Are late preterm infants as susceptible to RSV infection as full term infants?

PROTEA study: a protocol for a randomised controlled trial evaluating the efficacy, immune effects and cost-effectiveness of oral bacterial lysate therapy to protect moderate-late preterm infants from respiratory tract infections and wheezing

Infants, children and adults born moderate-late preterm (after 30-36 weeks of pregnancy) are at increased risk of respiratory infections, wheezing and lower lung function leading to increased medication use and hospitalisation. Risk factors frequently present in this population are, at least in part, associated with (lack of) exposure to microbes and subsequent perturbations in microbiome and immune system development. This manuscript presents the protocol of the double-blinded randomised placebo-controlled PROTEA trial, which will demonstrate whether treatment with immunomodulatory bacterial lysates (OM-85) can reduce lower respiratory tract infections and wheeze in the first year of life. The follow-up PROTEA-2 trial will identify possible carry-over effects of OM-85 treatment and investigate the clinical effect of continued treatment in the second year of life. Infants included are otherwise healthy infants born after 30-36 weeks of gestation, excluding those small for gestational age (<3rd percentile). They are recruited shortly after birth in 22 medical centres in the Netherlands. Participants will take OM-85 or placebo starting from 6-10 weeks of life till age 1 year (PROTEA study) or 2 years (PROTEA-2 study) and are closely monitored regarding respiratory health through e-applications. Biological samples, lung function measurements and detailed information on covariates will be collected at ages 2, 6, 12 and 24 months. Biological samples will aid in estimating the impact of bacterial lysate administration on immune cell composition, activation and maturation, vaccination responses, and microbiome diversity and maturation. Participant recruitment started in March 2022.

Surfactant Protein-A and its immunomodulatory roles in infant respiratory syncytial virus infection: a potential for therapeutic intervention?

The vast majority of early-life hospital admissions globally highlight respiratory syncytial virus (RSV), the leading cause of neonatal lower respiratory tract infections, as the major culprit behind the poor neonatal outcomes following respiratory infections. Unlike those of older children and adults, the immune system of neonates looks rather unique, therefore mostly counting on the innate immune system and antibodies of maternal origins. The collaborations between cells and immune compartments during infancy inclines bias toward a T-helper 2 (Th2) immune profile and thereby away from a T-helper 1 (Th1) immune response. What makes it more problematic is that RSV infection also tends to elicit a stronger Th2-biased immune response and drive an aberrant allergy-like inflammation. It is thus evident how RSV infections potentially pave the way for wheezing recurrences and childhood asthma later in life. Surfactant, the essential lung substance for normal breathing processes in mammals, has immunomodulatory properties including lung collectins such as Surfactant Protein-A (SP-A), which is the most abundant protein component of surfactant, and also Surfactant Protein-D (SP-D). Deficiency of SP-A and SP-D has been found to be associated with impaired pathogen clearance and exacerbated immune responses during infections. We therefore conducted a review of the literature to describe pathomechanisms of RSV infections during blunted neonatal immunity potentially facilitating allergy-like inflammatory events within the developing lungs and highlight the potential protective role of the humoral collectin SP-A to mitigate these in the "early in life" pulmonary immune system.

The developing immune system in preterm born infants: From contributor to potential solution for respiratory tract infections and wheezing

Moderate-late preterm-born infants experience more frequent and severe respiratory tract infections and wheezing compared to term-born infants. Decreasing the risk on respiratory tract infections and wheezing in this group is vital to improve quality of life and reduce medical consumption during infancy, but also to reduce the risk on asthma and COPD later in life. Until now, moderate-late preterm infants are underrepresented in research and mechanisms underlying their morbidity are largely unknown, although they represent 80% of all preterm-born infants. In order to protect these infants effectively, it is essential to understand the role of the immune system in early life respiratory health and to identify strategies to optimize immune development and respiratory health. This review elaborates on risk factors and preventative measures concerning respiratory tract infections and wheezing in preterm-born infants, exploring their impact on the immune system and microbiome. Factors discussed are early life antibiotic use, birth mode, feeding type and living environment. Further, differences in adaptive and innate immune maturation between term and preterm infants are discussed, as well as differences in local immune reactions in the lungs. Finally, preventative strategies are being explored, including microbiota transplantation, immune modulation (through pre-, pro-, syn- and postbiotics, bacterial lysates, vaccinations, and monoclonal antibodies) and antibiotic prophylaxis.

Acute viral bronchiolitis phenotype in response to glucocorticoid and bronchodilator treatment

OBJECTIVE

To analyze whether infants admitted to hospital with Acute Viral Bronchiolitis (AVB), who received glucocorticoids and bronchodilators, and who had an atopic phenotype, spent less time in hospital and/or less time on oxygen therapy when compared to those who did not have the phenotype.

