), vs a rate of 15.2 per 1000 child–years (95% CI 8.3–27.6) in unaffected children. This indicates DS contributes to a 6.8 (95% CI 5.5–8.4) fold increase in the relative risk of hospitalisation for RSV–associated ALRI.

Interpretation

Though limited by a small number of articles, this review found sufficient evidence to conclude DS was a significant independent risk factor for the development of severe RSV–associated ALRI requiring hospitalisation. Further studies are needed to define the impact of DS in conjunction with other comorbidities on the risk of severe RSV infection. Determining benefits of immunoprophylaxis or future vaccines against RSV in this at–risk population is warranted.

Past, Present and Future Approaches to the Prevention and Treatment of Respiratory Syncytial Virus Infection in Children

INTRODUCTION

The REGAL (RSV Evidence - A Geographical Archive of the Literature) series has provided a comprehensive review of the published evidence in the field of respiratory syncytial virus (RSV) in Western countries over the last 20 years. This seventh and final publication covers the past, present and future approaches to the prevention and treatment of RSV infection among infants and children.

METHODS

A systematic review was undertaken of publications between January 1, 1995 and December 31, 2017 across PubMed, Embase and The Cochrane Library. Studies reporting data on the effectiveness and tolerability of prophylactic and therapeutic agents for RSV infection were included. Study quality and strength of evidence (SOE) were graded using recognized criteria. A further nonsystematic search of the published literature and Clinicaltrials.gov on antiviral therapies and RSV vaccines currently in development was also undertaken.

RESULTS

The systematic review identified 1441 studies of which 161 were included. Management of RSV remains centered around prophylaxis with the monoclonal antibody palivizumab, which has proven effective in reducing RSV hospitalization (RSVH) in preterm infants < 36 weeks' gestational age (72% reduction), children with bronchopulmonary dysplasia (65% reduction), and infants with hemodynamically significant congenital heart disease (53% reduction) (high SOE). Palivizumab has also shown to be effective in reducing recurrent wheezing following RSVH (high SOE). Treatment of RSV with ribavirin has conflicting success (moderate SOE). Antibodies with increased potency and extended half-life are currently entering phase 3 trials. There are approximately 15 RSV vaccines in clinical development targeting the infant directly or indirectly via the mother.

CONCLUSION

Palivizumab remains the only product licensed for RSV prophylaxis, and only available for high-risk infants. For the general population, there are several promising vaccines and monoclonal antibodies in various stages of clinical development, with the aim to significantly reduce the global healthcare impact of this common viral infection.

FUNDING

AbbVie.

Patient safety vulnerabilities for children with intellectual disability in hospital: a systematic review and narrative synthesis

PURPOSE

Adults and children with intellectual disability (ID) are vulnerable to preventable morbidity and mortality due to poor quality healthcare. While poor quality care has been commonly identified among children with ID, evidence of the patient safety outcomes for this group is lacking and therefore explored in this review.

DATA SOURCES

Systematic searches of six electronic bibliographic research databases were undertaken from January 2000 to October 2017, in addition to hand searching.

STUDY SELECTION

Keywords, subject headings and MeSH terms relating to the experience of iatrogenic harm during hospitalisation for children with ID were used. Potentially relevant articles were screened against the eligibility criteria. Non-English language papers were excluded.

DATA EXTRACTION

Data regarding: author(s), publication year, country, sample, health service setting, study design, primary focus and main findings related to measures of quality and safety performance were extracted.

RESULTS OF DATA SYNTHESIS

Sixteen studies met the inclusion criteria, with three themes emerging: the impact of the assumptions of healthcare workers (HCWs) about the child with ID on care quality and associated safety outcomes; reliance on parental presence during hospitalisation as a protective factor; and the need for HCWs to possess comprehensive understanding of the IDs experienced by children in their care, to scientifically deduce how hospitalisation may compromise their safety, care quality and treatment outcomes.

CONCLUSION

When HCWs understand and are responsive to children's individual needs and their ID, they are better placed to adjust care delivery processes to improve care quality and safety during hospitalisation for children with ID.

Defining the Incidence and Associated Morbidity and Mortality of Severe Respiratory Syncytial Virus Infection Among Children with Chronic Diseases

INTRODUCTION

REGAL (RSV Evidence-a Geographical Archive of the Literature) has provided a comprehensive review of the published evidence in the field of respiratory syncytial virus (RSV) in Western countries over the last 20 years. This review covers the risk and burden of RSV infection in children with underlying medical conditions or chronic diseases (excluding prematurity and congenital heart disease).

METHODS

A systematic review of publications between January 1, 1995 and December 31, 2015 across PubMed, Embase, The Cochrane Library, and Clinicaltrials.gov was supplemented by papers identified by the authors through March 2017. Studies reporting data for hospital visits/admissions for RSV infection as well as studies reporting RSV-associated morbidity and mortality were included. Study quality and strength of evidence (SOE) were graded.

