Respiratory syncytial viral infection in infants with congenital heart disease

Improving Palivizumab Administration to High-Risk Infants with Heart Disease via a Communication-Based Quality Improvement Initiative

To improve palivizumab administration in high-risk infants with congenital heart disease to 80% over 2 years at an academic children's heart center. A multidisciplinary team at our institution implemented a series of interventions over a 2-year prior. Pediatric cardiac patients were identified for palivizumab eligibility, and a baseline rate of administration was obtained. A series of communication and documentation-based interventions were implemented over the course of the next 2 years. Palivizumab eligible infants (n = 114) were determined based on guidelines after review of diagnosis code, oxygen saturation, and medications. Doses of palivizumab were tracked via the electronic health record. The primary outcome measures were the rate of monthly palivizumab doses administered per the number of eligible months and the percentage of infants who received at least 80% of eligible doses during the respiratory syncytial virus season. The rate of monthly palivizumab doses increased from 57.6% during the baseline period to 78.4% during the final year of the project (p = 0.02). The percentage of infants who received 80% of eligible doses increased from 42.1 to 60% but was not statistically significant (p = 0.20). Interventions focused on properly identifying and tracking infants eligible for palivizumab treatment significantly increased the rates of administration.

The implications of airway anomalies on children with congenital heart disease and bronchiolitis

BACKGROUND

Bronchiolitis is a common airway infection in young children. Hemodynamically significant congenital heart disease (CHD) predicts a more complicated course. However, the role of airway anomalies remains unknown.

METHODS

We retrospectively reviewed the records of patients under 2 years old, diagnosed with CHD, and admitted between January 2011 and December 2013, before the palivizumab era. Records of bronchiolitis admissions were also extracted. Patients were grouped according to CHD condition and airway anomalies.

RESULTS

A total of 230 patients with CHD were enrolled. A total of 180 (78%) and 71 (31%) patients had hemodynamically significant CHD and airway anomalies, respectively. A total of 52 (22.6%) patients were admitted for bronchiolitis 78 times. Among them, 33 (63.5%) had hemodynamically significant CHD, and 28 (53.8%) had airway anomalies. In patients with bronchiolitis admissions, the mean ventilator use, intensive care unit stay, and hospital stay were 1.08, 4.08, and 15.19 days, respectively. When compared, the mean hospital stay for bronchiolitis patients with airway anomalies was significantly longer than that of those without airway anomalies (19.8 vs. 9.9 days, p = 0.008). When further divided the patients by the presence hemodynamic significance, patients with hemodynamically significant CHD and airway anomaly had longer hospital stay than those who had neither. (21.7 vs. 8.3 days, p = 0.004) Airway anomaly was a significant risk factor for longer hospital stay in linear regression model (p = 0.007).

CONCLUSIONS

Airway anomalies are common in children with CHD and are associated with longer hospital stays on bronchiolitis admission. An active survey for airway anomalies and adequate prophylaxis for bronchiolitis infection might be important in the care of children with CHD associated with airway anomalies.

Antiviral Peptides in Antimicrobial Surface Coatings—From Current Techniques to Potential Applications

The transmission of pathogens through contact with contaminated surfaces is an important route for the spread of infections. The recent outbreak of COVID-19 highlights the necessity to attenuate surface-mediated transmission. Currently, the disinfection and sanitization of surfaces are commonly performed in this regard. However, there are some disadvantages associated with these practices, including the development of antibiotic resistance, viral mutation, etc.; hence, a better strategy is necessary. In recent years, peptides have been studied to be utilized as a potential alternative. They are part of the host immune defense and have many potential in vivo applications in drug delivery, diagnostics, immunomodulation, etc. Additionally, the ability of peptides to interact with different molecules and membrane surfaces of microorganisms has made it possible to exploit them in ex vivo applications such as antimicrobial (antibacterial and antiviral) coatings. Although antibacterial peptide coatings have been studied extensively and proven to be effective, antiviral coatings are a more recent development. Therefore, this study aims to highlight antiviral coating strategies and the current practices and application of antiviral coating materials in personal protective equipment, healthcare devices, and textiles and surfaces in public settings. Here, we have presented a review on potential techniques to incorporate peptides in current surface coating strategies that will serve as a guide for developing cost-effective, sustainable and coherent antiviral surface coatings. We further our discussion to highlight some challenges of using peptides as a surface coating material and to examine future perspectives.

Association of Respiratory Syncytial Virus Infection and Underlying Risk Factors for Death Among Young Infants Who Died at University Teaching Hospital, Lusaka Zambia

Background

Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory tract infections and child mortality. While RSV disease burden is highest in low- and middle-income countries, most knowledge about risk factors for fatal RSV disease comes from high-income settings.

Methods

Among infants aged 4 days to <6 months who died at University Teaching Hospital in Lusaka, Zambia, we tested nasopharyngeal swabs obtained postmortem for RSV using reverse transcriptase–quantitative polymerase chain reaction. Through a systematic review of death certificates and hospital records, we identified 10 broad categories of underlying medical conditions associated with infant deaths. We used backward-selection models to calculate adjusted and unadjusted risk ratios (RRs) for the association between each underlying condition and RSV status.

Results

From 720 infant deaths, 6% (44) were RSV-positive, 70% were <4 weeks old, and 54% were male. At least 1 underlying condition was found in 85% of infants, while 63% had ≥2. Prematurity/low birth weight (53% [384]) and complications of labor and delivery (32% [230]) were the most common conditions. Congenital cardiac conditions were significantly associated with an increased risk of RSV infection (4%, 32; adjusted RR: 3.57; 95% CI: 1.71–7.44). No other underlying conditions were significantly associated with RSV.

Conclusions

Other than congenital cardiac conditions, we found a lack of association between RSV and underlying risk factors. This differs from high-income settings, where RSV mortality is concentrated among high-risk infants. In this population, birth-related outcomes are the highest mortality risk factors. Improved neonatal care remains crucial in the fight against neonatal mortality.

Congenital Heart Disease: An Immunological Perspective

Congenital heart disease (CHD) poses a significant global health and economic burden-despite advances in treating CHD reducing the mortality risk, globally CHD accounts for approximately 300,000 deaths yearly. Children with CHD experience both acute and chronic cardiac complications, and though treatment options have improved, some remain extremely invasive. A challenge in addressing these morbidity and mortality risks is that little is known regarding the cause of many CHDs and current evidence suggests a multifactorial etiology. Some studies implicate an immune contribution to CHD development; however, the role of the immune system is not well-understood. Defining the role of the immune and inflammatory responses in CHD therefore holds promise in elucidating mechanisms underlying these disorders and improving upon current diagnostic and treatment options. In this review, we address the current knowledge coinciding CHDs with immune and inflammatory associations, emphasizing conditions where this understanding would provide clinical benefit, and challenges in studying these mechanisms.

Impact of early surgical correction or palliation of congenital heart defects in infants with symptomatic viral respiratory tract infections in the current era

OBJECTIVE

This study investigates the influence of timing of surgery among infants with congenital heart disease and active respiratory tract infections in a contemporary Western Canadian cohort.

METHODS

This was a retrospective matched cohort study of infants aged 1 week to 6 months undergoing surgical repair of congenital heart disease between 2014 and 2017. Case patients had active respiratory tract infections preoperatively and were matched to control patients based on primary heart lesion. The primary outcome was time to extubation.