METHOD

A cross-sectional, retrospective epidemiological study was developed with data from medical records of infants admitted to hospital due to AVB from 2012 to 2019 in a sentinel public hospital. It was verified that the frequency of prescription of glucocorticoids, bronchodilators and antibiotics. Length of stay and oxygen therapy duration were then compared in the group that used glucocorticoids and bronchodilators between those who had a personal or family history of atopy and those who did not. Subsequently, the length of hospital stay was compared among infants who received antibiotic therapy and those who did not.

RESULTS

Fifty-eight infants were included. Of these, 62.1 % received an antibiotic, 100 % a bronchodilator and 98.3 % a glucocorticoid. When comparing infants without a family history of atopy, those who received antibiotics had a longer hospital stay (p = 0.01).

CONCLUSION

The presence of an atopic phenotype did not interfere with the length of stay and/or oxygen therapy duration of those who received bronchodilators and glucocorticoids. Increased length of stay of infants without a family history of atopy, who used antibiotics without evidence of bacterial co-infection, and the high frequency of prescription of non-recommended drugs call attention to stricter protocol implementation and professional training in AVB diagnosis and care.

Correlation of gestational age and age at death in sudden infant death syndrome: another pointer to the role of critical developmental period?

BACKGROUND

Filiano and Kinney proposed a triple-risk model for the sudden infant death syndrome (SIDS) that involves the intersection of three risks: (1) a vulnerable infant, (2) a critical developmental period in homeostatic control, and (3) an exogenous stressor(s). The primary evidence for the role of a critical developmental period in SIDS etiology is the peak of cases around the third month of life. Independently, several studies pointed to correlation between gestational age and age at death in SIDS, but used that to assess the SIDS risk for preterm infants, ignoring further ramifications.

METHODS

We did a detailed analysis of CDC data spanning over two decades (1983-2011). We focused not only on the correlation between two age variables (gestational and age at death), but also on the possibility of misdiagnosis. Also, we attempted to account for potential biases in the data induced by the ICD-9/ICD-190 transition or the "Back to Sleep" campaign.

RESULTS

The peak of deaths in the third month of life, that was the main argument for the role of the critical development period, wasn't unique to SIDS. However, we confirmed an almost linear and negative correlation between gestational age and the week of death due to SIDS. This pattern (slope of correlation < 0 and significance of correlation p < 0.05) is characteristic of SIDS among all diseases analyzed in the study.

CONCLUSIONS

We interpret the results as the evidence of the role of the critical development period in SIDS etiology. Possibly more attention in the future research should be put to theories that are based on homeostatic control.

Utilization of Biopolymer-Based Lutein Emulsion as an Effective Delivery System to Improve Lutein Bioavailability in Neonatal Rats

Newborns' eyes and brains are prone to oxidative stress. Lutein has antioxidant properties and is the main component of macular pigment essential for protecting the retina, but has low bioavailability, thereby limiting its potential as a nutritional supplement. Oil-in-water emulsions have been used as lutein delivery systems. In particular, octenylsuccinated (OS) starch is a biopolymer-derived emulsifier safe to use in infant foods, while exhibiting superior emulsifying capacity. This study determined the effects of an OS starch-stabilized lutein emulsion on lutein bioavailability in Sprague-Dawley neonatal rats. In an acute study, 10-day-old pups received a single oral dose of free lutein or lutein emulsion, with subsequent blood sampling over 24 h to analyze pharmacokinetics. The lutein emulsion group had a 2.12- and 1.91-fold higher maximum serum lutein concentration and area under the curve, respectively, compared to the free lutein group. In two daily dosing studies, oral lutein was given from postnatal day 5 to 18. Blood and tissue lutein concentrations were measured. The results indicated that the daily intake of lutein emulsion led to a higher lutein concentration in circulation and key tissues compared to free lutein. The OS starch-stabilized emulsion could be an effective and safe lutein delivery system for newborns.