RESULTS

A total of 2703 studies were identified and 58 were included. Down syndrome, irrespective of prematurity and congenital heart disease (moderate SOE), immunocompromised children (low SOE), cystic fibrosis (low SOE), and neurologic conditions (low SOE) were associated with a significantly increased risk of RSV hospitalization. A number of other congenital malformations and chronic conditions were also associated with severe RSV disease (low SOE). In general, pre-existing disease was also a predisposing factor for RSV-related mortality (low SOE).

CONCLUSION

Severe RSV infection in infants and young children with underlying medical conditions or chronic diseases poses a significant health burden. Further studies are needed to fully quantify the epidemiology, burden and outcomes in these populations, in particular RSV-attributable mortality.

National cohort study showed that infants with Down's syndrome faced a high risk of hospitalisation for the respiratory syncytial virus

AIM

The respiratory syncytial virus (RSV) is a leading cause of hospitalisation in infants. We investigated this risk in children with Down's syndrome under two years of age, adjusted for other known risk factors.

METHODS

This national, retrospective 1:2 matched cohort study comprised all Swedish children born with Down's from 2006 to 2011, who were each randomly matched to two controls without Down's. Data on RSV hospitalisation and risk factors for RSV were obtained from national registers. The risk of RSV hospitalisation was assessed using multivariable Cox regression with pairwise stratification.

RESULTS

The study comprised 814 children with Down's and 1628 controls. We found that 82 children with Down's (10.1%) and 22 controls (1.4%) were hospitalised for RSV. The hazard ratio for children with Down's was 4.00 (95% confidence interval 1.58-10.13) for up to one year of age and 6.60 (95% CI: 2.83-15.38) for up to two years of age, adjusted for other risk factors. During the second year of life, RSV hospitalisation continued for children with Down's, while it was minimal for the controls.

CONCLUSION

Children with Down's faced a high risk of RSV hospitalisation, which continued beyond the first year of age.

Quantitative, Phenotypical, and Functional Characterization of Cellular Immunity in Children and Adolescents With Down Syndrome

Background

Infections and autoimmune disorders are more frequent in Down syndrome, suggesting abnormality of adaptive immunity. Although the role of B cells and antibodies is well characterized, knowledge regarding T cells is limited.

Methods

Lymphocyte subpopulations of 40 children and adolescents with Down syndrome and 51 controls were quantified, and phenotype and functionality of antigen-specific effector T cells were analyzed with flow cytometry after polyclonal and pathogen-specific stimulation (with varicella-zoster virus [VZV] and cytomegalovirus [CMV]). Results were correlated with immunoglobulin (Ig) G responses.

Results

Apart from general alterations in the percentage of lymphocytes, regulatory T cells, and T-helper 1 and 17 cells, all major T-cell subpopulations showed higher expression of the inhibitory receptor PD-1. Polyclonally stimulated effector CD4+ T-cell frequencies were significantly higher in subjects with Down syndrome, whereas their inhibitory receptor expression (programmed cell death 1 [PD-1] and cytotoxic T-lymphocyte antigen 4 [CTLA-4]) was similar to that of controls and cytokine expression profiles were only marginally altered. Pathogen-specific immunity showed age-appropriate levels of endemic infection, with correlation of CMV-specific cellular and humoral immunity in all subjects. Among VZV IgG-positive individuals, a higher percentage of VZV-specific T-cell-positive subjects was seen in those with Down syndrome.

Conclusions

Despite alterations in lymphocyte subpopulations, individuals with Down syndrome can mount effector T-cell responses with similar phenotype and functionality as controls but may require higher effector T-cell frequencies to ensure pathogen control.

Down syndrome as risk factor for respiratory syncytial virus hospitalization: A prospective multicenter epidemiological study

BACKGROUND

Respiratory syncytial virus (RSV) infection in childhood, particularly in premature infants, is associated with significant morbidity and mortality.

OBJECTIVES

To compare the hospitalization rates due to RSV infection and severity of disease between infants with and without Down syndrome (DS) born at term and without other associated risk factors for severe RSV infection.

PATIENTS/METHODS

In a prospective multicentre epidemiological study, 93 infants were included in the DS cohort and 68 matched by sex and data of birth (±1 week) and were followed up to 1 year of age and during a complete RSV season.

RESULTS

The hospitalization rate for all acute respiratory infection was significantly higher in the DS cohort than in the non-DS cohort (44.1% vs 7.7%, P<.0001). Hospitalizations due to RSV were significantly more frequent in the DH cohort than in the non-DS cohort (9.7% vs 1.5%, P=.03). RSV prophylaxis was recorded in 33 (35.5%) infants with DS. The rate of hospitalization according to presence or absence of RSV immunoprophylaxis was 3.0% vs 15%, respectively.