RESULTS

We identified 20 cases (median age, 3.4 months [range, 2.4-4.3 months]) that were matched to 40 controls (1:2 ratio). In case patients, surgery occurred at a median of 1 day after the positive viral testing. There were no statistically significant differences between cases and controls in time to extubation (59 vs 34 hours [P = .12]), postoperative vasoactive scores at 24 hours (0 vs 0 [P = .53]), 48 hours (0 vs 0 [P = .23]), maximum vasoactive score in postoperative period (5 vs 5.5 [P = .54]), or time to hospital discharge (13 vs 12 days [P = .39]). Case patients had increased duration of total respiratory support (including noninvasive ventilation, 3.5 vs 2 days [P = .02]) and postoperative intensive care unit length of stay (5.5 vs 3 days [P = .01]).

CONCLUSIONS

Cardiac surgery on infants with congenital heart disease during an acute viral respiratory tract infection may yield a clinically relevant prolongation in time to extubation.

Racial/Ethnic Disparities in the Incidences of Bronchiolitis Requiring Hospitalization

BACKGROUND

Race/ethnicity is currently not considered a risk factor for bronchiolitis, except for indigenous populations in Western countries. A better understanding of the potential impact of race/ethnicity can inform programs, policies, and practices related to bronchiolitis.

METHODS

We performed a population-based, longitudinal, observational study using the State Inpatient Database from New York State in the United States. Infants born between 2009 and 2013 at term without comorbidities were followed for the first 2 years of life, up to 2015. We calculated the cumulative incidences among different race/ethnicity groups, and evaluated the risks by developing logistic regression models.

RESULTS

Of 877 465 healthy, term infants, 10 356 infants were hospitalized with bronchiolitis. The overall cumulative incidence was 11.8 per 1000 births. The cumulative incidences in non-Hispanic White, non-Hispanic Black, Hispanic, and Asian infants were 8.6, 15.4, 19.1, and 6.5 per 1000 births, respectively. In a multivariable analysis adjusting for socioeconomic status, the risks remained substantially high among non-Hispanic Black (odds ratio, 1.42; 95% confidence interval [CI], 1.34-1.51) and Hispanic infants (odds ratio, 1.77; 95% CI, 1.67-1.87), whereas being of Asian race was protective (odds ratio, .62; 95% CI, .56-.69).

CONCLUSIONS

The risks of bronchiolitis hospitalization in the first 2 years of life were substantially different by race/ethnicity, with Hispanic and Black infants having the highest rates of hospitalization. Further research is needed to develop and implement culturally appropriate public health interventions to reduce racial and ethnic health disparities in bronchiolitis.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Severe respiratory syncytial virus disease in preterm infants: a case of innate immaturity

Respiratory syncytial virus (RSV) is the most common viral pathogen associated with acute lower respiratory tract infection (LRTI) in children under 5 years of age. Severe RSV disease is associated with the development of chronic respiratory complications such as recurrent wheezing and asthma. A common risk factor for developing severe RSV disease is premature gestation and this is largely due to an immature innate immune system. This increases susceptibility to RSV since the innate immune system is less able to protect against pathogens at a time when adaptive immunity has not fully developed. This review focuses on comparing different aspects of innate immunity between preterm and term infants to better understand why preterm infants are more susceptible to severe RSV disease. Identifying early life innate immune biomarkers associated with the development of severe RSV disease, and understanding how these compare between preterm and term infants, remains a critically important question that would aid the development of interventions to reduce the burden of disease in this vulnerable population.

Rhinovirus Detection in the Nasopharynx of Children Undergoing Cardiac Surgery Is Not Associated With Longer PICU Length of Stay: Results of the Impact of Rhinovirus Infection After Cardiac Surgery in Kids (RISK) Study

OBJECTIVES

To determine whether children with asymptomatic carriage of rhinovirus in the nasopharynx before elective cardiac surgery have an increased risk of prolonged PICU length of stay.

STUDY DESIGN

Prospective, single-center, blinded observational cohort study.

SETTING

PICU in a tertiary hospital in The Netherlands.

PATIENTS

Children under 12 years old undergoing elective cardiac surgery were enrolled in the study after informed consent of the parents/guardians.

INTERVENTIONS

The parents/guardians filled out a questionnaire regarding respiratory symptoms. On the day of the operation, a nasopharyngeal swab was obtained. Clinical data were collected during PICU admission, and PICU/hospital length of stay were reported. If a patient was still intubated 3 days after operation, an additional nasopharyngeal swab was collected. Nasopharyngeal swabs were tested for rhinovirus and other respiratory viruses with polymerase chain reaction.

MEASUREMENTS AND MAIN RESULTS

Of the 163 included children, 74 (45%) tested rhinovirus positive. Rhinovirus-positive patients did not have a prolonged PICU length of stay (median 2 d each; p = 0.257). Rhinovirus-positive patients had a significantly shorter median hospital length of stay compared with rhinovirus-negative patients (8 vs 9 d, respectively; p = 0.006). Overall, 97 of the patients (60%) tested positive for one or more respiratory virus. Virus-positive patients had significantly shorter PICU and hospital length of stay, ventilatory support, and nonmechanical ventilation. Virus-negative patients had respiratory symptoms suspected for a respiratory infection more often. In 31% of the children, the parents reported mild upper respiratory complaints a day prior to the cardiac surgery, this was associated with postextubation stridor, but no other clinical outcome measures.

CONCLUSIONS

Preoperative rhinovirus polymerase chain reaction positivity is not associated with prolonged PICU length of stay. Our findings do not support the use of routine polymerase chain reaction testing for respiratory viruses in asymptomatic children admitted for elective cardiac surgery.

Emergency room endotracheal intubation in children with bronchiolitis: A cohort study using a multicenter database

BACKGROUND AND AIMS

Bronchiolitis and asthma have a clinical overlap, and it has been shown that pediatric intensive care unit (PICU) patients with asthma undergoing endotracheal intubation in a community hospital emergency room (ER) have a shorter duration of mechanical ventilation (MV) and PICU length of stay (LOS) vs children undergoing intubation in a children's hospital. We aimed to determine if the setting of intubation (community vs children's hospital ER) is associated with the duration of MV and PICU LOS among children with bronchiolitis.

METHODS

With IRB approval, data in the Virtual Pediatric Systems (VPS, LLC) database were queried for bronchiolitis patients <24 months of age admitted to one of 103 predominantly North American PICUs between 1/2009 and 1/2016 who had an endotracheal tube in place at PICU admission. There were no exclusion criteria. Extracted data included ER type (community/external or children's hospital/internal), demographics, and reported comorbidities. Outcomes analyzed were duration of MV and PICU LOS. Multivariable linear regression was used to evaluate if intubation location was independently associated with the outcomes of interest.

RESULTS

Among 1934 patients, median age was 2.0 (IQR: 1.0-4.8) months, 51% were admitted from an external ER, 41% were White, 61% were male, and 28% had ≥1 comorbidity. Median duration of MV was 6.6 (4.6-9.5) days and the median PICU LOS was 7.0 (4.6-10.6) days. Children who underwent endotracheal intubation in a children's hospital ER had a modestly longer duration of MV (6.7 [4.4-9.4] vs 6.5 [5.2-9.6] days, P < .001, Mann-Whitney U) and longer PICU LOS (7.2 [4.8-10.8] vs 6.9 [4.2-10.1] days, P = .004, Mann-Whitney U). After adjusting for confounding variables, we did not observe a significant association between the location of endotracheal intubation and duration of MV or PICU LOS.

CONCLUSION

In this cohort, and unlike outcomes of near-fatal asthma, we observed that clinical outcomes of critical bronchiolitis were similar regardless of location of endotracheal intubation.