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

INTRODUCTION

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Mucosal Immune Responses to Respiratory Syncytial Virus

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

Neonatal Infection Due to SARS-CoV-2: An Epidemiological Study in Spain

Objective: Coronavirus disease 2019 (COVID-19) cases caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to increase worldwide. Although some data from pediatric series are available, more evidence is required, especially in neonates, a group with specific characteristics that deserve special attention. This study aimed to describe general and clinical characteristics, management, and treatment of postnatal-acquired (community and nosocomial/hospital-acquired) COVID-19 neonatal cases in Spain. Methods: This was a national prospective epidemiological study that included cases from a National Registry supported by the Spanish Society of Neonatology. Neonates with postnatal SARS-CoV-2 infection were included in this study. General data and infection-related information (mode and source of transmission, age at diagnosis, clinical manifestations, need for hospitalization, admission unit, treatment administered, and complementary studies performed, hospital stay associated with the infection) were collected. Results: A total of 40 cases, 26 community-acquired and 14 nosocomial were registered. Ten were preterm newborns (2 community-acquired and 8 nosocomial COVID-19 cases). Mothers (in both groups) and healthcare workers (in nosocomial cases) were the main source of infection. Hospital admission was required in 22 community-acquired cases [18 admitted to the neonatal intermediate care unit (NIMCU) and 4 to the neonatal intensive care unit (NICU)]. Among nosocomial COVID-19 cases (n = 14), previously admitted for other reasons, 4 were admitted to the NIMCU and 10 to the NICU. Ten asymptomatic patients were registered (5 in each group). In the remaining cases, clinical manifestations were generally mild in both groups, including upper respiratory airways infection, febrile syndrome or acute gastroenteritis with good overall health. In both groups, most severe cases occurred in preterm neonates or neonates with concomitant pathologies. Most of the cases did not require respiratory support. Hydroxychloroquine was administered to 4 patients in the community-acquired group and to 2 patients in the nosocomial group. Follow-up after hospital discharge was performed in most patients. Conclusions: This is the largest series of COVID-19 neonatal cases in Spain published to date. Although clinical manifestations were generally mild, prevention, treatment, and management in this group are essential.

The impact of respiratory viruses on lung health after preterm birth

Children born preterm, less than 37 weeks' gestation, are at increased risk of viral respiratory infections and associated complications both during their initial birth hospitalisation and in their first years following discharge. This increased burden of viral respiratory infections is likely to have long term implications for lung health and function in individuals born preterm, particularly those with bronchopulmonary dysplasia. Several hypotheses have been put forward to explain the association between early life viral respiratory infection and development of suboptimal lung health and function later in life following preterm birth. Although preterm infants with diminished lung function, particularly small airways, might be particularly susceptible to asthma and wheezing disorders following viral infection, there is evidence that respiratory viruses can activate number of inflammatory and airway re-modelling pathways. Therefore, the aim of this review is to highlight the perinatal and early life risk factors that may contribute to increased susceptibility to viral respiratory infections among preterm infants during early life and to understand how respiratory viral infection may influence the development of abnormal lung health and function later in life.

Assessing Variation in the Cost of Palivizumab for Respiratory Syncytial Virus Prevention in Preterm Infants

BACKGROUND

The variability in cost of palivizumab treatment, indicated for prevention of respiratory syncytial virus (RSV) infections in high-risk infants, has not been robustly estimated in prior studies. This study aimed to determine the cost variations of palivizumab from a US payer perspective for otherwise healthy preterm infants born 29-35 weeks gestational age (wGA) using infant characteristics and applied dosing regimens.

METHODS

Fenton Growth Charts were merged with World Health Organization Child Growth Standards to estimate preterm infant growth patterns. The merged growth chart was applied to infants who received palivizumab from a prospective, observational registry to determine future body weight using each infant's wGA and birth weight. Using quarter 3 (Q3) 2016-Q2 2017 vial cost, treatment costs at monthly dosing intervals were estimated using expected weights and averaged by age to derive expected mean 2016-2017 RSV seasonal costs per infant under various dosing scenarios.

RESULTS

Given different dosing scenarios (two to five doses), birth month, and growth patterns for preterm infants 29-35 wGA, the estimated average 2016-2017 seasonal cost of palivizumab treatment ranged from $3221 to $12,568. Outpatient-only cost (excluding first dose at hospital discharge) ranged from $1733 to $11,862. The main drivers of costs were dosing regimen (74% of variance), dosing interacted with birth month (17%), and wGA (6%).

CONCLUSION

The considerable variability in the average cost of palivizumab treatment for preterm infants is driven by choice of dosing regimen, wGA, and birth month. Therefore, when estimating the cost of palivizumab, it is important to consider both infant characteristics at each dose and potential dosing regimens.