CONCLUSIONS

Infants with DS showed a higher rate of hospitalization due to acute lower respiratory tract infection and RSV infection compared to non-DS infants. Including DS infants in recommendations for immunoprophylaxis of RSV disease should be considered.

Fatal varicella pneumonia in an unvaccinated child with Down Syndrome: a case report

Background

Varicella is an acute infectious disease common during childhood. It has mostly an uncomplicated course in early childhood. Neverthless, it may result in severe complications, especially in particular age groups and clinical conditions. Down Syndrome represents a risk factor for developing complications, because of the frequent comorbidities and their immunodeficiency.

Case presentation

A 2-year-old white Caucasian female affected by Down Syndrome was referred to our hospital for cardiac arrest in course of varicella disease. After cardiopulmonary resuscitation and stabilization, her clinical conditions didn’t improve and she developed a massive pulmonary hemorrage, which led her to exitus.

Conclusions

Mortality due to varicella infection is rare, but it is more common in subjects with immune deficit or chronic pathologies, and in particular age-groups. The importance of the vaccine for preventable infectious diseases is stressed in this paper, in which we present a case of death in an unvaccinated cardiopathic child with Down Syndrome affected by varicella.

Down's syndrome is a risk factor for severe lower respiratory tract infection due to respiratory syncytial virus

AIM

Previous studies have suggested that Down's syndrome is an independent risk factor for severe respiratory infection due to respiratory syncytial virus (RSV). We compared the clinical characteristics of children with and without Down's syndrome hospitalised due to RSV.

METHODS

This retrospective cohort study compared data from hospitalisations due to RSV lower respiratory tract infections (LRTI) in children under 14 years of age with (n = 58) and without (n = 58) Down's syndrome.

RESULTS

The Down's group had longer hospital stays than the controls of six versus four days (p < 0.0001), even after adjusting for age, weeks of gestation at birth, presence of asthma, bronchopulmonary dysplasia, haemodynamically significant and nonsignificant congenital heart disease. This difference increased when only children under one year of age were analysed to 11 versus five days (p < 0.0001). Children with Down's syndrome were more likely to be admitted to intensive care unit (43.1% versus 22.4%, p = 0.017), need noninvasive mechanical ventilation (36.2% versus 13.7%, p = 0.005) and be prescribed antibiotics and steroids.

CONCLUSION

Children with Down's syndrome hospitalised due to RSV LRTI had longer hospital stays and worse clinical courses than controls, highlighting the need for RSV prophylaxis for children with Down's syndrome, especially under one year of age.

Trends in Respiratory Syncytial Virus and Bronchiolitis Hospitalization Rates in High-Risk Infants in a United States Nationally Representative Database, 1997-2012

BACKGROUND

Respiratory syncytial virus (RSV) causes significant pediatric morbidity and is the most common cause of bronchiolitis. Bronchiolitis hospitalizations declined among US infants from 2000‒2009; however, rates in infants at high risk for RSV have not been described. This study examined RSV and unspecified bronchiolitis (UB) hospitalization rates from 1997‒2012 among US high-risk infants.

METHODS

The Kids' Inpatient Database (KID) infant annual RSV (ICD-9 079.6, 466.11, 480.1) and UB (ICD-9 466.19, 466.1) hospitalization rates were estimated using weighted counts. Denominators were based on birth hospitalizations with conditions associated with high-risk for RSV: chronic perinatal respiratory disease (chronic lung disease [CLD]); congenital airway anomalies (CAA); congenital heart disease (CHD); Down syndrome (DS); and other genetic, metabolic, musculoskeletal, and immunodeficiency conditions. Preterm infants could not be identified. Hospitalizations were characterized by mechanical ventilation, inpatient mortality, length of stay, and total cost (2015$). Poisson and linear regression were used to test statistical significance of trends.

RESULTS

RSV and UB hospitalization rates were substantially elevated for infants with higher-risk CHD, CLD, CAA and DS without CHD compared with all infants. RSV rates declined by 47.0% in CLD and 49.7% in higher-risk CHD infants; no other declines in high-risk groups were observed. UB rates increased in all high-risk groups except for a 22.5% decrease among higher-risk CHD. Among high-risk infants, mechanical ventilation increased through 2012 to 20.4% and 13.5% of RSV and UB hospitalizations; geometric mean cost increased to $31,742 and $25,962, respectively, and RSV mortality declined to 0.9%.

CONCLUSIONS

Among high-risk infants between 1997 and 2012, RSV hospitalization rates declined among CLD and higher-risk CHD infants, coincident with widespread RSV immunoprophylaxis use in these populations. UB hospitalization rates increased in all high-risk groups except higher-risk CHD, suggesting improvement in the health status of higher-risk CHD infants, potentially due to enhanced surgical interventions. Mechanical ventilation use and RSV and UB hospitalization costs increased while RSV mortality declined.