Perception of general pediatricians in Riyadh towards vaccination of patients with congenital heart diseases

Background:

Congenital heart defected (CHD) children are often predisposed to numerous conditions ranging from arrythmias, infections, to heart failure. Proper implementation of vaccination plan and multidisciplinary acts are mandatory for maintaining such cases to reduce the mortality and morbidity. Furthermore, CHD are also at risk of vaccine adverse reaction and several blooddisseminated pathogens infections, and at risk of death if such events where to occur. Perception and Interpretation of the knowledge and experience of general pediatricians towards vaccination of patients with congenital heart diseases is a crucial element to understand, and to improve healthcare practice in Riyadh, Saudi Arabia.

Aims:

To clarify, our aim is to investigate views of different pediatricians in vaccination plans, to perceive junior and senior pediatricians, and to identify extra vaccines given to children with a congenital heart defect.

Settings and Design:

This study is a cross-sectional study that includes the distribution of 246 questionnaires through personal interview focusing on pediatric cardiologists and general pediatricians with varying years of practice and degrees. Study was conducted by six medical interns: Mohammed O. Alfakhri, Meshal F. Alhajji, Abdulrahman M. Alyani, Yahya Z. Murad, Abdulrahman E. Alghannam, Alwaleed H. Algahtani, in six different teritiary hospitals, King Abdulaziz Medical City (KAMC), King Fahad Medical City (KFMC), King Faisal Specialist Hospital (KFSH), King Salman Hospital, and Alyamamah Hospital, in Riyadh, Saudi Arabia.

Methods and Material:

Data was collected through a convenient sampling technique and was analyzed using SPSS (version 20) and rearranged to observe the most frequent information obtained from the questionnaire.

Statistical Analysis Used:

Categorical study was described in frequencies and bar charts. Chi-Square test of significance was used after the data entry to assess the significance of the values obtained.

Results and Conclusions:

There was no significant difference between the six hospitals. In the following study, 81.7% of the participants believe that patients with congenital heart diseases are combined immunodeficient, and 84.6% agreed on giving special\extra vaccine with no preference over live and\or killed vaccine. On top of that, participants believe that the extra vaccines given to congenital heart disease patients with combined immunodeficiency are meningococcal and pneumococcal vaccines, and the special vaccine given to them are respiratory syncytial virus (RSV) and influenza vaccine. To conclude, congenitally heart defected children are widespread worldwide. Children suffering from the disease are having a serious problem that affects their lives from its earliest. For that, our research mainly focuses on improving their lives by trying to reduce the effect of several other preventable diseases using vaccines as and when they need. Several other studies believed in giving extra/special vaccines that vary depending on the location of the study. However, in Riyadh, we found that most pediatricians agree on giving extra vaccines as meningococcal and pneumococcal, and RSV and influenza as special vaccines to children with congenital heart defects.

Antiviral and Antibacterial Nanostructured Surfaces with Excellent Mechanical Properties for Hospital Applications

With the rise of bacterial and viral infections including the recent outbreak of coronavirus, the requirement for novel antimicrobial strategies is also rising with urgency. To solve this problem, we have used a wet etching technique to fabricate 23 nm wide nanostructures randomly aligned as ridges on aluminum (Al) 6063 alloy surfaces. The surfaces were etched for 0.5, 1, and 3 h. The surfaces were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, contact angle goniometry, nanoindentation and atomic force microscopy. Strains of the Gram negative bacteria Pseudomonas aeruginosa and the Gram positive bacteria Staphylococcus aureus were used to evaluate the bacterial attachment behavior. For the first time, common respiratory viruses, respiratory syncytial virus (RSV) and rhinovirus (RV), were investigated for antiviral activity on nanostructured surfaces. It was found that the etched Al surfaces were hydrophilic and the nanoscale roughness enhanced with the etching time with R_rms ranging from 69.9 to 995 nm. Both bacterial cells of P. aeruginosa and S. aureus were physically deformed and were nonviable upon attachment after 3 h on the etched Al 6063 surface. This nanoscale surface topography inactivated 92 and 87% of the attached P. aeruginosa and S. aureus cells, respectively. The recovery of infectious RSV was also reduced significantly within 2 h of exposure to the nanostructured surfaces compared to the smooth Al control surfaces. There was a 3-4 log₁₀ reduction in the viability counts of rhinovirus after 24 h on the nanostructured surfaces. The nanostructured surfaces exhibited excellent durability as the surfaces sustained 1000 cycles of 2000 μN load without any damage. This is the first report that has shown the combined antibacterial and antiviral property of the nanostructured surface with excellent nanomechanical properties that could be potentially significant for use in hospital environments to stop the spread of infections arising from physical surfaces.

Time to Say Goodbye to Bronchiolitis, Viral Wheeze, Reactive Airways Disease, Wheeze Bronchitis and All That

The diagnosis and management of infants and children with a significant viral lower respiratory tract illness remains the subject of much debate and little progress. Over the decades various terms for such illnesses have been in and fallen out of fashion or have evolved to mean different things to different clinicians. Terms such as "bronchiolitis," "reactive airways disease," "viral wheeze," and many more are used to describe the same condition and the same term is frequently used to describe illnesses caused by completely different dominant pathologies. This lack of clarity is due, in large part, to a failure to understand the basic underlying inflammatory and associated processes and, in part, due to the lack of a simple test to identify a condition such as asthma. Moreover, there is a lack of insight into the fact that the same pathology can produce different clinical signs at different ages. The consequence is that terminology and fashions in treatment have tended to go around in circles. As was noted almost 60 years ago, amongst pre-school children with a viral LRTI and airways obstruction there are those with a "viral bronchitis" and those with asthma. In the former group, a neutrophil dominated inflammation response is responsible for the airways' obstruction whilst amongst asthmatics much of the obstruction is attributable to bronchoconstriction. The airways obstruction in the former group is predominantly caused by airways secretions and to some extent mucosal oedema (a "snotty lung"). These patients benefit from good supportive care including supplemental oxygen if required (though those with a pre-existing bacterial bronchitis will also benefit from antibiotics). For those with a viral exacerbation of asthma, characterized by bronchoconstriction combined with impaired b-agonist responsiveness, standard management of an exacerbation of asthma (including the use of steroids to re-establish bronchodilator responsiveness) represents optimal treatment. The difficulty is identifying which group a particular patient falls into. A proposed simplified approach to the nomenclature used to categorize virus associated LRTIs is presented based on an understanding of the underlying pathological processes and how these contribute to the physical signs.

Risk factors for hospitalized respiratory syncytial virus disease and its severe outcomes

Introduction

Respiratory syncytial virus (RSV) is a major cause of hospital admission for acute lower respiratory tract infection in young children.

Objectives

We aimed to identify risk factors for hospitalized RSV disease and its severe outcomes.

Methods

We conducted a retrospective cohort study analyzing data of a ICD‐10‐code‐based hospital surveillance for severe acute respiratory infections (SARI). Using univariable and multivariable logistic regression analysis, we assessed age‐group, gender, season, and underlying medical conditions as possible risk factors for RSV and its severe outcomes including ICU admission, application of ventilator support, and death, respectively.

