Lung function of preterm infants before and after viral infections

Reversible aberrancies in gut microbiome of moderate and late preterm infants: results from a randomized, controlled trial

The aim of this study was to obtain insight into the composition and function of the deviant gut microbiome throughout infancy in children born moderately and late preterm and their response to microbiome modulation. We characterized the longitudinal development of the gut microbiome from birth to the age of 12 months by metagenomic sequencing in 43 moderate and late preterm children participating in a randomized, controlled trial (ClinicalTrials.gov/no.NCT00167700) assessing the impact of a probiotic (Lactobacillus rhamnosus GG, ATCC 53,103, currently Lacticaseibacillus rhamnosus GG) and a prebiotic (galacto-oligosaccharide and polydextrose mixture, 1:1) intervention as compared to a placebo administered from 3 to 60 days of life. In addition, 9 full-term, vaginally delivered, breast-fed infants, who remained healthy long-term were included as references. Significant differences in taxonomy, but not in functional potential, were found when comparing the gut microbiome composition of preterm and full-term infants during the first month of life. However, the gut microbiome of preterm infants resembled that of full-term infants by 6 months age. Probiotic and prebiotic treatments were found to mitigate the shift in the microbiome of preterm infants by accelerating Bifidobacteria-dominated gut microbiome in beta diversity analysis. This study provides intriguing information regarding the establishment of the gut microbiome in children born moderately and late preterm, representing the majority of children born preterm. Specific pro- and prebiotics may reverse the proinflammatory gut microbiome composition during the vulnerable period, when the microbiome is low in resilience and susceptible to environmental exposure and simultaneously promotes immunological and metabolic maturation.

Dose-dependent impact of human milk feeding on tidal breathing flow-volume loop parameters across the first 2 years of life in extremely low-birth-weight infants: a cohort study

The purpose of this study is to test the hypothesis that higher consumption of human milk (HM) in preterm infants with birth weight (BW) <1000 g is associated with improved lung function in a dose-dependent manner over the first 2 years of corrected age (CA). This retrospective study at an academic medical center included infants with BW <1000g. They had lung function assessment by the tidal breathing flow-volume loop (TBFVL) follow-up visits at 0-3-, 3-6-, 6-12-, 12-18-, and 18-24-month CA. One hundred eighty infants were included in the study with a mean (SD) gestational age 26.5 (1.90) weeks and BW 772.4 (147.0) g, 50% were female, and 60% developed BPD. 62.8% of infants received HM during the NICU stay. According to a general linear model (including GA, being small for GA (SGA), sex, human milk percentage, sepsis, and BPD), on average, each week of GA resulted in a higher tPTEF/tE of 1.24 (p = 0.039) and being SGA in a lower tPTEF/tE of 5.75 (p = 0.013) at 0-3-month CA. A higher percentage of human milk out of the total enteral intake was associated with better tPTEF/tE z-scores at 0-3 months (p = 0.004) and 18-24 months of CA (p = 0.041). BPD diagnosis was associated with a relevantly worse tPTEF/tE z-score at 6-12 months of CA (p = 0.003).

CONCLUSION

Preterm infants with higher consumption of HM had significantly less airway obstruction across the first 2 years, suggesting that human milk may contribute in a dose-dependent manner to improve lung function in early childhood in former preterm infants born ELBW.

WHAT IS KNOWN

• Human milk feeding reduces the risk of prematurity-related morbidities, including necrotizing enterocolitis, sepsis, lower respiratory tract infections, and BPD. Both exclusive and partial human milk feeding appear to be associated with a lower risk of BPD in preterm infants.

WHAT IS NEW

• This cohort study of 180 preterm infants with birth weight < 1000 g found that exposure to human milk during hospitalization improves airway obstruction markers tPTEF/tE z-score over the first 2 years of corrected age in a dose-dependent manner.