Revised recommendations concerning palivizumab prophylaxis for respiratory syncytial virus (RSV)

Respiratory Syncytial Virus infections are one of the leading causes of severe respiratory diseases that require hospitalization and, in some cases, intensive care. Once resolved, there may be respiratory sequelae of varying severity. The lack of effective treatments for bronchiolitis and the lack of vaccines for RSV accentuate the role of prevention in decreasing the impact of this disease. Prevention of bronchiolitis strongly relies on the adoption of environment and the hygienic behavior measures; an additional prophylactic effect may be offered, in selected cases, by Palivizumab, a humanized monoclonal antibody produced by recombinant DNA technology, able to prevent RSV infection by blocking viral replication.After many years the Italian Society of Neonatology, on the basis of the most recent scientific knowledge, has decided to revise recommendations for the use of palivizumab in the prevention of RSV infection.

Down syndrome increases hospital length of stay in children with bronchiolitis

Background:

Children with Down syndrome have an increased burden of respiratory infections. We hypothesized that children with Down syndrome hospitalized for bronchiolitis would stay longer compared with children without Down syndrome.

Methods:

We conducted a retrospective case–control study of children with Down syndrome who were hospitalized for bronchiolitis in Singapore from 2004 to 2012.

Results:

There were 27 and 43 admissions in the Down syndrome and control groups respectively. More children with Down syndrome had congenital heart defects (14 (52%) vs. none in controls). Children with Down syndrome stayed longer in hospital compared with controls (7 (interquartile range (IQR) 5–14) vs. 3 (IQR 2–4) days, p<0.001). In a subgroup analysis of patients without or surgically corrected congenital heart defects, children with Down syndrome still had a longer stay (6 (IQR 5–8) vs. 3 (IQR 2–4) days, p<0.001).

Conclusion:

Our study suggests that children with Down syndrome hospitalized for bronchiolitis stayed longer in hospital compared with those without Down syndrome.

Poor outcome of acute respiratory infection in young children with underlying health condition in Brazil

Objectives

It is well established that respiratory viruses are an important cause of hospitalizations in young children worldwide, but data are limited on the contribution of specific viruses to severe illness in South America. We describe clinical and laboratory findings from prospective surveillance for acute respiratory infections at a tertiary hospital in São Paulo, Brazil.

Methods

We screened children < 2 years old with acute respiratory tract infections admitted to an urban tertiary hospital for respiratory viruses from March 2008 through February 2010, using polymerase chain reaction assays.

Results

Respiratory viruses were identified in 378 (53%) of the 715 samples analyzed. Respiratory syncytial virus was the most commonly identified virus (52%), followed by adenovirus (27%) and Human metapneumovirus (12%). More than one virus was identified in 19% of specimens. Almost half of the samples (46%) were from children with underlying health conditions. We demonstrated that compared to the previously healthy group, those with comorbidities had a worse outcome in terms of severity, with prolonged hospital stay and more need of intensive care.

Conclusion

Identification of this high-risk population along with strategies for fast diagnosis might each help to reduce morbidity and mortality in this group.

Children with Down syndrome are high-risk for severe respiratory syncytial virus disease

OBJECTIVE

To assess Down syndrome as an independent risk factor for respiratory syncytial virus (RSV) hospitalization in children younger than 3 years of age and to evaluate illness severity.

STUDY DESIGN

A retrospective cohort study of children enrolled in the military health system database was conducted. The effect of Down syndrome on RSV hospitalization was assessed by Cox proportional hazards model, while we controlled for risk factors. Disease severity was assessed by length of hospital stay, need for respiratory support, and age at hospitalization.

RESULTS

The study included 633 200 children and 3 209 378 person-years. Children with Down syndrome had a hospitalization rate of 9.6% vs 2.8% in children without Down syndrome. Down syndrome had a greater adjusted hazard ratio (HR) for RSV hospitalization than most risk factors, 3.46 (95% CI 2.75-4.37). A sensitivity analysis demonstrated HR 3.21 (95% CI 2.51-4.10) for patients with Down syndrome ages 0-23 months and HR 5.07 (95% CI 2.21-11.59) ages 24-36 months. The median (IQR) length of stay of children with and without Down syndrome was 4 days (2-7) and 2 days (1-4) (P < .001). Patients with Down syndrome had a greater risk of requiring respiratory support (relative risk 5.5; 95% CI, 2.5-12.3). The median (IQR) ages at admission for children with and without Down syndrome were 9.8 months (5.5-17.7) and 3.5 months (1.7-8.7) (P < .001).

CONCLUSIONS

Down syndrome is independently associated with an increased risk for RSV hospitalization. Children with Down syndrome are older at time of RSV hospitalization and have more severe RSV illness than children without Down syndrome. This increased risk for hospitalization continues beyond 24 months.

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.

