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

Factors associated with severe respiratory syncytial virus infection among hospitalized children in Thammasat University Hospital

Background

Respiratory syncytial virus (RSV) is one of the most significant respiratory pathogens that causes acute lower respiratory tract infections (LRTI) early in life. Most children have a history of RSV infection within 24 months of age, and recurrent infections are common throughout life.

Methods

Children under five years of age were identified through a review of medical records with a diagnosis of RSV-LRTI between 2016 and 2020. Severe RSV-LRTI was defined as a prolonged length of stay (> 7 days), admission to the intensive care unit, need for mechanical ventilation, non-invasive positive pressure ventilation, or in-hospital mortality. Factors associated with severe RSV-LRTI were investigated using univariate and multivariate analyses.

Results

During the study period, 620 patients were diagnosed with RSV-LRTI and 249 (40.16%) patients had severe RSV-LRTI. In the multivariable logistic regression analysis, the factors for severe RSV-LRTI were being under 3 months (aOR 2.18 CI 1.39-3.43, p0.001), cardiovascular disease (aOR 3.55 CI 1.56-8.06, p0.002), gastrointestinal disease (aOR 5.91 CI 1.90-18.46, p0.002), genetic disease (aOR 7.33 CI 1.43-37.54, p0.017), and pulmonary disease (aOR 9.50, CI 4.56-19.80, p<0.001). Additionally, the presence of ≥ 2 co-morbidities (aOR 6.23 CI 2.81-14.81, p<0.016), experiencing illness for more than 5 days (aOR 3.33 CI 2.19-5.06, p<0.001), co-detection of influenza (aOR 8.62 CI 1.49-38.21, p0.015), and nosocomial RSV infection (aOR 9.13 CI 1.98-41.30, p0.012), markedly increased the risk of severe RSV-LTRI. The severe RSV-LRTI group demonstrated higher hospitalization expenses (median, US $720.77 vs $278.00, respectively; p<0.001), and three infants died in-hospital.

Conclusion

Children at high risk for RSV-LRTI due to underlying genetic and gastrointestinal diseases are at an increased risk for severe RSV-LRTI. Further studies to determine the cost-effectiveness of RSV immunization in these potential co-morbidities should be initiated to prioritize RSV immunization, especially in resource-constrained regions with limited availability of nirsevimab.

Zinc metabolism and its role in immunity status in subjects with trisomy 21: chromosomal dosage effect

Introduction

Trisomy 21 (T21), which causes Down syndrome (DS), is the most common chromosomal aneuploidy in humankind and includes different clinical comorbidities, among which the alteration of the immune system has a heavy impact on patient's lives. A molecule with an important role in immune response is zinc and it is known that its concentration is significantly lower in children with T21. Different hypotheses were made about this metabolic alteration and one of the reasons might be the overexpression of superoxide dismutase 1 (SOD1) gene, as zinc is part of the SOD1 active enzymatic center.

Methods

The aim of our work is to explore if there is a linear correlation between zinc level and immune cell levels measured in a total of 217 blood samples from subjects with T21. Furthermore, transcriptome map analyses were performed using Transcriptome Mapper (TRAM) software to investigate whether a difference in gene expression is detectable between subjects with T21 and euploid control group in tissues and cells involved in the immune response such as lymphoblastoid cells, thymus and white blood cells.

Results

Our results have confirmed the literature data stating that the blood zinc level in subjects with T21 is lower compared to the general population; in addition, we report that the T21/control zinc concentration ratio is 2:3, consistent with a chromosomal dosage effect due to the presence of three copies of chromosome 21. The transcriptome map analyses showed an alteration of some gene's expression which might explain low levels of zinc in the blood.

Discussion

Our data suggest that zinc level is not associated with the levels of immunity cells or proteins analyzed themselves and rather the main role of this ion might be played in altering immune cell function.

The disease burden of respiratory syncytial virus in Infants

PURPOSE OF REVIEW

To describe the current global burden of respiratory syncytial virus (RSV) in infants and its implications for morbidity, health resources and economic costs.

RECENT FINDINGS

New prophylactic therapies are on the horizon for RSV in the form of long-acting monoclonal antibodies suitable for healthy infants and maternal immunizations.