Results

Of the 413 552 patients hospitalized with SARI in the database, 8761 were diagnosed with RSV from week 01/2009 to 20/2018 with 97% (8521) aged <5 years. Among children aged <5 years, age‐groups 0‐5 months (OR: 20.29, 95% CI: 18.37‐22.41) and 6 months‐1 year (OR: 4.59, 95% CI: 4.16‐5.06), and underlying respiratory and cardiovascular disorders specific to the perinatal period (OR: 1.32, 95% CI: 1.11‐1.57) were risk factors for being diagnosed with RSV. Age‐group 0‐5 months (OR: 2.39, 95% CI: 1.45‐3.94), low birth weight (OR: 6.77, 95% CI: 1.28‐35.71), preterm newborn (OR: 6.71, 95% CI: 2.19‐20.61), underlying respiratory and cardiovascular disorders specific to the perinatal period (OR: 4.97, 95% CI: 3.36‐7.34), congenital malformation of the heart (OR: 3.65, 95% CI: 1.90‐7.02), congenital malformation of the great vessels (OR: 3.50, 95% CI: 1.10‐11.18), congenital defect originating in perinatal period (OR: 4.07, 95% CI: 1.71‐9.70), cardiovascular disease (OR: 5.19, 95% CI: 2.77‐9.72), neurological disorders (OR: 6.48, 95% CI: 3.76‐11.18), blood disease (OR: 3.67, 95% CI: 1.98‐6.79), and liver disease (OR: 14.99, 95% CI: 1.49‐150.82) contributed to ICU admission in RSV cases.

Conclusions

Using ICD‐10‐based surveillance data allows to identify risk factors for hospitalized RSV disease and its severe outcomes, and quantify the risk in different age‐groups.

Host Components Contributing to Respiratory Syncytial Virus Pathogenesis

Respiratory syncytial virus (RSV) is the most prevalent viral etiological agent of acute respiratory tract infection. Although RSV affects people of all ages, the disease is more severe in infants and causes significant morbidity and hospitalization in young children and in the elderly. Host factors, including an immature immune system in infants, low lymphocyte levels in patients under 5 years old, and low levels of RSV-specific neutralizing antibodies in the blood of adults over 65 years of age, can explain the high susceptibility to RSV infection in these populations. Other host factors that correlate with severe RSV disease include high concentrations of proinflammatory cytokines such as interleukins (IL)-6, IL-8, tumor necrosis factor (TNF)-α, and thymic stromal lymphopoitein (TSLP), which are produced in the respiratory tract of RSV-infected individuals, accompanied by a strong neutrophil response. In addition, data from studies of RSV infections in humans and in animal models revealed that this virus suppresses adaptive immune responses that could eliminate it from the respiratory tract. Here, we examine host factors that contribute to RSV pathogenesis based on an exhaustive review of in vitro infection in humans and in animal models to provide insights into the design of vaccines and therapeutic tools that could prevent diseases caused by RSV.

Incidence of respiratory syncytial virus infection in children with congenital heart disease undergoing immunoprophylaxis with palivizumab in Pará state, north region of Brazil

Background

Palivizumab prophylaxis for the human respiratory syncytial virus (HRSV) has been reported to reduce the risk of hospital admissions related to HRSV in children with congenital heart disease (CHD). These children are at high risk of developing severe lower respiratory tract infection (LRTI) due to HRSV infection. Our goal was to evaluate the incidence of HRSV infection in children with CHD after being submitted to immunoprophylaxis with palivizumab in Pará state, North region of Brazil.

Methods

A prospective and observational cohort study was performed in children ≤2 years of age with CHD who received palivizumab immunoprophylaxis between January 1 and June 31, 2016. A questionnaire about basic non-medical care measures was applied to parents/legal representatives. Data on patients’ demographic characteristics, household environment, and respiratory infections were evaluated. HRSV infection was determined by qPCR.

Results

There were 104 children enrolled in this investigation and the results showed a mean age of 10.6 months, an average weight of 7.3 kg and 3.5 doses of palivizumab per children during seasonality of HRSV. Respiratory infection was observed in 27.9% of cases, of which 9.6% were LRTI. No case of children who received palivizumab immunoprophylaxis and developed influenza-like symptoms tested positive for HRSV.

Conclusion

Although the lack of a control group doesn’t allow to affirm the effectiveness of HRSV passive immunization, the immunoprophylaxis with palivizumab appeared to be totally efficient in preventing respiratory infection by HRSV in children up to two years of age with CHD.

Effect of inactivated Streptococcus pneumoniae as non-pathogenic particles on the severity of pneumonia caused by respiratory syncytial virus infection in mice

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We made inactivated Streptococcus pneumoniae (ISP) as non-pathogenic particles.

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We evaluated effects of ISP on development of pneumonia by RSV infection in mice.

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ISP didn’t show histopathological effects on lungs of RSV-infected mice.

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ISP reduced virus titer and infiltration of lymphocyte in the lungs.

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The inherent activity of ISP as particles in RSV infection is discussed.

The severity of pneumonia in respiratory syncytial virus (RSV) infection is strongly related to host immune response and external factors such as bacteria and environmental chemicals. We investigated the effect of inactivated Streptococcus pneumoniae (ISP) as non-pathogenic particles on the severity of pneumonia in RSV-infected mice. Mice were intranasally exposed to ISP before RSV infection. On day 5 post-infection, we examined tissues, virus titer, and infiltrated cells in the lungs. The ISP did not cause significant histopathological effects in the lungs of RSV infected mice, but reduced virus titer. It also reduced the ratio of lymphocyte infiltration into the lungs and consequently the ratio of macrophage increased. In addition, we found that ISP increased RANTES level in bronchoalveolar lavage fluid from RSV-infected mice on day 1 post-infection, but reduced type I interferon levels. Thus, ISP did not exacerbate pneumonia in RSV infection, rather, it might mildly reduce the severity. We characterize and discuss the inherent activity of ISP as non-pathogenic particles inducing the role of RANTES on the pneumonia in RSV infection.

A Contemporary View of Respiratory Syncytial Virus (RSV) Biology and Strain-Specific Differences

Respiratory syncytial virus (RSV) is a human respiratory pathogen which remains a leading viral cause of hospitalizations and mortality among infants in their first year of life. Here, we review the biology of RSV, the primary laboratory isolates or strains which have been used to best characterize the virus since its discovery in 1956, and discuss the implications for genetic and functional variations between the established laboratory strains and the recently identified clinical isolates.

Pulmonary hypertension during respiratory syncytial virus bronchiolitis: a risk factor for severity of illness

BACKGROUND

Respiratory syncytial virus infection is the most frequent cause of acute lower respiratory tract disease in infants. A few reports have suggested that pulmonary hypertension is associated with increased severity of respiratory syncytial virus infection. We sought to determine the association between the pulmonary hypertension detected by echocardiography during respiratory syncytial virus bronchiolitis and clinical outcomes.

METHODS

We retrospectively reviewed 154 children admitted with respiratory syncytial virus bronchiolitis who had an echocardiography performed during the admission. The association between pulmonary hypertension and clinical outcomes including mortality, intensive care unit (ICU) admission, prolonged ICU stay (&gt;10 days), tracheal intubation, and need of high frequency oscillator ventilation was evaluated.

RESULTS

Echocardiography detected pulmonary hypertension in 29 patients (18.7%). Pulmonary hypertension was observed more frequently in patients with congenital heart disease (CHD) (n = 11/33, 33%), chronic lung disease of infancy (n = 12/25, 48%), prematurity (&lt;37 weeks gestational age, n = 17/59, 29%), and Down syndrome (n = 4/10, 40%). The presence of pulmonary hypertension was associated with morbidity (p &lt; 0.001) and mortality (p = 0.02). However, in patients without these risk factors (n = 68), pulmonary hypertension was detected in five patients who presented with shock or poor perfusion. Chronic lung disease was associated with pulmonary hypertension (OR = 5.9, 95% CI 2.2-16.3, p = 0.0005). Multivariate logistic analysis demonstrated that pulmonary hypertension is associated with ICU admission (OR = 6.4, 95% CI 2.2-18.8, p = 0.0007), intubation (OR = 4.7, 95% CI 1.8-12.3, p = 0.002), high frequency oscillator ventilation (OR = 8.4, 95% CI 2.95-23.98, p &lt; 0.0001), and prolonged ICU stay (OR = 4.9, 95% CI 2.0-11.7, p = 0.0004).