Pre-notifications increase retention in a 17-year follow-up of adolescents born very preterm

OBJECTIVE

Retention is essential in follow-up studies to reduce missing data, which can cause bias and limit the generalizability of the results. We investigated whether pre-notification letters would increase the response rates of approval forms and questionnaires and reduce the need for post-notifications in a prospective follow-up study of 17-year-old adolescents.

STUDY DESIGN

and settings This long-term follow-up study included 269 adolescents were randomized (1:1) into a pre-notification group (n = 132) and a no pre-notification group (n = 137). The pre-notification letter was sent prior to the approval form and questionnaires. The outcome measures were the response rates to the approval forms and questionnaires and the rate of post-notifications required.

RESULTS

The adolescents who received the pre-notifications were more likely to return approval forms (n = 88/132, 67%) than the adolescents who did not receive the pre-notifications (n = 79/137, 58%) (OR 1.5, 95% CI 0.9-2.4). The rates of returned questionnaires were higher in the pre-notification group (n = 82/88, 93%) than in the no pre-notification group (n = 68/79, 86%) (OR 2.2, 95% CI 0.8-6.3). The adolescents who did not receive the pre-notifications were more likely to need the post-notifications than the adolescents who received the pre-notifications (OR 3.0, 95% CI 1.4 to 6.5).

CONCLUSIONS

Pre-notifications decreased the need for post-notifications and may increase retention in 17-year-old adolescents. Based on our findings, pre-notification letters are recommended in future follow-up studies in adolescents.

TRIAL REGISTRATION

The Ethics Review Committee of the Hospital District of South-West Finland approved the 17-year PIPARI Study protocol in January 2018 (23.1.2018; 2/180/2012). The study has been registered to the SWAT repository as SWAT 179. Filetoupload,1457904,en.pdf (qub.ac.uk).

Early origins of respiratory disease

Chronic respiratory morbidity is unfortunately common in childhood, particularly in those born very prematurely or with congenital anomalies affecting pulmonary development and those with sickle cell disease. Our research group, therefore, has focused on the early origins of chronic respiratory disease. This has included assessing antenatal diagnostic techniques and potentially therapeutic interventions in infants with congenital diaphragmatic hernia. Undertaking physiological studies, we have increased the understanding of the premature baby's response to resuscitation and evaluated interventions in the delivery suite. Mechanical ventilation modes have been optimised and randomised controlled trials (RCTs) with short- and long-term outcomes undertaken. Our studies highlighted respiratory syncytial virus lower respiratory tract infections (LRTIs) and other respiratory viral LRTIs had an adverse impact on respiratory outcomes of prematurely born infants, who we demonstrated have a functional and genetic predisposition to respiratory viral LRTIs. We have described the long-term respiratory outcomes for children with sickle cell disease and importantly identified influencing factors. In conclusion, it is essential to undertake long term follow up of infants at high risk of chronic respiratory morbidity if effective preventative strategies are to be developed.

Participant retention in follow-up studies of prematurely born children

Background

Follow-up studies of infants born prematurely are essential to understand the long-term consequences of preterm birth and the efficacy of interventions delivered in the neonatal period. Retention of participants for follow-up studies, however, is challenging, with attrition rates of up to 70%. Our aim was to examine retention rates in two follow-up studies of prematurely born children and identify participant or study characteristics that were associated with higher attrition, and to discuss retention strategies with regard to the literature.

Methods

Data from children recruited at birth to one of two studies of prematurely born infants were assessed. The two studies were the United Kingdom Oscillation Study (UKOS, a randomised study comparing two modes of neonatal ventilation in infants born less than 29 weeks of gestational age (GA)), and an observational study examining the impact of viral lower respiratory tract infections in infancy in those born less than 36 weeks of GA (virus study). The UKOS participants, but not those in the virus study, had regularly been contacted throughout the follow-up period. UKOS subjects were followed up at 11 to 14 years of age and subjects in the virus study at 5–7 years of age. At follow up in both studies, pulmonary function and respiratory morbidity were assessed. Retention rates to follow-up in the two studies and baseline characteristics of those who were and were not retained were assessed.