SUMMARY

Despite being responsible for significant global infant morbidity and mortality, until recently there have been no effective therapeutics available for healthy infants to protect them from RSV. Several new drugs are likely to be available within the next few years which could help relieve a huge burden on healthcare systems over the coming winters.

Children born preterm admitted to paediatric intensive care for bronchiolitis: a systematic review and meta-analysis

BACKGROUND

To undertake a systematic review of studies describing the proportion of children admitted to a paediatric intensive care unit (PICU) for respiratory syncytial virus (RSV) and/or bronchiolitis who were born preterm, and compare their outcomes in PICU with children born at term.

METHODS

We searched Medline, Embase and Scopus. Citations and references of included articles were searched. We included studies published from the year 2000 onwards, from high-income countries, that examined children 0-18 years of age, admitted to PICU from the year 2000 onwards for RSV and/or bronchiolitis. The primary outcome was the percentage of PICU admissions born preterm, and secondary outcomes were observed relative risks of invasive mechanical ventilation and mortality within PICU. We used the Joanna Briggs Institute Checklist for Analytical Cross-Sectional Studies to assess risk of bias.

RESULTS

We included 31 studies, from 16 countries, including a total of 18,331 children. Following meta-analysis, the pooled estimate for percentage of PICU admissions for RSV/bronchiolitis who were born preterm was 31% (95% confidence interval: 27% to 35%). Children born preterm had a greater risk of requiring invasive ventilation compared to children born at term (relative risk 1.57, 95% confidence interval 1.25 to 1.97, I2 = 38%). However, we did not observe a significant increase in the relative risk for mortality within PICU for preterm-born children (relative risk 1.10, 95% confidence interval: 0.70 to 1.72, I2 = 0%), although the mortality rate was low across both groups. The majority of studies (n = 26, 84%) were at high risk of bias.

CONCLUSIONS

Among PICU admissions for bronchiolitis, preterm-born children are over-represented compared with the preterm birth rate (preterm birth rate 4.4% to 14.4% across countries included in review). Preterm-born children are at higher risk of mechanical ventilation compared to those born at term.

A Multimodal Imaging-Supported Down Syndrome Mouse Model of RSV Infection

Individuals with Down syndrome (DS) are more prone to develop severe respiratory tract infections. Although a RSV infection has a high clinical impact and severe outcome in individuals with DS, no vaccine nor effective therapeutics are available. Any research into infection pathophysiology or prophylactic and therapeutic antiviral strategies in the specific context of DS would greatly benefit this patient population, but currently such relevant animal models are lacking. This study aimed to develop and characterize the first mouse model of RSV infection in a DS-specific context. Ts65Dn mice and wild type littermates were inoculated with a bioluminescence imaging-enabled recombinant human RSV to longitudinally track viral replication in host cells throughout infection progression. This resulted in an active infection in the upper airways and lungs with similar viral load in Ts65Dn mice and euploid mice. Flow cytometric analysis of leukocytes in lungs and spleen demonstrated immune alterations with lower CD8+ T cells and B-cells in Ts65Dn mice. Overall, our study presents a novel DS-specific mouse model of hRSV infection and shows that potential in using the Ts65Dn preclinical model to study immune-specific responses of RSV in the context of DS and supports the need for models representing the pathological development.

Epidemiology and Risk Factor Analysis of Children with Bronchiolitis Admitted to the Intensive Care Unit at a Tertiary Care Center in Saudi Arabia