Inter-society consensus document on treatment and prevention of bronchiolitis in newborns and infants

Acute bronchiolitis is the leading cause of lower respiratory tract infection and hospitalization in children less than 1 year of age worldwide. It is usually a mild disease, but some children may develop severe symptoms, requiring hospital admission and ventilatory support in the ICU. Infants with pre-existing risk factors (prematurity, bronchopulmonary dysplasia, congenital heart diseases and immunodeficiency) may be predisposed to a severe form of the disease. Clinical diagnosis of bronchiolitis is manly based on medical history and physical examination (rhinorrhea, cough, crackles, wheezing and signs of respiratory distress). Etiological diagnosis, with antigen or genome detection to identify viruses involved, may have a role in reducing hospital transmission of the infection. Criteria for hospitalization include low oxygen saturation (<90-92%), moderate-to-severe respiratory distress, dehydration and presence of apnea. Children with pre-existing risk factors should be carefully assessed.To date, there is no specific treatment for viral bronchiolitis, and the mainstay of therapy is supportive care. This consists of nasal suctioning and nebulized 3% hypertonic saline, assisted feeding and hydration, humidified O2 delivery. The possible role of any pharmacological approach is still debated, and till now there is no evidence to support the use of bronchodilators, corticosteroids, chest physiotherapy, antibiotics or antivirals. Nebulized adrenaline may be sometimes useful in the emergency room. Nebulized adrenaline can be useful in the hospital setting for treatment as needed. Lacking a specific etiological treatment, prophylaxis and prevention, especially in children at high risk of severe infection, have a fundamental role. Environmental preventive measures minimize viral transmission in hospital, in the outpatient setting and at home. Pharmacological prophylaxis with palivizumab for RSV bronchiolitis is indicated in specific categories of children at risk during the epidemic period. Viral bronchiolitis, especially in the case of severe form, may correlate with an increased incidence of recurrent wheezing in pre-schooled children and with asthma at school age.The aim of this document is to provide a multidisciplinary update on the current recommendations for the management and prevention of bronchiolitis, in order to share useful indications, identify gaps in knowledge and drive future research.

Updated guidance for palivizumab prophylaxis among infants and young children at increased risk of hospitalization for respiratory syncytial virus infection

Guidance from the American Academy of Pediatrics (AAP) for the use of palivizumab prophylaxis against respiratory syncytial virus (RSV) was first published in a policy statement in 1998. Guidance initially was based on the result from a single randomized, placebo-controlled clinical trial conducted in 1996-1997 describing an overall reduction in RSV hospitalization rate from 10.6% among placebo recipients to 4.8% among children who received prophylaxis. The results of a second randomized, placebo-controlled trial of children with hemodynamically significant heart disease were published in 2003 and revealed a reduction in RSV hospitalization rate from 9.7% in control subjects to 5.3% among prophylaxis recipients. Because no additional controlled trials regarding efficacy were published, AAP guidance has been updated periodically to reflect the most recent literature regarding children at greatest risk of severe disease. Since the last update in 2012, new data have become available regarding the seasonality of RSV circulation, palivizumab pharmacokinetics, the changing incidence of bronchiolitis hospitalizations, the effects of gestational age and other risk factors on RSV hospitalization rates, the mortality of children hospitalized with RSV infection, and the effect of prophylaxis on wheezing and palivizumab-resistant RSV isolates. These data enable further refinement of AAP guidance to most clearly focus on those children at greatest risk.

Probiotic-associated aspiration pneumonia due to Lactobacillus rhamnosus

Lactobacilli are low-virulence, commensal organisms of the gastrointestinal and genitourinary tracts and are commonly used as "probiotic supplements." Herein, we describe an episode of respiratory syncytial virus (RSV) bronchiolitis with bacterial superinfection secondary to administration of Lactobacillus rhamnosus in an 11-month-old female with trisomy 21.

Respiratory syncytial virus prophylaxis in Down syndrome: a prospective cohort study

BACKGROUND AND OBJECTIVES

Children with Down syndrome (DS) are at significant risk for respiratory syncytial virus (RSV) infection and related hospitalization. We compared hospitalization rates due to respiratory tract infection in children with DS aged <2 years who prospectively received palivizumab during the RSV season with a previously published, similar untreated DS birth cohort.

METHODS

A total of 532 children with DS who prospectively received palivizumab were assembled from the prospective Canadian RSV Evaluation Study of Palivizumab registry between 2005 and 2012. The untreated group included 233 children with DS derived from a nationwide Dutch birth cohort from 2003 to 2005. Events during the RSV seasons were counted. Poisson regression analysis was performed to compare incidence rate ratios (95% confidence intervals [CIs]) between groups while controlling for observation length and known risk factors for severe RSV infection.

RESULTS

In total, 31 (23 untreated, 8 treated) RSV-related hospitalizations were documented. The adjusted risk of RSV-related hospitalizations was higher in untreated subjects than in palivizumab recipients (incidence rate ratio 3.63; 95% CI, 1.52-8.67). The adjusted risk of hospitalization for all respiratory tract infection (147 events; 73 untreated, 74 treated) was similar (incidence rate ratio untreated versus palivizumab 1.11; 95% CI, 0.80-1.55).