CONCLUSIONS

Pulmonary hypertension detected by echocardiography during respiratory syncytial virus infection was associated with increased morbidity and mortality. Chronic lung disease was associated with pulmonary hypertension detected during respiratory syncytial virus bronchiolitis. Routine echocardiography is not warranted for previously healthy, haemodynamically stable patients with respiratory syncytial virus bronchiolitis.

A Case of Bilateral Spontaneous Chylothorax with Respiratory Syncytial Virus Bronchiolitis

A case of bilateral spontaneous chylothorax with respiratory syncytial virus (RSV) bronchiolitis has never been reported. We report the case of a 7-month-old boy born at 33 weeks gestation with a history of Down syndrome, atrial septal defect, pulmonary hypertension, and chronic lung disease, hospitalized due to RSV bronchiolitis who developed bilateral spontaneous chylothorax with exacerbation of pulmonary hypertension (PH). The patient died after 9 weeks of mechanical ventilation and treatment for PH. The autopsy showed acute infectious signs, a chronic interstitial lung disease with pulmonary hypertensive changes and subpleural cysts with no evidence of congenital lymphangiectasia. The cause of chylothorax in this child could be multifactorial. However, worsening pulmonary hypertension with RSV infection might have partially contributed to the development of chylothorax through elevated superior venous cava pressure. Thoracentesis should be considered for patients with Down syndrome and PH associated with congenital heart disease who develop persistent pleural effusion during RSV bronchiolitis to rule out chylothorax.

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.

New mouse model of pulmonary hypertension induced by respiratory syncytial virus bronchiolitis

Pulmonary hypertension (PH) has been observed in up to 75% of infants with moderate to severe respiratory syncytial virus (RSV) bronchiolitis and is associated with significant morbidity and mortality in infants with congenital heart disease. The purpose of the present study was to establish a mouse model of PH secondary to RSV bronchiolitis that mimics the disease etiology as it occurs in infants. Neonatal mice were infected with RSV at 5 days of age and then reinfected 4 wk later. Serum-free medium was administered to age-matched mice as a control. Echocardiography and right ventricular systolic pressure (RVSP) measurements via right jugular vein catheterization were conducted 5 and 6 days after the second infection, respectively. Peripheral capillary oxygen saturation monitoring did not indicate hypoxia at 2-4 days post-RSV infection, before reinfection, and at 2-7 days after reinfection. RSV-infected mice had significantly higher RVSP than control mice. Pulsed-wave Doppler recording of the pulmonary blood flow by echocardiogram demonstrated a significantly shortened pulmonary artery acceleration time and decreased pulmonary artery acceleration time-to-ejection time ratio in RSV-infected mice. Morphometry showed that RSV-infected mice exhibited a significantly higher pulmonary artery medial wall thickness and had an increased number of muscularized pulmonary arteries compared with control mice. These findings, confirmed by RVSP measurements, demonstrate the development of PH in the lungs of mice infected with RSV as neonates. This animal model can be used to study the pathogenesis of PH secondary to RSV bronchiolitis and to assess the effect of treatment interventions. NEW & NOTEWORTHY This is the first mouse model of respiratory syncytial virus-induced pulmonary hypertension, to our knowledge. This model will allow us to decipher molecular mechanisms responsible for the pathogenesis of pulmonary hypertension secondary to respiratory syncytial virus bronchiolitis with the use of knockout and/or transgenic animals and to monitor therapeutic effects with echocardiography.

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.

Predictors of prolonged length of hospital stay for infants with bronchiolitis

Among inpatients suffering from bronchiolitis, approximately a quarter may undergo a prolonged length of stay (LOS) for the treatment of their respiratory condition. However, there have been few research studies that have evaluated variables that may be associated with a prolonged LOS in these patients, especially in low-income and middle-income countries, where the clinical and economic burden of the disease is the greatest. In an analytical single-center cross-sectional study, we included a population of patients with acute bronchiolitis hospitalized between March and June 2016. We collected demographic and clinical information and the LOS of each patient. Prolonged LOS for bronchiolitis was defined as at least one hospital stay of 5 or more days. A total of 303 patients were included, with 176 (58.1%) male and a median (IQR) age of 3.0 (1.0-7.0) months. After controlling for gender, history of bronchopulmonary dysplasia, number of days with respiratory symptoms, the presence of apnea as an initial manifestation of bronchiolitis, and other underlying disease conditions, we found that the independent predictors of prolonged LOS for bronchiolitis in our study population included age (OR 0.92; 95% CI 0.84 to 0.99; p=0.049), history of prematurity (OR 6.34; 95% CI 1.10 to 36.46; p=0.038), respiratory syncytial virus isolation (OR 1.92; 95% CI 1.02 to 3.73; p=0.048), and initial oxygen saturation (OR 0.94; 95% CI 0.88 to 0.98; p=0.048). The factors identified should be taken into account when planning policies to reduce the duration of hospital stay in infants with bronchiolitis.

Perinatal exposure to tetrabromobisphenol A (TBBPA), a brominated flame retardant, exacerbated the pneumonia in respiratory syncytial virus (RSV)-infected offspring mice

To investigate the effects of perinatal exposure to tetrabromobisphenol A (TBBPA), a brominated flame retardant, on the immune system, a respiratory syncytial virus (RSV) infection mouse model was utilized. Female mice were exposed to TBBPA mixed with the diet from 10 days after conception to weaning on postnatal day 21. Offspring mice were infected intranasally with A2 strain of RSV. Although no general toxicological sign was observed, the pulmonary viral titers of offspring mice exposed to 0.1% TBBPA were significantly increased compared with the control on day 5 post-infection. TBBPA did not affect RSV growth in vitro. Histopathological analysis confirmed that the exacerbation of interstitial pneumonia was due to TBBPA- exposure in the lung tissues in RSV-infected offspring. Moreover, gene expression of interleukin (IL)-24 was shown to be elevated typically in the lung tissues of TBBPA-treated offspring by a DNA microarray and was also confirmed by immunohistopathological analysis using an anti-IL-24 antibody. Thus, developmental exposure to TBBPA affected the immune response to RSV infection, resulting in the exacerbation of pneumonia. Thus, IL-24 should be a key molecule to understand the mechanism of action of TBBPA.

CHD and respiratory syncytial virus: global expert exchange recommendations

BACKGROUND

Palivizumab is the standard immunoprophylaxis against serious disease due to respiratory syncytial virus infection. Current evidence-based prophylaxis guidelines may not address certain children with CHD within specific high-risk groups or clinical/management settings.

METHODS

An international steering committee of clinicians with expertise in paediatric heart disease identified key questions concerning palivizumab administration; in collaboration with an additional international expert faculty, evidence-based recommendations were formulated using a quasi-Delphi consensus methodology.

RESULTS

Palivizumab prophylaxis was recommended for children with the following conditions: <2 years with unoperated haemodynamically significant CHD, who are cyanotic, who have pulmonary hypertension, or symptomatic airway abnormalities; <1 year with cardiomyopathies requiring treatment; in the 1st year of life with surgically operated CHD with haemodynamically significant residual problems or aged 1-2 years up to 6 months postoperatively; and on heart transplant waiting lists or in their 1st year after heart transplant. Unanimous consensus was not reached for use of immunoprophylaxis in children with asymptomatic CHD and other co-morbid factors such as arrhythmias, Down syndrome, or immunodeficiency, or during a nosocomial outbreak. Challenges to effective immunoprophylaxis included the following: multidisciplinary variations in identifying candidates with CHD and prophylaxis compliance; limited awareness of severe disease risks/burden; and limited knowledge of respiratory syncytial virus seasonal patterns in subtropical/tropical regions.