Bronchiolitis is a leading cause of hospitalization worldwide for children aged ≤2 years. Few studies have compared general ward and pediatric intensive care unit (PICU) admissions, particularly in Saudi Arabia. This retrospective cohort study aimed to compare the demographic and clinical characteristics of children with bronchiolitis admitted to the general ward with those admitted to the PICU. Children (≤6 years) previously diagnosed with bronchiolitis and admitted to the PICU or general ward at a tertiary center in Saudi Arabia between May 2016 and May 2021 were included. Multiplex polymerase chain reaction was used to identify respiratory viruses. Of the 417 patients enrolled, 67 (16.06%) were admitted to the PICU. The PICU group was younger (median, 2 months; interquartile range [IQR], 1-5 months) vs. (6 months; IQR, 2.65-13.25 months). There was a dramatic reduction in bronchiolitis admissions during the COVID-19 pandemic. The most common causative virus was respiratory syncytial virus (RSV) (54.9%). In the multivariate regression analysis, hypoxia, hyperinflation on X-ray, and non-RSV bronchiolitis were independently associated with PICU admission. However, a higher chronological age and cough were protective. Children with Down syndrome, immunodeficiency, or neuromuscular disorders, and intermediate preterm infants (29-33 weeks of gestation) are at a high risk of PICU admission (adjusted odds ratio: 2.4, 7.1, 2.9, and 2.9; p = 0.037, 0.046, 0.033, and 0.029, respectively). Bronchiolitis is still one of the leading causes of PICU admission. Particular attention should be paid to preventive measures, especially in the post-COVID-19 era, targeting high-risk groups.

Nosocomial RSV-related In-hospital Mortality in Children <5 Years: A Global Case Series

BACKGROUND

According to the World Health Organization, the global burden of nosocomial infections is poorly characterized as surveillance systems are lacking. Nosocomial infections occur at higher rates in low- and lower-middle-income countries (LMICs) than in high-income countries (HICs). Current global RSV burden estimates are largely based on community-acquired infection. We aimed to characterize children with nosocomial RSV-related mortality and to understand the potential impact of RSV immunization strategies.

MATERIALS

RSV GOLD is a global registry of children younger than 5 years who died with laboratory-confirmed RSV infection. We compared clinical and demographic characteristics of children with nosocomial and community-acquired RSV in-hospital mortality.

RESULTS

We included 231 nosocomial and 931 community-acquired RSV-related in-hospital from deaths from 65 countries. Age at death was similar for both groups (5.4 vs. 6 months). A higher proportion of nosocomial deaths had comorbidities (87% vs. 57%; P < 0.001) or was born preterm (46% vs. 24%; P < 0.001) than community-acquired deaths. The proportion of nosocomial deaths among all RSV deaths was lower in LMICs than in upper-middle-income countries (UMICs) and HICs (12% vs. 18% and 26%, respectively).

CONCLUSIONS

This is the first global case series of children dying with nosocomial RSV infection. Future infant-targeted immunization strategies could prevent the majority of nosocomial RSV-related deaths. Although nosocomial RSV deaths are expected to occur at highest rates in LMICs, the number of reported nosocomial RSV deaths was low in these countries. Hospital-based surveillance is needed to capture the full burden of nosocomial RSV mortality in LMICs.

Respiratory Syncytial Virus-attributable Deaths in a Major Pediatric Hospital in New South Wales, Australia, 1998-2018

BACKGROUND

Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory tract infection and an important contributor to child mortality. In this study, we estimated the frequency and described the clinical features of RSV-attributable deaths in Australian children.

METHODS

We conducted a retrospective observational study of RSV-associated deaths in hospitalized children <16 years of age over a 21-year period (1998-2018) in a pediatric tertiary/quaternary referral hospital in New South Wales (NSW), Australia. RSV-associated deaths were identified, reviewed, and classified according to RSV contribution to death. For 'RSV-attributable' deaths, we estimated frequency, case fatality ratio (CFR), and population death rate. We described demographic and clinical features of cases.

RESULTS

There were 20 RSV-attributable deaths. RSV was considered the primary cause of death for five cases and a contributory cause for 15 cases. The CFR among hospitalized cases was 0.2% (20/9779). The annual death rate was 0.6 per 10,000 hospitalized children. The population death rate was 1.2 (95% confidence interval 0.5-2.7) per million children <16 years of age in NSW. The median age at death was 28.7 months (interquartile range 8.8-75.0). All children had at least one medical comorbidity. Over half the deaths occurred in children ≥2 years of age (11, 55%). RSV healthcare-associated infection (RSV-HAI) was common (11, 55%).