Product review on the monoclonal antibody palivizumab for prevention of respiratory syncytial virus infection

Respiratory syncytial virus (RSV) accounts for about 20% of all respiratory infections in children below the age of 5 y. It is associated with up to 63% of all acute respiratory infections and up to 81% of all viral lower respiratory tract infections causing hospitalization in infants and young children. RSV leads to seasonal epidemics between November and April in the northern hemisphere. Most severe infections (RSV accounts for 50 to 80% of all cause bronchiolitis) affect infants younger than 6 months of age and high-risk infants including those born preterm with or without bronchopulmonary dysplasia and those with hemodynamically significant congenital heart disease up to an age of 24 months. Palivizumab, a highly potent RSV-neutralizing monoclonal antibody (Mab), has been licensed in 1998 for prophylactic use to prevent RSV associated hospitalizations in high-risk infants. This Mab is given by monthly intramuscular injection at a dose of 15 mg/kg over the RSV season (up to 5 times). Palivizumab proved to be safe and well-tolerated in this population. Concerns have been raised regarding cost-effectiveness of palivizumab and thus, palivizumab prophylaxis is mainly limited to selected high-risk infants for the first RSV season. Long-lasting Mabs will be the next future approach in the prophylaxis of RSV hospitalization until a vaccine is developed.

Evaluation of pulmonary functions in preschool children born late-preterm

AIM

The aim of this study was to evaluate the pulmonary functions of preschool children born late-preterm.

MATERIAL AND METHODS

Children aged between 3-7 years who were born at 340/7-366/7 weeks' gestation represented the target sample. Patients with a diagnosis of congenital cardiac, pulmonary and/or muscle diseases were excluded. Respiratory symptoms were evaluated using the modified asthma predictive index and International Study of Asthma and Allergies in Childhood criteria for children aged under and over 6 years, respectively. Skin prick tests were performed. Age-matched healthy controls were chosen according to the criteria proposed by the American Thoracic Society. Lung functions were evaluated using impulse oscillometry study in both groups. Data were recorded in the SPSS program.

RESULTS

A total of 139 late-preterms and 75 healthy controls participated in the study. The mean gestational week of the late-preterms was 35.3±0.9 weeks. The main admission diagnosis to neonatal intensive care unit was respiratory distress. In the postdischarge period, 54.1% were hospitalized for pulmonary infections at least once, and 57.8% were passive smoking currently. Aeroallergen sensitivity was detected as 25.8% in the late-preterm group; 34.5% and 15.1% were diagnosed as having asthma and non-asthmatic atopy, respectively. Impulse oscillometry study parameters of R5, R10, and Z5 were higher and X10 and X15 were lower in late-preterms than in controls (p<0.05). Late-preterms with and without respiratory distress in the postnatal period revealed no statistical differences for any parameters.

CONCLUSIONS

Our findings suggest that presence of increased peripheral airway resistance in late-preterms as compared to term-born controls.

Efficacy of palivizumab prophylaxis on the frequency of RSV-associated lower respiratory tract infections in preterm infants: determination of the ideal target population for prophylaxis

Respiratory syncytial virus (RSV) prophylaxis in high-risk infants is an effective intervention for the prevention of severe disease. The aim of this study was to determine the ideal target preterm population that might benefit from palivizumab prophylaxis by establishing the main risk factors for acute RSV-related infections. Former premature infants born with a gestational age ≤37 weeks and ≤1 year of age at the beginning of the RSV season and admitted with respiratory infection were included. RSV status was evaluated by RSV strip test in all infants. RSV-positive and -negative infants were compared in terms of demographic features, risk factors, requirement of hospitalisation and palivizumab administration. A total of 202 preterm infants under 1 year of age were enrolled. The RSV test was positive in 34 (16.8%) infants. Maternal age was significantly lower in RSV-positive infants compared with RSV-negative infants (p = 0.03). RSV-positive infants were found to be significantly discharged during the RSV season (p = 0.03). RSV-positive infants required significantly higher rates of hospitalisation and need for mechanical ventilation. Of the RSV-positive infants, 28 (82%) had a gestational age ≥29 weeks. Seventeen (77%) RSV-positive infants that required hospitalisation were ≥29 weeks of gestation. All infants with a gestational age ≥29 weeks and without palivizumab prophylaxis developed RSV infection. Palivizumab prophylaxis should be implemented into guidelines to cover preterm infants with a gestational age >29 weeks. Palivizumab prophylaxis should also be considered in high-risk infants ≤6 months of age during the RSV season.

Viral Lower Respiratory Tract Infections

Lower respiratory tract infections in children are often viral in origin. Unfortunately in this time of significant antimicrobial resistance of infectious organisms, especially bacteria, there is still a tendency for clinicians to manage a child who coughs with antibiotics. In addition, the World Health Organization (WHO) has defined “pneumonia” as a condition that only occurs in children who have “fast breathing or chest wall indrawing”. That would delineate upper respiratory tract infections from those in the lower airway. However, in addition to pneumonia another important entity exists in the lower respiratory tract that is almost always viral in origin. This condition is acute viral bronchiolitis. The concept of “acute lower respiratory tract infection” (ALRTI) has emerged and it is becoming increasing evident from a number of studies that the infectious base of both acute pneumonia (AP) and acute bronchiolitis in children has a mixed etiology of microorganisms. Therefore, whilst certain clinical phenotypes do not require antibiotics the actual microbial etiology is much less distinct.