CONCLUSION

Evidence-based immunoprophylaxis recommendations were formulated for subgroups of children with CHD, but more data are needed to guide use in tropical/subtropical countries and in children with certain co-morbidities.

Respiratory syncytial virus: an overview of infection biology and vaccination strategies

Respiratory syncytial virus (RSV) is the foremost cause of lower respiratory tract infections, especially in infants and young children. To date, there is no licensed vaccine available for RSV. Only option to restrain RSV is a prophylactic treatment in the form of monoclonal antibody (palivizumab). However, it is quite expensive and used in few patients with co-morbidities. In ongoing research, virologists contemplate about various vaccine candidates to control RSV infection. This review will help in understating the RSV pathobiology and encompass the advancement on various vaccine candidates that would lead to reduce the incidence, mortality and morbidity. Furthermore, it will lighten up the different avenues which might be useful for the development of novel vaccination approaches.

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.

Severity of Respiratory Syncytial Virus Lower Respiratory Tract Infection With Viral Coinfection in HIV-Uninfected Children

Background.

Molecular diagnostics enable sensitive detection of respiratory viruses, but their clinical significance remains unclear in pediatric lower respiratory tract infection (LRTI). We aimed to determine whether viral coinfections increased life-threatening disease in a large cohort.

Methods.

Molecular testing was performed for respiratory viruses in nasopharyngeal aspirates collected from children aged <5 years within 24 hours of hospital admission during sentinel surveillance for severe acute respiratory illness (SARI) hospitalization conducted in South Africa during February 2009–December 2013. The primary outcome was life-threatening disease, defined as mechanical ventilation, intensive care unit admission, or death.

Results.

Of 2322 HIV-uninfected children with respiratory syncytial virus (RSV)–associated LRTI, 1330 (57.3%) had RSV monoinfection, 38 (1.6%) had life-threatening disease, 575 (24.8%) had rhinovirus, 347 (14.9%) had adenovirus (ADV), and 30 (1.3%) had influenza virus. RSV and any other viral coinfection was not associated with severe disease (odds ratio [OR], 1.4; 95% confidence interval [CI], OR, 0.74; 95% CI, .39–1.4), ADV coinfection had increased odds of life-threatening disease (adjusted OR, 3.4; 95% CI, 1.6–7.2; P = .001), and influenza coinfection had increased odds of life-threatening disease and prolonged length of stay (adjusted OR, 2.1; 95% CI, 1.0–4.5; P = .05) compared with RSV monoinfection.

Conclusions.

RSV coinfection with any respiratory virus is not associated with more severe disease when compared to RSV alone in this study. However, increased life-threatening disease in RSV-ADV and RSV-influenza coinfection warrants further study.

Bronchiolitis Score of Sant Joan de Déu: BROSJOD Score, validation and usefulness

OBJECTIVE

To validate the bronchiolitis score of Sant Joan de Déu (BROSJOD) and to examine the previously defined scoring cutoff.

PATIENTS AND METHODS

Prospective, observational study. BROSJOD scoring was done by two independent physicians (at admission, 24 and 48 hr). Internal consistency of the score was assessed using Cronbach's α. To determine inter-rater reliability, the concordance correlation coefficient estimated as an intraclass correlation coefficient (CCC) and limits of agreement estimated as the 90% total deviation index (TDI) were estimated. An expert opinion was used to classify patients according to clinical severity. A validity analysis was conducted comparing the 3-level classification score to that expert opinion. Volume under the surface (VUS), predictive values, and probability of correct classification (PCC) were measured to assess discriminant validity.

RESULTS

About 112 patients were recruited, 62 of them (55.4%) males. Median age: 52.5 days (IQR: 32.75-115.25). The admission Cronbach's α was 0.77 (CI95%: 0.71; 0.82) and at 24 hr it was 0.65 (CI95%: 0.48; 0.7). The inter-rater reliability analysis was: CCC at admission 0.96 (95%CI 0.94-0.97), at 24 h 0.77 (95%CI 0.65-0.86), and at 48 hr 0.94 (95%CI 0.94-0.97); TDI 90%: 1.6, 2.9, and 1.57, respectively. The discriminant validity at admission: VUS of 0.8 (95%CI 0.70-0.90), at 24 h 0.92 (95%CI 0.85-0.99), and at 48 hr 0.93 (95%CI 0.87-0.99). The predictive values and PCC values were within 38-100% depending on the level of clinical severity.

CONCLUSION

There is a high inter-rater reliability, showing the BROSJOD score to be reliable and valid, even when different observers apply it. Pediatr Pulmonol. 2017;52:533-539. © 2016 Wiley Periodicals, Inc.

Impact of Viral Respiratory Pathogens on Outcomes After Pediatric Cardiac Surgery

OBJECTIVES

Viral respiratory infection is commonly considered a relative contraindication to elective cardiac surgery. We aimed to determine the frequency and outcomes of symptomatic viral respiratory infection in pediatric cardiac surgical patients.

DESIGN

Retrospective cohort study of children undergoing cardiac surgery. Symptomatic children were tested using a multiplex Polymerase Chain Reaction (respiratory virus polymerase chain reaction) panel capturing nine respiratory viruses. Tests performed between 72 prior to and 48 hours after PICU admission were included. Mortality, length of stay in PICU, and intubation duration were investigated as outcomes.

SETTING

Tertiary PICU providing state-wide pediatric cardiac services.

PATIENTS

Children less than 18 years admitted January 1, 2008 to November 29, 2014 for cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

Respiratory virus polymerase chain reaction was positive in 73 (4.2%) of 1,737 pediatric cardiac surgical admissions, including 13 children with multiple viruses detected. Commonly detected viruses included rhino/enterovirus (48%), adenovirus (32%), parainfluenza virus 3 (10%), and respiratory syncytial virus (3%). Pediatric Index of Mortality 2, Aristotle scores, and cardiopulmonary bypass times were similar between virus positive and negative/untested cohorts. Respiratory virus polymerase chain reaction positive patients had a median 2.0 days greater PICU length of stay (p < 0.001) and longer intubation duration (p < 0.001). Multivariate analysis adjusting for age, Aristotle score, cardiopulmonary bypass duration, and need for preoperative PICU admission confirmed that virus positive patients had significantly greater intubation duration and PICU length of stay (p < 0.001). Virus positive patients were more likely to require PICU admission greater than 4 days (odds ratio, 3.5; 95% CI, 1.9-6.2) and more likely to require intubation greater than 48 hours (odds ratio, 2.5; 95% CI, 1.4-4.7). There was no difference in mortality. No association was found between coinfection and outcomes.

CONCLUSIONS

Pediatric cardiac surgical patients with a respiratory virus detected at PICU admission had prolonged postoperative recovery with increased length of stay and duration of intubation. Our results suggest that postponing cardiac surgery in children with symptomatic viral respiratory infection is appropriate, unless the benefits of early surgery outweigh the risk of prolonged ventilation and PICU stay.

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.

Respiratory syncytial virus hospitalisation trends in children with haemodynamically significant heart disease, 1997-2012

OBJECTIVE

The aim of the study was to evaluate the trends in respiratory syncytial virus-related hospitalisations and associated outcomes in children with haemodynamically significant heart disease in the United States of America. Study design The Kids' Inpatient Databases (1997-2012) were used to estimate the incidence of respiratory syncytial virus hospitalisation among children ⩽24 months with or without haemodynamically significant heart disease. Weighted multivariable logistic regression and chi-square tests were used to evaluate the trends over time and factors associated with hospitalisation, comparing eras before and after publication of the 2003 American Academy of Pediatrics palivizumab immunoprophylaxis guidelines. Secondary outcomes included in-hospital mortality, morbidity, length of stay, and cost.