CONCLUSIONS

RSV-attributable death is infrequent in this setting. Deaths occurred exclusively in children with medical comorbidity and a high proportion were RSV-HAI. Children with medical comorbidity, including those ≥2 years of age, should be prioritized for targeted prevention of RSV disease.

Examining the interseasonal resurgence of respiratory syncytial virus in Western Australia

BACKGROUND

Following a relative absence in winter 2020, a large resurgence of respiratory syncytial virus (RSV) detections occurred during the 2020/2021 summer in Western Australia. This seasonal shift was linked to SARS-CoV-2 public health measures. We examine the epidemiology and RSV testing of respiratory-coded admissions, and compare clinical phenotype of RSV-positive admissions between 2019 and 2020.

METHOD

At a single tertiary paediatric centre, International Classification of Diseases, 10th edition Australian Modification-coded respiratory admissions longer than 12 hours were combined with laboratory data from 1 January 2019 to 31 December 2020. Data were grouped into bronchiolitis, other acute lower respiratory infection (OALRI) and wheeze, to assess RSV testing practices. For RSV-positive admissions, demographics and clinical features were compared between 2019 and 2020.

RESULTS

RSV-positive admissions peaked in early summer 2020, following an absent winter season. Testing was higher in 2020: bronchiolitis, 94.8% vs 89.2% (p=0.01); OALRI, 88.6% vs 82.6% (p=0.02); and wheeze, 62.8% vs 25.5% (p<0.001). The 2020 peak month, December, contributed almost 75% of RSV-positive admissions, 2.5 times the 2019 peak. The median age in 2020 was twice that observed in 2019 (16.4 vs 8.1 months, p<0.001). The proportion of RSV-positive OALRI admissions was greater in 2020 (32.6% vs 24.9%, p=0.01). There were no clinically meaningful differences in length of stay or disease severity.

INTERPRETATION

The 2020 RSV season was in summer, with a larger than expected peak. There was an increase in RSV-positive non-bronchiolitis admissions, consistent with infection in older RSV-naïve children. This resurgence raises concern for regions experiencing longer and more stringent SARS-CoV-2 public health measures.

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.

Palivizumab for preventing severe respiratory syncytial virus (RSV) infection in children

BACKGROUND

Respiratory viruses are the leading cause of lower respiratory tract infection (LRTI) and hospitalisation in infants and young children. Respiratory syncytial virus (RSV) is the main infectious agent in this population. Palivizumab is administered intramuscularly every month during five months in the first RSV season to prevent serious RSV LRTI in children. Given its high cost, it is essential to know if palivizumab continues to be effective in preventing severe RSV disease in children.

OBJECTIVES

To assess the effects of palivizumab for preventing severe RSV infection in children.

SEARCH METHODS

We searched CENTRAL, MEDLINE, three other databases and two trials registers to 14 October 2021, together with reference checking, citation searching and contact with study authors to identify additional studies. We searched Embase to October 2020, as we did not have access to this database for 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), including cluster-RCTs, comparing palivizumab given at a dose of 15 mg/kg once a month (maximum five doses) with placebo, no intervention or standard care in children 0 to 24 months of age from both genders, regardless of RSV infection history.  DATA COLLECTION AND ANALYSIS: We used Cochrane's Screen4Me workflow to help assess the search results. Two review authors screened studies for selection, assessed risk of bias and extracted data. We used standard Cochrane methods. We used GRADE to assess the certainty of the evidence. The primary outcomes were hospitalisation due to RSV infection, all-cause mortality and adverse events. Secondary outcomes were hospitalisation due to respiratory-related illness, length of hospital stay, RSV infection, number of wheezing days, days of supplemental oxygen, intensive care unit length of stay and mechanical ventilation days.