Oxidative Stress Related Diseases in Newborns

We review oxidative stress-related newborn disease and the mechanism of oxidative damage. In addition, we outline diagnostic and therapeutic strategies and future directions. Many reports have defined oxidative stress as an imbalance between an enhanced reactive oxygen/nitrogen species and the lack of protective ability of antioxidants. From that point of view, free radical-induced damage caused by oxidative stress seems to be a probable contributing factor to the pathogenesis of many newborn diseases, such as respiratory distress syndrome, bronchopulmonary dysplasia, periventricular leukomalacia, necrotizing enterocolitis, patent ductus arteriosus, and retinopathy of prematurity. We share the hope that the new understanding of the concept of oxidative stress and its relation to newborn diseases that has been made possible by new diagnostic techniques will throw light on the treatment of those diseases.

Evaluation of recent New Vaccine Surveillance Network data regarding respiratory syncytial virus hospitalization rates in US preterm infants

In July 2014, the Committee on Infectious Diseases (COID) updated their guidance on the use of palivizumab, recommending against use in preterm infants 29 to 35 weeks' gestational age (wGA). A primary data source cited to support this significant change was the low respiratory syncytial virus (RSV) hospitalization rate observed in the subpopulation of preterm (<37 wGA) infants evaluated from 2000 to 2005 through the New Vaccine Surveillance Network (NVSN). Here we critically appraise the preterm infant data from the NVSN in the context of data regarding the use of palivizumab in this same time period. Data from the NVSN, an analysis of Florida Medicaid data, and a national survey of US in-hospital palivizumab administration demonstrated that during 2001 to 2007, palivizumab was administered to 59% to 83% of preterm infants born at <32 wGA and 21% to 27% of all preterm infants (<37 wGA). When the NVSN data regarding incidence of RSV hospitalization in preterm infant subgroups were evaluated as a function of chronologic age, preterm infants <32 wGA showed a paradoxical increase in RSV hospitalization with older age, with the highest risk of RSV hospitalization occurring at 18 to 23 months of age. This pattern is most consistent with a reduction in RSV hospitalizations in <32 wGA infants in the first 12 to 18 months of life due to high palivizumab use at these young ages. The NVSN data were not designed to and cannot accurately describe RSV disease burden in preterm infants given the small size of the analyzed subpopulation and the high use of palivizumab during the study period.

Evaluation of lung function on impulse oscillometry in preschool children born late preterm

BACKGROUND

There is a paucity of data on lung physiology in late-preterm children, who may be exposed to a risk of decline in lung function during childhood. In this study, we evaluated lung function in preschool children born late preterm using impulse oscillometry (IOS), and compared the results with those obtained in healthy term-born children.

METHODS

Children between 3 and 7 years of age who were born late preterm and who were being followed up at the outpatient clinic were included as the late-preterm group. Age-matched healthy term-born children served as controls. A total of 90 late-preterm and 75 healthy children were included in the study. At 5-20 Hz, resistance (R5-R20), reactance (X5-X20), impedans (Z5) and resonant frequency were measured on IOS.

RESULTS

Mean IOS R5 and R10 were significantly higher in the late-preterm group than in the control group (P < 0.05). Mean R5, R10 and Z5 were statistically higher in late-preterm children who had been hospitalized for pulmonary infection compared with the control group (P < 0.05). Mean R5, R10, R15, R20 and Z5 were significantly higher, and mean X10 and X15 significantly lower in late-preterm children with passive smoking compared with late-preterm children without passive smoking and controls (P < 0.05).

CONCLUSION

Children born late preterm had signs of peripheral airway obstruction on IOS-based comparison with healthy term-born controls. Besides the inherent disadvantages of premature birth, hospitalization for pulmonary infection and passive smoking also seemed to adversely affect lung function in children born late preterm.