CONCLUSIONS

These results suggest that palivizumab is associated with a 3.6-fold reduction in the incidence rate ratio for RSV-related hospitalization in children with DS during the first 2 years of life. A randomized trial is needed to determine the efficacy of RSV immunoprophylaxis in this specific high-risk patient population.

Clinical characteristics of pulmonary arterial hypertension associated with Down syndrome

The genetic abnormalities associated with Down syndrome (DS) are still being identified. Few studies have examined the roles of CRELD1 and GATA4 in cardiac abnormalities or their association with pulmonary artery histopathology. Children with DS have an elevated risk of pulmonary arterial hypertension (PAH). This increased risk is likely mainly due to genetic background, the structural characteristics of the pulmonary vascular wall, and certain heart diseases and partly due to pulmonary hypoplasia, upper and lower airway obstructive diseases, chronic infection, and neuromuscular underdevelopment. Exposure to increased left-to-right shunt flow increases sheer stress on endothelium and may induce endothelial dysfunction followed by irreversible remodeling of pulmonary arteries. Pathologic changes include endothelial cell proliferation and thickening of the pulmonary arterial wall due to mechanical responses to the thinner medial smooth muscle cell layer, which includes underdevelopment of alveoli. Production of prostacyclin and nitric oxide is diminished in DS, but endothelin-1 and thromboxane are elevated. Perioperatively, patients with DS may experience pulmonary hypertensive crisis after intracardiac repair and prolonged PAH, and have a poorer response to nitric oxide inhalation. To better manage DS, it is crucial to systematically evaluate the systemic complications of DS. Cardiac catheterization data, particularly those regarding pulmonary arterial resistance, are essential in assessing severity and response to vasodilating agents, preventing postoperative crisis, and evaluating the possibility of intracardiac repair. Advanced therapy with pulmonary vasodilating agents appears effective. Operative risk is similar for individuals with and without DS, except among patients with a complete atrioventricular canal defect.

Imaging findings in Down syndrome

Down syndrome, or trisomy 21, is the most common chromosomal anomaly and is characterized by intellectual disability and a typical facies. People with Down syndrome can have abnormalities of multiple organ systems. Cardiac and respiratory system involvement is the most common cause of morbidity and mortality, although every organ system can be affected. Patients may present prenatally with findings on screening sonography. If the diagnosis is not made prenatally, it is apparent at birth because of the characteristic facial features and musculoskeletal findings. Children with Down syndrome present to the radiology department at various ages depending on the severity of the specific finding. The purpose of this paper is to review the most common antenatal and postnatal imaging findings of Down syndrome as they manifest throughout the body.

Use of palivizumab in infants and young children with severe respiratory disease: a Delphi study

OBJECTIVE

To achieve a consensus of opinion among an expert group of pediatric pulmonologists regarding the appropriateness of the off-label use of palivizumab for some pediatric patients with severe respiratory diseases.

METHODS

A two-round modified Delphi technique was used. A 43-item self-administered questionnaire grouped into seven clinical scenarios was developed. Level of agreement for each statement was ranked on a 0-9 scale with 0 being total disagreement and 9 total agreement. Consensus was sought through the feedback of information and iteration. The final responses were evaluated for median and interquartile range to determine which questions the group had reached consensus about, either affirmatively or negatively.

RESULTS

Consensus was obtained for 24/43 statements (55.81%), including use of palivizumab for prevention of respiratory syncytial virus (RSV) infection in children with severe respiratory involvement due to neuromuscular disease, congenital or acquired immunodeficiency, storage disease, cystic fibrosis, diseases involving impaired ciliary clearance, patients operated on esophageal atresia and/or tracheoesophageal fistula, diaphragmatic hernia, bronchopulmonary malformations, severe tracheomalacia, lung transplant recipients and patients in the waiting list for lung transplant, patients oxygen-dependent for severe interstitial pulmonary disease and patients with severe pulmonary hypertension. Consensus against the use of palivizumab as prevention of RSV infection was also achieved in almost all the recurrent wheezing/asthma attacks situations.

CONCLUSION

A set of indication for off-label uses of palivizumab in pediatric pulmonology was developed in accordance with the degree of professional consensus on which they were based. The applicability of the present results to clinical practice should be evaluated individually and reviewed periodically in the light of new emerging evidence. Further studies are needed to add evidence to the most frequent and clinically oriented scenarios that have shown higher levels of uncertainty.

Epidemiological and clinical data of hospitalizations associated with respiratory syncytial virus infection in children under 5 years of age in Spain: FIVE multicenter study

BACKGROUND

Respiratory syncytial virus (RSV) is an important pathogen in lower respiratory tract infections (LRTI) in infants, but there are limited data concerning patients with underlying conditions and children older than 2 years of age.