MAIN RESULTS

We included five studies with  a total of 3343 participants. All studies were parallel RCTs, assessing the effects of 15 mg/kg of palivizumab every month up to five months compared to placebo or no intervention in an outpatient setting, although one study also included hospitalised infants. Most of the included studies were conducted in children with a high risk of RSV infection due to comorbidities like bronchopulmonary dysplasia and congenital heart disease. The risk of bias of outcomes across all studies was similar and predominately low.  Palivizumab reduces hospitalisation due to RSV infection at two years' follow-up (risk ratio (RR) 0.44, 95% confidence interval (CI) 0.30 to 0.64; 5 studies, 3343 participants; high certainty evidence). Based on 98 hospitalisations per 1000 participants in the placebo group, this corresponds to 43 (29 to 62) per 1000 participants in the palivizumab group. Palivizumab probably results in little to no difference in mortality at two years' follow-up (RR 0.69, 95% CI 0.42 to 1.15; 5 studies, 3343 participants; moderate certainty evidence). Based on 23 deaths per 1000 participants in the placebo group, this corresponds to 16 (10 to 27) per 1000 participants in the palivizumab group. Palivizumab probably results in little to no difference in adverse events at 150 days' follow-up (RR 1.09, 95% CI 0.85 to 1.39; 3 studies, 2831 participants; moderate certainty evidence). Based on 84 cases per 1000 participants in the placebo group, this corresponds to 91 (71 to 117) per 1000 participants in the palivizumab group. Palivizumab probably results in a slight reduction in hospitalisation due to respiratory-related illness at two years' follow-up (RR 0.78, 95% CI 0.62 to 0.97; 5 studies, 3343 participants; moderate certainty evidence). Palivizumab may result in a large reduction in RSV infection at two years' follow-up (RR 0.33, 95% CI 0.20 to 0.55; 3 studies, 554 participants; low certainty evidence). Based on 195 cases of RSV infection per 1000 participants in the placebo group, this corresponds to 64 (39 to 107) per 1000 participants in the palivizumab group. Palivizumab also reduces the number of wheezing days at one year's follow-up (RR 0.39, 95% CI 0.35 to 0.44; 1 study, 429 participants; high certainty evidence).

AUTHORS' CONCLUSIONS

The available evidence suggests that prophylaxis with palivizumab reduces hospitalisation due to RSV infection and results in little to no difference in mortality or adverse events. Moreover, palivizumab results in a slight reduction in hospitalisation due to respiratory-related illness and may result in a large reduction in RSV infections. Palivizumab also reduces the number of wheezing days. These results may be applicable to children with a high risk of RSV infection due to comorbidities. Further research is needed to establish the effect of palivizumab on children with other comorbidities known as risk factors for severe RSV disease (e.g. immune deficiencies) and other social determinants of the disease, including children living in low- and middle-income countries, tropical regions, children lacking breastfeeding, living in poverty, or members of families in overcrowded situations.

A Survey of Parental Knowledge of Respiratory Syncytial Virus and Other Respiratory Infections in Preterm Infants

PURPOSE

Evaluate parental knowledge of respiratory syncytial virus (RSV) and other respiratory infections in preterm infants.

DESIGN

Survey.

SAMPLE

Five hundred and eighty-three parents of preterm infants with generalized, Canadian provincial representation.

MAIN OUTCOME

Knowledge of RSV infection, sources of information, and parental understanding of disease risk.

RESULTS

97.9 percent (571/583) of the parents had heard about RSV, since they all had a preterm infant. Sixty-one percent reported having good knowledge of RSV; 19.4 percent had very good knowledge; 19.7 percent had little or no awareness of RSV-related infection. Most (86.3 percent) believed that RSV illness was a very serious condition; 13 percent recognized that it could be a major problem for their child. Principal sources of information were the nurse, doctor and pamphlets. Over 480 participants cited 3 or more sources of additional information-Internet, social media platforms, and educational sessions. Respiratory syncytial virus prophylaxis was a priority, but knowledge regarding the eligibility criteria for prophylaxis is essential.

Immune Dysregulation in Children With Down Syndrome

Down syndrome (DS) is the most common genetic syndrome associated with immune defects. The extent of immune dysregulation in DS is substantial, spanning the innate and adaptive systems and including anomalies in: T and B cells, monocytes, neutrophil chemotaxis, circulating cytokines, and suboptimal antibody responses which all contribute to an increased risk of infections, poorer clinical outcomes and chronic inflammation in this vulnerable cohort. Other aspects of innate immunity may also be abnormal and contribute to the increased morbidity and warrant further interrogation such as: gamma delta T cell function, the inflammasome, Toll-like receptors and their pathways. Pharmacotherapies such as pavilizumab, pneumococcal and influenza immunizations, as well as potential immunoprophylactic agents such as pidotimod, azithromycin and Broncho-Vaxom may help alleviate the infectious consequences. Children with DS need to be managed with a heightened sense of awareness and urgency in the setting of sepsis and signs of chronic inflammation need regular screening and appropriate follow up.