Prematurity and the burden of influenza and respiratory syncytial virus disease

BACKGROUND

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

DATA SOURCES

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

RESULTS

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

CONCLUSIONS

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

RSV: Immunoprophylaxis and non-invasive respiratory support in ex-preterms: A northern UK perspective

Recent guidance has suggested that immunoprophylaxis with monoclonal antibody against respiratory syncytial virus (RSV) should be extended to ex-preterm infants who are moderate-to-late-preterm and discharged home during the RSV season. Noninvasive respiratory support (NIV) for infants with bronchiolitis is becoming widespread with little supporting evidence for efficacy over nonpressure support methods. We used multicentre prospective audit and service evaluation to evaluate whether extension of current practice in line with the guidance would provide a clinical or cost benefit, and whether NIV provides any benefits in the ex-preterm population. The prevalence of bronchiolitic illness requiring admission in our population was similar to other studies (2.5%). We found that the majority of ex-preterm infants with RSV positive bronchiolitis who required NIV did not meet the extended criteria for immunisation. Our data suggest that extending RSV prophylaxis as recommended would be unlikely to reduce numbers of infants requiring respiratory support for RSV. NIV use has been widely adopted (9% of 'bronchiolitic' admissions) in our region but the data do not support it as a useful adjunct for ex-preterms with RSV positive illness requiring respiratory support: it does not appear to reduce the need for subsequent formal ventilation. Our study does not support a case for change to more widespread, protocol driven immunisation for RSV. Further research is needed in a randomised, controlled setting to examine the use of NIV in bronchiolitis in a wider context.

Risk of respiratory syncytial virus infection in preterm infants: reviewing the need for prevention

Premature infants are at substantial risk for a spectrum of morbidities that are gestational age dependent. Respiratory syncytial virus (RSV) infection is most common in the first two years of life with the highest burden in children aged <6 months. Preterm infants ≤35 weeks' gestation are handicapped by incomplete immunological and pulmonary maturation and immature premorbid lung function with the added risk of bronchopulmonary dysplasia. Superimposed RSV infection incites marked neutrophilic airway inflammation and innate immunological responses that further compromise normal airway modeling. This review addresses the epidemiology and burden of RSV disease, focusing on the preterm population. Risk factors that determine RSV-disease severity and hospitalization and the impact on healthcare resource utilization and potential long-term respiratory sequelae are discussed. The importance of disease prevention and the evidence-based rationale for prophylaxis with palivizumab is explored, while awaiting the development of a universal vaccine.

Hospital admission due to respiratory viral infections in moderate preterm, late preterm and term infants during their first year of life

Background

Respiratory viral infections are a major cause of hospitalisation in infants <1 year and might cause severe symptoms in preterm infants. Our aim was to analyse admissions due to respiratory infections in moderate, late and term infants, and to identify risk factors for hospitalisation in preterm versus term.

Methods

Prospective study in a cohort of moderate and late preterm, and term infants born between October/2011 and December/2012. Admissions due to respiratory infections during the first year of life were analysed and compared among moderate (32–33), late (34–36) and term infants. Sixteen respiratory viruses were detected by RT-PCR. Clinical data were collected.

Results

30 (20.9%) out of 143 preterm infants required admission for respiratory infection, versus 129 (6.9%) of 1858 term infants born in the same period (p < 0.0001, OR: 3.6 CI 2.0 to 5.0). Hospitalised children had a higher prevalence of hyaline membrane disease (HMD) at birth (p < 0.001, OR: 7.7 CI: 2.121 to 27.954) and needed more mechanical ventilation (p < 0.001, OR: 5.7 CI: 1.813 to 18.396). Virus was identified in 25/30 (83%) preterm babies, and in 110/129 (85%) term infants. The most frequent viruses in preterm infants were RSV (76%) rhinovirus (20%). Clinical and epidemiological characteristics among term and preterm infants were similar.

Conclusions

The risk of respiratory admissions during the first year of life is up to 3.6 times higher in moderate and late preterm. Once admitted, clinical features of respiratory episodes requiring hospitalisation are similar among term and preterm infants. Hyaline membrane disease and mechanical ventilation were also risk factors for respiratory admissions.

RSV infection among children born moderately preterm in a community-based cohort

We aimed to determine the rates of proven respiratory syncytial virus (RSV) hospitalization and disease severity among children born moderately preterm (MP, gestational age [GA] 32-36 weeks, n = 964), children born full-term (FT, GA 38-42 weeks, n = 572), and children born early preterm (EP, GA <32 weeks, n = 524). Our second aim was to identify risk factors for RSV hospitalization among MP. We extracted data from parental questionnaires and medical records, retrieved from a community-based cohort of children aged 43-49 months. The RSV hospitalization rates of MP were higher than FT (3.9 vs. 1.2 %, relative rate 3.2; 95 % confidence interval (CI) 1.4-7.1) and equal to EP (3.9 vs. 3.2 %, relative rate 1.2; 95 % CI 0.7-2.1). MP were hospitalized at an earlier age than EP. Disease severity (based on the type of treatment and hospitalization length) was equal in all groups. Risk factors for RSV hospitalization in MP were younger age and lower birth weight. In multivariable analyses, shorter GA and passive smoking independently increased the likelihood of RSV hospitalization in MP.