RESULTS

Overall, 549,265 respiratory syncytial virus-related hospitalisations were evaluated, including 2518 (0.5%) in children with haemodynamically significant heart disease. The incidence of respiratory syncytial virus hospitalisation in children with haemodynamically significant heart disease decreased by 36% when comparing pre- and post-palivizumab guideline eras versus an 8% decline in children without haemodynamically significant heart disease (p<0.001). Children with haemodynamically significant heart disease had higher rates of respiratory syncytial virus-associated mortality (4.9 versus 0.1%, p<0.001) and morbidity (31.5 versus 3.5%, p<0.001) and longer hospital length of stay (17.9 versus 3.9 days, p<0.001) compared with children without haemodynamically significant heart disease. The mean cost of respiratory syncytial virus hospitalisation in 2009 was $58,166 (95% CI:$46,017, $70,315).

CONCLUSIONS

These data provide stakeholders with a means to evaluate the cost-utility of various immunoprophylaxis strategies.

Inhibitory Effect of Pyridobenzoazoles on Orthomyxo-and Paramyxovirus Replication in vitro

Among thirteen newly synthesized pyridobenzoazole derivatives which have been examined for anti-myxovirus and antiherpesvirus activities, three benzimidazoles emerged as potent anti-orthomyxo- or paramyxovirus compounds. 4-Cyano-2-benzamide-1-oxo-1,5-dihydropyrido[1,2a]benzimidazole (CBO-PB) showed broad antiviral activities against paramyxo-and orthomyxoviruses with EC50 of 0.1–2.0 μg ml−1, and 2-cyano-1-amino derivatives of CBO-PB (CCI-PB) were inhibitory to paramyxoviruses at 1.4–8.5 (μg ml−1 by a plaque reduction method. The third compound, 2-ethoxycarbonyl derivatives of CCI-PB was inhibitory only to respiratory syncytial virus (RSV) at 15–28 μg ml−1. Selectivity indexes of these 3 compounds for RSV in HeLa cells were 60, 86, and >13, respectively. All three compounds inhibited syncytium formation of RSV and Parainfluenzavirus (PFLUV) type 3 at comparable concentrations with EC50 for plaque formation. They inhibited antigen production of RSV and PFLUV at the concentrations that were 4 to 20-fold higher than those needed for plaque reduction, but they did not inhibit adsorption of virus to cells at all. All three compounds inhibited the growth of RSV in HeLa cells at 4-fold higher concentrations than their EC50 for plaque reduction.

Detection of Respiratory Syncytial Virus using Direct Fluorescent Antibody Assay in Paediatric Patients with Acute Respiratory Tract Infection

INTRODUCTION

Severe Respiratory Syncytial Virus (RSV) pulmonary disease manifesting as bronchiolitis and pneumonia continues to play a major role in the childhood mortality and morbidity. Hence the present study was undertaken to evaluate the prevalence of RSV among hospitalized children presenting with Acute Respiratory Tract Infection (ARTI) and its correlation with risk factors.

AIM

To determine the occurrence of RSV related respiratory tract infection in paediatric patients and to access the risk factors and clinical features associated.

MATERIALS AND METHODS

RSV antigen detection was performed by Direct Fluorescent Antibody (DFA) staining on 100 nasopharyngeal aspirate collected from hospitalized children below 5 years of age with a diagnosis of ARTI.

RESULTS

Out of the 100 samples tested for RSV with DFA, 22 (22%) were found RSV positive with a mean age of 12 months and a male to female ratio of (1.75:1). Clinical features significantly associated with RSV were wheezing and breathlessness. Congenital heart disease (CHD) and prematurity were the risk factors significantly associated with RSV infection.

CONCLUSION

RSV infection is a significant cause of morbidity among children presenting with ARTI. In resource limited countries DFA can be used as an important tool for rapid detection of RSV and can potentially eliminate prolonged hospitalization and unnecessary use of antibiotics.

Respiratory syncytial virus-associated hospitalizations over three consecutive seasons in children with congenital heart disease

The purpose of this investigation was to analyze the burden of respiratory syncytial virus (RSV)-related hospitalizations in infants and children with congenital heart disease (CHD) over three consecutive RSV seasons. Retrospectively, all children with hemodynamically significant (HS-CHD) and not significant (HNS-CHD) CHD born between 2004 and 2008 at a tertiary care university hospital and identified by ICD-10 diagnoses were included. Data on RSV-related hospitalizations over the first three years of life covering at least three RSV seasons (November-April) were analyzed. The overall incidence of RSV-related hospitalization was 9.6 % (58/602), without a statistically significant difference between HS-CHD and HNS-CHD (7.3 % vs. 10.4 %; p = 0.258). Recommendation of palivizumab prophylaxis did not influence the RSV hospitalization rates between groups. Patients with HS-CHD and early surgery were significantly less often hospitalized due to RSV compared to those with delayed surgery (1.3 % vs. 14.3 %; p = 0.003). The median duration of hospitalization was 8.5 days (HS-CHD: 14 vs.

HNS-CHD

7 days; p = 0.003). Thirteen patients (22.4 %) were admitted to the intensive care unit (ICU), for a median of 10 days. The median age at admission was 2 months, with a significant difference between HS-CHD and HNS-CHD (6 vs. 2 months; p = 0.001). The majority (97 %) of RSV-related hospitalizations occurred before 12 months of age. Patients with HS-CHD had a significantly more severe course of RSV disease and were older at the time of hospitalization. Early surgery seemed to significantly reduce the risk of RSV hospitalization during the first RSV season.

Stable long-term cultures of self-renewing B cells and their applications

Monoclonal antibodies are essential therapeutics and diagnostics in a large number of diseases. Moreover, they are essential tools in all sectors of life sciences. Although the great majority of monoclonal antibodies currently in use are of mouse origin, the use of human B cells to generate monoclonal antibodies is increasing as new techniques to tap the human B cell repertoire are rapidly emerging. Cloned lines of immortalized human B cells are ideal sources of monoclonal antibodies. In this review, we summarize our studies to the regulation of the replicative life span, differentiation, and maturation of B cells that led to the development of a platform that uses immortalization of human B cells by in vitro genetic modification for antibody development. We describe a number of human antibodies that were isolated using this platform and the application of the technique in other species. We also discuss the use of immortalized B cells as antigen-presenting cells for the discovery of tumor neoantigens.

Antiviral effect of emodin from Rheum palmatum against coxsakievirus B5 and human respiratory syncytial virus in vitro

Viral infections are the major causes of morbidity and mortality in elderly people and young children throughout the world. The most common pathogens include coxsackie virus (CV) and respiratory syncytial virus (RSV). However, no antiviral agents with low toxicity and drug resistance are currently available in clinic therapy. The present study aimed to examine the antiviral activities of emodin (an ingredient of Rheum palmatum) against CVB5 and RSV infections, in an attempt to discover new antiviral agents for virus infection. The monomer emodin was extracted and isolated from Rheum palmatum. The antiviral activities of emodin on HEp-2 cells were evaluated, including virus replication inhibition, virucidal and anti-absorption effects, by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tet-razolium bromide (MTT) assay and plaque reduction assay (PRA). The kinetics of virus inhibition by emodin in a period of 14 h was further determined by plaque assay and quantitative real time PCR (qPCR). Cytokine (IFN-γ, TNF-α) mRNA expressions after emodin treatment (7.5, 15, 30 μmol/L) were also assessed by qPCR post-infection. The results showed that emodin had potent inhibitory activities against CVB5 and RSV, with the 50% effective concentration (EC₅₀) ranging from 13.06 to 14.27 μmol/L and selectivity index (SI) being 5.38–6.41 μmol/L. However, emodin couldn’t directly inactivate the viruses or block their absorption to cells. It acted as a biological synthesis inhibitor against CVB₄ and RSV in a concentration- and time-dependent manner, especially during the first 0–4 h post-infection. Moreover, emodin could decrease the mRNA expression of IFN-α but enhance TNF-γ expression significantly compared to the viral controls in vitro. Our results provide a molecular basis for development of emodin as a novel and safe antiviral agent for human enterovirus and respiratory virus infection in the clinical therapy.