METHODS

We have designed a prospective observational multicenter national study performed in 26 Spanish hospitals (December 2011-March 2012). Investigational cases were defined as children with underlying chronic diseases and were compared with a group of previously healthy children (proportion 1:2). Clinical data were compared between the groups.

RESULTS

A total of 1763 children hospitalized due to RSV infection during the inclusion period were analyzed. Of them, 225 cases and 460 healthy children were enrolled in the study. Underlying diseases observed were respiratory (64%), cardiovascular (25%), and neurologic (12%), as well as chromosomal abnormalities (7·5%), immunodeficiencies (6·7%), and inborn errors of metabolism (3·5%). Cases were statistically older than previously healthy children (average age: 16·3 versus 5·5 months). Cases experienced hypoxemia more frequently (P < 0·001), but patients with respiratory diseases required oxygen therapy more often (OR: 2·99; 95% CI: 1·03-8·65). Mechanical ventilation was used more in patients with cardiac diseases (OR: 3·0; 95% CI: 1·07-8·44) and in those with inborn errors of metabolism (OR: 12·27; 95% CI: 2·11-71·47). This subgroup showed a higher risk of admission to the PICU (OR: 6·7, 95% CI: 1·18-38·04). Diagnosis of pneumonia was more frequently found in cases (18·2% versus 9·3%; P < 0·01).

CONCLUSIONS

A significant percentage of children with RSV infection have underlying diseases and the illness severity is higher than in healthy children.

Novel inflammatory markers, clinical risk factors and virus type associated with severe respiratory syncytial virus infection

BACKGROUND

Virus-induced inflammation contributes to respiratory syncytial virus (RSV) pathogenesis. We sought to determine the specific mediators that are associated with more severe illness in young children.

METHODS

Children ≤ 5 years of age seen in our emergency department for respiratory symptoms from September 1998 to May 2008 were eligible for enrollment. Nasopharyngeal wash samples were collected from all eligible patients, and clinical data were recorded. Individuals were included in this study if nasopharyngeal wash samples were positive for RSV only. Patients enrolled in the study were stratified by disease severity, defined as mild (not hospitalized), moderate (hospitalized) or severe (requiring intensive care unit stay). Concentrations of individual inflammatory biomarkers in nasopharyngeal wash fluids were determined using the Luminex human 30-plex assay.

RESULTS

Eight hundred fifty-one patients met study criteria: 268 (31.5%) with mild, 503 (59.1%) with moderate and 80 (9.4%) with severe illness. As expected, illness severity was directly associated with young age, prematurity, heart or lung disease, infection with RSV group A and elevated concentrations of interleukin (IL)-2R, IL-6, CXCL8, tumor necrosis factor-α, interferon-α, CCL3, CCL4 and CCL2. In addition, we report several novel and mechanistically important inflammatory biomarkers of severe RSV disease, including IL-1β, IL1-RA, IL-7, epidermal growth factor and hepatocyte growth factor.

CONCLUSIONS

In a large, longitudinal study (10 years, 851 enrolled patients) limited to RSV infection only, in which well-known risk factors are confirmed, we identified 5 novel biomarkers specifically of severe disease. These markers may ultimately serve to elucidate disease mechanisms.

Respiratory syncytial virus bronchiolitis in children

Respiratory syncytial virus is a highly infectious virus that commonly causes bronchiolitis and leads to high morbidity and a low, but important, incidence of mortality. Supportive therapy is the foundation of management. Hydration/nutrition and respiratory support are important evidence-based interventions. For children with severe disease, continuous positive airway pressure or mechanical ventilation may be necessary. Ribavirin may be used for treatment of patients with severe disease. Palivizumab provides important ongoing immunoprophylaxis during epidemic months for high-risk infants. Caregiver education and incorporating an explanation of all therapies and anticipatory guidance, including strategies for reducing the risk of infection, are vital.

Hospital admissions in children with down syndrome: experience of a population-based cohort followed from birth

Objective

Children with Down syndrome, the most common genetic cause of intellectual disability, are prone to multiple and varied health-related problems. This study describes patterns of hospitalisations for children and young people with Down syndrome in Western Australia.

Methods

Birth records were linked to the Western Australian population-based Intellectual Disability database to identify all children born with Down syndrome in Western Australia between 1 January, 1983 and 31 December, 1999. These records were linked to the Hospital Morbidity Data System to provide information on all hospitalisations up to 31 December, 2004. Hospitalisation data, coded using ICD-9CM or ICD-10 (v0.5) were grouped into clinically relevant categories using the primary diagnosis. Rates of hospital admission for all and specific diagnoses were expressed in 1000-person-years at-risk and median age at first admission and length of stay were calculated.