CONCLUSION

The rates of hospitalization due to proven RSV infection are higher in MP than FT and not different between MP and EP. No difference in disease severity was observed. Among MP, the rates of RSV hospitalization are higher for lower GA and when exposed to passive smoking.

Effects of blue light phototherapy on DNA integrity in preterm newborns

In previous studies, exposure to phototherapy, but not oxygen therapy, resulted in damage to genetic material in newborns. The objective of this study was to determine whether micronucleated erythrocytes (MNE) increased in preterm newborns (PNBs) who were exposed to blue light phototherapy lamps. MNE of mature organisms are rapidly eliminated by the spleen, and the presence of MNE has been related to immaturity in some species. Furthermore, PNBs present spontaneous MNE. Blood samples were taken from 17 PNBs at birth to establish baseline frequencies (0 h). After beginning blue light phototherapy, blood samples were obtained from 11 of these PNBs at 24-h intervals for 96 h, after the baseline sample. MNE and micronucleated polychromatic erythrocytes (MNPCE) were counted. The basal values of MNE and MNPCE from 17 PNBs were 0.62 ± 0.48 and 1.52 ± 1.28 (‰), respectively, and no increase in MNE or MNPCE was observed in the serial samples of 11 PNBs exposed to blue light and oxygen therapies, though previous studies reported increases using other types of lamps. In conclusion, under the conditions described no increase in the number of MNE or MNPCE was observed in the peripheral blood of PNBs exposed to blue light phototherapy.

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

ABSTRACT: 

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

Respiratory disorders in moderately preterm, late preterm, and early term infants

Even when it is just a few weeks before term gestation, early birth has consequences, resulting in higher morbidity and mortality. Respiratory issues related to moderate prematurity include delayed neonatal transition to air breathing, respiratory distress resulting from delayed fluid clearance (transient tachypnea of the newborn), surfactant deficiency (respiratory distress syndrome), and pulmonary hypertension. Management approaches emphasize appropriate respiratory support to facilitate respiratory transition and minimize iatrogenic injury. Studies are needed to determine the impact of respiratory distress coupled with mild-moderate prematurity on long-term outcome.

Moderately preterm children have more respiratory problems during their first 5 years of life than children born full term

RATIONALE

Pulmonary outcomes of moderate-preterm children (MP) are unknown.

OBJECTIVES

To investigate the prevalence of respiratory symptoms during infancy and at preschool age of MP compared with full-term (FT) and early preterm children (EP) and to determine factors associated with respiratory symptoms of MP at school age.

METHODS

Prospective cohort study.

OUTCOME VARIABLES

number of rehospitalizations caused by respiratory problems, prevalence of respiratory symptoms determined by ISAAC Questionnaires, and factors associated with respiratory symptoms determined by univariate and multivariate analyzes.

MEASUREMENTS AND MAIN RESULTS

A total of 988 MP, 551 EP, and 573 FT children were included. The number of hospitalizations caused by respiratory problems during the first year of life was doubled in MP compared with FT (6% vs. 3%; P < 0.001). At preschool age, compared with FT, MP reported more cough or wheeze during a cold (63% vs. 50%; P < 0.001); cough or wheeze without a cold (23% vs. 15%; P = 0.001); nocturnal cough (33% vs. 26%; P = 0.005); dyspnea (8% vs. 4%; P = 0.011); and use of medication (inhaled steroids, 9% vs. 6%; P = 0.042) (antibiotics, 12% vs. 7%; P = 0.002). Factors associated with respiratory symptoms at 5 years among MP were respiratory problems, eczema, rehospitalization in infancy, passive smoking in infancy, family history of asthma, and higher social class. Multivariate analyzes showed the same results except for rehospitalization in infancy.

CONCLUSIONS

MP have more respiratory symptoms than FT during early childhood. Factors associated with respiratory symptoms at school age are early respiratory problems, family history of asthma, higher social class, and passive smoking.

Severe bronchiolitis in infants born very preterm and neurodevelopmental outcome at 2 years