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.

Predictors of severe disease in a hospitalized population of children with acute viral lower respiratory tract infections

Although predictors of severe viral acute lower respiratory infections (ALRIs) in children have been reported, there have been few research studies performed in low- and middle-income countries (LMIC). The aim of the present study was to determine predictors of disease severity in a population of Colombian children <5 years of age with ALRI. In a prospective cohort study, we determined independent predictors of severe ALRI in a hospitalized population of children under 5 years old with ALRI during a 1-year period. We included both underlying disease conditions and the infecting respiratory viruses as predictor variables of severe disease. We defined severe disease as the necessity of pediatric intensive care unit admission. Of a total of 1,180 patients admitted with a diagnosis of ALRI, 416 (35.3%) were included because they were positive for any kind of respiratory virus. After controlling for potential confounders, it was found that a history of pulmonary hypertension (RR 3.62; CI 95% 2.38-5.52; P < 0.001) and a history of recurrent wheezing (RR 1.77; CI 95% 1.12-2.79; P = 0.015) were independent predictors of severe disease. The present study shows that respiratory viruses are significant causes of ALRI in infants and young children in Colombia, a typical tropical LMIC, especially during the rainy season. Additionally, the results of the present study show that clinical variables such as a history of pulmonary hypertension and a history of recurrent wheezing are more relevant for predicting ALRI severity than the infecting respiratory viruses.

Efficacy of palivizumab prophylaxis among infants with congenital heart disease: A case control study

BACKGROUND

Palivizumab prophylaxis for RSV has been consistently reported to reduce the risk of hospital admissions related to RSV infection in children with symptomatic cardiac disease. This study was designed to investigate the efficacy of palivizumab prophylaxis among infants with congenital heart disease (CHD) in Turkey.

METHODS

A total of 91 infants with CHD who received palivizumab prophylaxis and 96 infants with CHD without prophylaxis (0-12 months:52; 12-24 months:44) were included in this single-center retrospective case control study. Data on patient characteristics, household environment, and LRTIs were evaluated.

RESULTS

In patients without prophylaxis, the rate of overall lower respiratory tract infections (LRTIs) (P < 0.001), complicated LRTIs (P = 0.006), LRTI-related hospitalization (P < 0.001) and ICU admission (P = 0.008) were significantly higher than control patients. Weight <10th percentile (odds ratio (OR) 5.78, 95% confidence interval (CI):1.37; 24.4, P < 0.001) and concomitant chromosome abnormality (OR 4.01, 95% CI:1.01;16.45, P < 0.001) in patients with prophylaxis, while presence of a sibling <11 years of age (OR 3.38, 95% CI: 1.21; 9.46, P < 0.001) and congestive heart failure (OR 8.63, 95% CI: 2.81; 26.6, P < 0.001) in the control group were the significant correlates of LRTI-related hospitalization.

CONCLUSION

Our findings revealed significantly lower rate of overall and complicated LRTIs, LRTI-related hospitalization and ICU admissions in infants with CHD via palivizumab prophylaxis.

Viral Specific Factors Contribute to Clinical Respiratory Syncytial Virus Disease Severity Differences in Infants

Background

There is a wide range of severity of respiratory syncytial viral (RSV) disease in previously healthy infants. Host factors have been well demonstrated to contribute to disease severity differences. However the possibility of disease severity differences being produced by factors intrinsic to the virus itself has rarely been studied.

Methods

Low-passage isolates of RSV collected prospectively from infants with different degrees of RSV disease severity were evaluated in vitro, holding host factors constant, so as to assess whether isolates induced phenotypically different cytokine/chemokine concentrations in a human lung epithelial cell line. Sixty-seven RSV isolates from previously healthy infants (38 hospitalized for acute RSV infection (severe disease) and 29 never requiring hospitalization (mild disease)) were inoculated into A549, lung epithelial cells at precisely controlled, low multiplicity of infection to mimic natural infection. Cultures were evaluated at 48 hours, 60 hours, and 72 hours to evaluate area under the curve (AUC) cytokine/chemokine induction.

Results

Cells infected with isolates from severely ill infants produced higher mean concentrations of all cytokine/chemokines tested (IL-1α, IL-6, IL-8 and RANTES) at all-time points tested. RSV isolates collected from infants with severe disease induced significantly higher AUCIL-8 and AUCRANTES secretion in infected cultures than mild disease isolates (p=0.028 and p=0.019 respectively). IL-8 and RANTES concentrations were 4 times higher at 48 hours for these severely ill infant isolates. Additionally, 38 isolates were evaluated at all-time points for quantity of virus. RSV concentration significantly correlated with both IL-8 and RANTES at all-time points. Neither cytokine/chemokine concentrations nor RSV concentrations were associated with RSV subgroup.

Discussion

Infants’ RSV disease severity differences may be due in part to intrinsic viral strain-specific characteristics.

Risk of respiratory syncytial virus infection in infants with congenital cystic lung disease

BACKGROUND

Congenital cystic lung disease (CCLD), which includes congenital cystic adenomatoid malformation, bronchopulmonary sequestration, and congenital lobar emphysema, has been reported to increase the risk of recurrent respiratory infection. In particular, respiratory syncytial virus (RSV) causes severe lower respiratory tract disease in high-risk infants. The objective of this study was to investigate the risk of severe RSV infection in infants with CCLD.

METHODS

Infants antenatally diagnosed as having CCLD and admitted to a neonatal intensive care unit at the National Center for Child Health and Development in Tokyo between September 2002 and October 2011 were included in this study. We investigated retrospectively whether the infants were hospitalized with RSV infection by 24 months of age using their medical records.

RESULTS

Forty-eight infants were antenatally diagnosed as having CCLD. Of the 48 infants, four (8.3%) were hospitalized with RSV infection by 24 months of age.

CONCLUSIONS

Infants with CCLD have increased risk of severe RSV infection.

Titanium dioxide nanoparticles exacerbate pneumonia in respiratory syncytial virus (RSV)-infected mice

To reveal the effects of TiO2 nanoparticles, used in cosmetics and building materials, on the immune response, a respiratory syncytial virus (RSV) infection mouse model was used. BALB/c mice were exposed once intranasally to TiO2 at 0.5mg/kg and infected intranasally with RSV five days later. The levels of IFN-γ and chemokine CCL5, representative markers of pneumonia, in the bronchoalveolar lavage fluids of RSV-infected mice had increased significantly in TiO2-exposed mice compared with the control on day 5 post-infection, but not in uninfected mice. While pulmonary viral titers were not affected by TiO2 exposure, an increase in the infiltration of lymphocytes into the alveolar septa in lung tissues was observed. Immunohistochemical analysis revealed aggregation of TiO2 nanoparticles near inflammatory cells in the severely affected region. Thus, a single exposure to TiO2 nanoparticles affected the immune system and exacerbated pneumonia in RSV-infected mice.