Respiratory syncytial virus (RSV) infection in children with medical complexity

Children with medical complexity (CMC) are vulnerable to respiratory illness hospitalization (RIH) and respiratory syncytial virus (RSV)-related hospitalization (RSVH) due to multisystem disorders and compromised airways. It is unknown whether RSV prophylaxis is effective, or if RSVH is associated with significant morbidities in CMC. The study objectives were to (1) determine the incidence of RSV-related infection in prophylaxed CMC during the first 3 years of life and (2) assess the burden of illness following RSVH. A single tertiary center, retrospective study, was conducted of CMC who received palivizumab during the 2012-2016 RSV seasons. Fifty-four subjects were enrolled; most received one (38.9%, n = 21) or two (57.4%, n = 31) seasons of prophylaxis (mean = 4.2 [SD = 1.24], palivizumab doses per season). The cohort comprised children with multiple medical conditions (n = 22, 40.8%), tracheostomy (n = 18, 33.3%), and invasive (n = 10, 18.5%) or non-invasive (n = 4, 7.4%) ventilation. Of the CMC, 24 were hospitalized 47 times for a viral-related respiratory illness. RSV incidence in the first 3 years of life was 7.4%. Viral-related RIH and RSVH rates were 44.4% (n = 24/54) and 1.9% (n = 1/54), respectively. Of the four RSV-positive children, one was ventilated for 9 days, two acquired nosocomial RSV that was managed on the ward, and one was discharged home under close complex care supervision. All four RSV-positive cases required additional oxygen during their illness. CMC experience a high viral-related RIH rate and palivizumab likely minimizes RSV-related events and associated morbidities. The efficacy of palivizumab in CMC, especially in those ≤ 3 years, should be prospectively evaluated.

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.

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.

Characteristics of children admitted to intensive care with acute bronchiolitis

To assess factors associated with outcome in children admitted to paediatric intensive care (PIC) with bronchiolitis. A retrospective study of children admitted to the PICU at St Mary's Hospital, London with bronchiolitis over a 6-year period (2011-2016). All bronchiolitis admissions < 2 years were included. Data collected particularly noted risk factors for severity, demographics, microbiology and outcome. We compared respiratory syncytial virus (RSV) with non-RSV status. Multivariate analysis was performed. Two hundred seventy-four patients were identified. Median age was 60 days (IQR 28-150 days), 63% were male, 90% were invasively ventilated and 42% were previously healthy. Pre-existing co-morbidities were present in 38%. The most frequently isolated pathogens were RSV (60%) and rhinovirus (26%). Co-infection was present in 45%, most commonly with RSV, rhinovirus and bacterial pathogens. Median length of stay (LOS) was 6 days (IQR 4.75-10). Younger age, prematurity, RSV, co-infection and co-morbidity were identified as significant risk factors for prolonged LOS. Six children died. Five of these had documented co-morbidities.

CONCLUSION

RSV causes more severe bronchiolitis than other viruses. Nearly half of children admitted to PICU with RSV were previously healthy. Current guidelines for immunoprophylaxis of RSV bronchiolitis should be re-considered. What is Known: • Bronchiolitis is one of the most common reasons for unplanned PICU admission. The most common virus causing bronchiolitis is RSV • Bronchiolitis severe enough to require admission to PICU is associated with frequent morbidity but has low mortality. What is New: • RSV causes more severe bronchiolitis than other viruses. • Nearly half of all children admitted to PICU with RSV were previously healthy.