Results

Of the 405 children, 395 had one or more hospital admissions, totalling 3786 admissions for all children and an estimated 39.5 person-years in hospital. On average, children were admitted 9.7 times, with an estimated rate of 757.2 admissions per 1000pyr (95% CI: 680, 843). A quarter of all admissions occurred in the first year of life. The average hospital length of stay was 3.8 days (95% CI: 3.7, 4.1). Upper respiratory tract conditions affected the most children (58.5%) and accounted for 12.1% of all admissions. Other disorders which affected a high percentage of children were ear/hearing conditions (50.6%), disorders of the oral cavity (38.0%) and lower respiratory tract conditions (37.5%). Overall, children with Down syndrome were hospitalised at a rate five times (95% CI = 4.3–6.2) that of the general population.

Conclusion

Children with Down syndrome are at increased risk of morbidity for varied causes underlining the importance of comprehensive and targeted primary care for this group.

Increased risk of RSV infection in children with Down's syndrome: clinical implementation of prophylaxis in the European Union

Prospective cohort studies show that Down's syndrome (DS) is an independent risk factor for hospitalization for RSV bronchiolitis. It is unknown whether this observation has been translated into specific management for DS children. The primary goal was to assess the knowledge of healthcare providers in the European Union about RSV infection in DS children and to determine whether it influenced the implementation of prophylaxis. DS caregivers were surveyed using a standardized questionnaire, and country-specific guidelines were obtained. Fifty-three caregivers participated. Thirty-nine (86.7%) had knowledge of the increased risk of severe RSV infection in DS children, and 30 (71.4%) graded that it was important to have a statement on the use of RSV prophylaxis in existing guidelines. Twenty-eight participants had a local DS guideline; hard copies of twelve unique guidelines were obtained. Only one (8.3%) contained a statement on RSV prophylaxis for DS, and five considered such a statement for the next version. Conclusion. Most pediatricians had knowledge that DS children have an increased risk of severe RSV infection. Despite the lack of a specific RSV prophylaxis trial in DS, they felt that a statement on RSV prophylaxis in DS guidelines was important, but this was rarely present in current guidelines.

Respiratory-related hospitalizations following prophylaxis in the Canadian registry for palivizumab (2005-2012) compared to other international registries

Respiratory syncytial virus (RSV) infection occurs commonly in infants aged ≤2 years, and severe infection results in hospitalization with accompanying morbidity and mortality. Palivizumab has been available for prophylaxis for the past 15 years. Prospective data on patients who received palivizumab from 2005 to 2012 has been assembled in the Canadian registry (CARESS) to document utilization, compliance, and health outcomes in both hospital and community settings. Long-term data is necessary to evaluate the impact of palivizumab on the incidence of RSV infections, minimize healthcare resources, and identify which infant subpopulations are receiving prophylaxis. A database search was also conducted for similar information from published registries, and hospitalization rates were compared to results from randomized clinical trials (RCTs).Overall hospitalization rates (percent; range) for respiratory-related illnesses and RSV-specific infection in infants who meet standard indications for prophylaxis were 6.6 (3.3-7.7) and 1.55 (0.3-2.06), respectively, in CARESS, which closely aligns with registry data from 4 other countries, despite the former comprising the largest cohort of complex patients internationally. Overall RSV-related hospitalization rates were lower across registries compared to equivalent patients in RCTs. Registry data provides valuable information regarding real-world experience with palivizumab, while facilitating the genesis of new research themes.

The use of humanized monoclonal antibodies for the prevention of respiratory syncytial virus infection

Monoclonal antibodies are widely used both in infants and in adults for several indications. Humanized monoclonal antibodies (palivizumab) have been used for many years for the prevention of respiratory syncytial virus infection in pediatric populations (preterm infants, infants with chronic lung disease or congenital heart disease) at high risk of severe and potentially lethal course of the infection. This drug was reported to be safe, well tolerated and effective to decrease the hospitalization rate and mortality in these groups of infants by several clinical trials. In the present paper we report the development and the current use of monoclonal antibodies for prophylaxis against respiratory syncytial virus.

Allergy and acute leukaemia in children with Down syndrome: a population study. Report from the Mexican inter-institutional group for the identification of the causes of childhood leukaemia

BACKGROUND

Allergies have been described as protective factors against the development of childhood acute leukaemia (AL). Our objective was to investigate the associations between allergy history and the development of AL and acute lymphoblastic leukaemia (ALL) in children with Down syndrome (DS).

METHODS

A case-control study was performed in Mexico City. The cases (n=97) were diagnosed at nine public hospitals, and the controls (n=222) were recruited at institutions for children with DS. Odds ratios (OR) were calculated.

RESULTS

Asthma was positively associated with AL development (OR=4.18; 95% confidence interval (CI): 1.47-11.87), whereas skin allergies were negatively associated (OR=0.42; 95% CI: 0.20-0.91).

CONCLUSION

Our findings suggest that allergies and AL in children with DS share biological and immune mechanisms. To our knowledge, this is the first study reporting associations between allergies and AL in children with DS.