Preterm infants are at greater risk of bronchopulmonary dysplasia, which is associated with neurodevelopmental impairment. These infants are also more likely to develop severe bronchiolitis, which can contribute to neurodevelopmental impairment. The aim of this study was to determine whether severe bronchiolitis in very preterm infants (born before 33 weeks of gestation) was associated with an increased risk of neurodevelopmental impairment at 2 years of age. We analyzed a population-based cohort of infants (the Loire Infant Follow-up Team cohort) born between 1 January 2003 and 31 December 2009. Severe bronchiolitis was defined as hospitalization due to bronchiolitis during the first year of life. Neurodevelopmental outcome was assessed at 2 years of corrected age. A total of 2,405 infants were included in this analysis and categorized based on neonatal respiratory status: 1,308 (54.4 %) received no respiratory assistance, 864(35.9 %) received oxygen for <28 days, and 167 (6.9 %) had mild and 66 (2.7) moderate or severe bronchopulmonary dysplasia. At 2 years, 502 children displayed non-optimal neurodevelopmental outcome (20.9 %). Moderate or severe bronchopulmonary dysplasia was significantly associated with non-optimal neurodevelopmental outcome at 2 years (adjusted odds ratios (OR) = 2.3 [95 % confidence interval (CI): 1.3-3.9], p = 0.003). In the first year, 318 infants acquired severe bronchiolitis (13.2 %), which was not associated with non-optimal neurodevelopmental outcome (adjusted OR = 1.0 [95 % CI: 0.8-1.4]; p = 0.88). In conclusion, respiratory status in the neonatal period was significantly associated with non-optimal neurodevelopmental outcome at 2 years, while severe bronchiolitis was not.

Prolonged exclusive breastfeeding, autumn birth and increased gestational age are associated with lower risk of fever in children with hand, foot, and mouth disease

Epidemics of hand, foot, and mouth disease (HFMD) have been emerging and reemerging in recent years. This study aims to investigate whether breastfeeding and other factors may affect the profile of fever and disease course in children with HFMD. Three hundred seventy-two preschool children with HFMD were included. The demographics, environmental factors, and delivery- and feeding-associated factors in the children were obtained and their effects on the profile of fever and disease course were analyzed. Of the 372 children, 139 (37.37%) had fever during the disease course. Gender, breastfeeding pattern, birth season and gestational age were significantly different between the children with and without fever (p = 0.034, p < 0.0001, p = 0.035 and p = 0.013, respectively). After multivariate-adjusted analysis, prolonged exclusive breastfeeding (p = 0.001, OR 0.401, 95% CI 0.229-0.704), autumn birth (p = 0.007, OR 0.409, 95% CI 0.214-0.784) and higher gestational age (p = 0.029, OR 0.089, 95% CI 0.010-0.781) were protective factors for the incidence of fever.

Late preterm birth: a review of medical and neuropsychological childhood outcomes

Late preterm (LP) birth (34 0/7 - 36 6/7 weeks' gestation) accounts for nearly three-fourths of all preterm births, making this population a sizeable public health concern. The immature fetal development associated with LP delivery increases the risk of mortality and short-term medical complications. Which combination of maternal, fetal, or neonatal risk factors may be most critical has only recently begun to be addressed, and whether LP birth's disruptive impact on brain development will exert adverse effects on neuropsychological functioning in childhood and adolescence has been understudied. Early data have shown a graded response, with LP children often functioning better than very preterm children but worse than term children, and with subtle intellectual and neuropsychological deficits in LP children compared with healthy children born at term gestational age. Further characterization of the neuropsychological profile is required and would be best accomplished through prospective longitudinal studies. Moreover, since moderate and LP births result in disparate medical and psychological outcomes, the common methodology of combining these participants into a single research cohort to assess risk and outcome should be reconsidered. The rapidly growing LP outcomes literature reinforces a critical principle: fetal development occurs along a dynamic maturational continuum from conception to birth, with each successive gestational day likely to improve overall outcome.

Health outcomes in infancy and childhood of moderate and late preterm infants

There has been a long-held belief that outcomes for babies born at moderate and late preterm gestations do not differ substantially from those of infants born at full term. This has recently been challenged by studies highlighting an increased risk of adverse neonatal outcomes, and of poorer cognitive, behavioural and educational outcomes in this population. Data about the effects of birth at moderate and late preterm gestations on later health outcomes are limited, but emerging evidence suggests that ongoing physical health may also be worse in those born just a few weeks before full term. This review summarises the available evidence, considers the factors influencing health outcomes and discusses the implications for the planning and provision of children's health care services.

Long term respiratory outcomes of late preterm-born infants

In recent years, the rate of preterm births has risen in many industrialised countries with late preterm births forming a substantial proportion of the preterm births. Late preterm infants are delivered at the immature saccular stage of lung development when surfactant and antioxidant systems are still developing. It is now increasingly recognised that late preterm infants have increased respiratory morbidity in the neonatal period. In addition, late preterm infants are at an increased risk of lower respiratory tract infections in infancy from respiratory viruses such as respiratory syncytial virus. There is a paucity of data reporting lung function in infancy and childhood in late preterm born children. The available data suggest that children born late preterm may be at risk of decreased lung function in later life. However, further studies are required to assess the medium and long term respiratory consequences of late preterm birth.