Respiratory Syncytial Virus: Infection, Detection, and New Options for Prevention and Treatment

Respiratory syncytial virus (RSV) infection is a significant cause of hospitalization of children in North America and one of the leading causes of death of infants less than 1 year of age worldwide, second only to malaria. Despite its global impact on human health, there are relatively few therapeutic options available to prevent or treat RSV infection. Paradoxically, there is a very large volume of information that is constantly being refined on RSV replication, the mechanisms of RSV-induced pathology, and community transmission. Compounding the burden of acute RSV infections is the exacerbation of preexisting chronic airway diseases and the chronic sequelae of RSV infection. A mechanistic link is even starting to emerge between asthma and those who suffer severe RSV infection early in childhood. In this article, we discuss developments in the understanding of RSV replication, pathogenesis, diagnostics, and therapeutics. We attempt to reconcile the large body of information on RSV and why after many clinical trials there is still no efficacious RSV vaccine and few therapeutics.

Comparing First- and Second-year Palivizumab Prophylaxis in Patients With Hemodynamically Significant Congenital Heart Disease in the CARESS Database (2005-2015)

BACKGROUND

Respiratory syncytial virus hospitalization (RSVH) rates in children <2 years of age with hemodynamically significant congenital heart disease (HSCHD) are 2- to 4-fold higher compared with healthy term infants. Pediatric recommendations differ as to whether palivizumab is beneficial beyond 1 year of age. The objective of this study was to determine whether differences exist in respiratory-related illness hospitalization (RIH) and RSVH in HSCHD infants receiving palivizumab during the first year versus second year of life in the Canadian Registry of Palivizumab.

METHODS

The Canadian Registry of Palivizumab is a prospective database of infants who received ≥1 dose of palivizumab in 32 hospitals from 2005 to 2015. Demographic data were collected at enrollment and RIH events recorded monthly. Infants <24 months of age with HSCHD were recruited.

RESULTS

Of 1909 HSCHD infants, 1380 (72.3%) in the first year (mean age, 4.2 months) and 529 (27.7%) in the second year of life (mean age, 17.8 months) received prophylaxis. Baseline demographics for day-care attendance, multiple births, enrollment age and weight differed between the groups (all P < 0.05). Additionally, second year infants had a more complicated neonatal course, with significantly longer length of stay (51.2 vs. 24.9 days) compared with those in the first year. The RIH and RSVH rates in the first year were 11.2% and 2.3% and in the second year were 10.6% and 1.7%. Cox regression analysis showed similar hazard for RIH [hazard ratio, 1.9; 95% confidence interval: 0.7-4.6; P = 0.18] and RSVH [hazard ratio, 2.0; 95% confidence interval: 0.2-16.5; P = 0.52].

CONCLUSIONS

Infants in the first and second year of life had a similar RSVH hazard. These findings suggest that infants in the second year with HSCHD, who remain unstable, are equally at risk for RSVH and merit prophylaxis.

Outcome of the Respiratory Syncytial Virus related acute lower respiratory tract infection among hospitalized newborns: a prospective multicenter study

AIM

To determine the incidence and outcomes of respiratory syncytial virus (RSV)-related acute lower respiratory tract infection (ALRI) including morbidity, nosocomial infection and mortality among newborn infants who were admitted to the neonatal intensive care units (NICUs).

METHODS

A multicenter, prospective study was conducted in newborns who were hospitalized with community acquired or nosocomial RSV infection in 44 NICUs throughout Turkey. Newborns with ALRI were screened for RSV infection by Respi-Strip®-test. Main outcome measures were the incidence of RSV-associated admissions in the NICUs and morbidity, mortality and epidemics results related to these admissions.

FINDINGS

The incidence of RSV infection was 1.24% (n: 250) and RSV infection constituted 19.6% of all ALRI hospitalizations, 226 newborns (90.4%) had community-acquired whereas 24 (9.6%) patients had nosocomial RSV infection in the NICUs. Of the 250 newborns, 171 (68.4%) were full-term infants, 183 (73.2%) had a BW >2500 g. RSV-related mortality rate was 1.2%. Four NICUs reported seven outbreaks on different months, which could be eliminated by palivizumab prophylaxis in one NICU.

CONCLUSION

RSV-associated ALRI both in preterm and term infants accounts an important percent of hospitalizations in the season, and may threat other high-risk patients in the NICU.

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.