Results

Retention was significantly higher in UKOS than the virus study (61% versus 35%, p < 0.0001). Subjects lost to UKOS follow up had greater deprivation scores (p < 0.001), a greater likelihood of intrauterine tobacco exposure (p = 0.001) and were more likely to be of non-white ethnicity (p < 0.001). In the virus study, those lost to follow-up had higher birth weights (p = 0.036) and were less likely to be oxygen dependent at hospital discharge (p = 0.003) or be part of a multiple birth (p = 0.048).

Conclusions

Higher retention was demonstrated when there was regular contact in the follow-up period. Both social factors and initial illness severity affected the retention into follow-up studies of prematurely born infants, though these factors were not consistent across the two studies.

Paediatric Virology and respiratory syncytial virus: An interview with Honorary Senior Lecturer in Paediatric Infectious Diseases Dr Simon B. Drysdale (St. George's, University of London, UK)

Dr Simon B. Drysdale, Consultant and Honorary Senior Lecturer in Paediatric Infectious Diseases at St. George's University Hospitals NHS Foundation Trust and St. George's, University of London, is one of the most talented early career academic specialists in Paediatric Infectious Diseases in the United Kingdom. His main research interest is respiratory syncytial virus (RSV); he is particularly interested in understanding the host susceptibility to RSV, the management of RSV infection and associated health economics and the development of treatments and immunisations/vaccines, which are currently lacking. According to Dr Drysdale, RSV is a significant cause of morbidity and mortality among young infants and older adults, particularly those with co-morbidities. While there is ample RSV epidemiological and healthcare cost data available for young infants and children, more data is required for older children and adults. There are currently several antiviral medications for the treatment of RSV infection in development; however, none have yet progressed beyond Phase 2 clinical trials. Multiple types of novel therapeutic molecules have been developed, including fusion and non-fusion inhibitors and polymerase inhibitors aimed at various RSV targets, such as the F protein and RNA polymerase. In recent years, great strides have been made with regards to an RSV vaccine or monoclonal antibody, with >40 candidates currently in development. A maternal RSV vaccine, which just completed a Phase 3 trial, was shown to have 44% efficacy against hospitalization for RSV lower respiratory tract infection in infants. A new long-acting monoclonal antibody against RSV infection, having shown excellent promise in a Phase 2 trial in infants, is about to be investigated in a Phase 3 clinical trial commencing shortly.

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.

Predicting healthcare outcomes in prematurely born infants using cluster analysis

AIMS

Prematurely born infants are at high risk of respiratory morbidity following neonatal unit discharge, though prediction of outcomes is challenging. We have tested the hypothesis that cluster analysis would identify discrete groups of prematurely born infants with differing respiratory outcomes during infancy.

METHODS

A total of 168 infants (median (IQR) gestational age 33 (31-34) weeks) were recruited in the neonatal period from consecutive births in a tertiary neonatal unit. The baseline characteristics of the infants were used to classify them into hierarchical agglomerative clusters. Rates of viral lower respiratory tract infections (LRTIs) were recorded for 151 infants in the first year after birth.

RESULTS

Infants could be classified according to birth weight and duration of neonatal invasive mechanical ventilation (MV) into three clusters. Cluster one (MV ≤5 days) had few LRTIs. Clusters two and three (both MV ≥6 days, but BW ≥or <882 g respectively), had significantly higher LRTI rates. Cluster two had a higher proportion of infants experiencing respiratory syncytial virus LRTIs (P = 0.01) and cluster three a higher proportion of rhinovirus LRTIs (P < 0.001) CONCLUSIONS: Readily available clinical data allowed classification of prematurely born infants into one of three distinct groups with differing subsequent respiratory morbidity in infancy.

Phenotypical characterization of human rhinovirus infections in severely premature children

BACKGROUND

Human Rhinovirus (HRV) has been identified as the most common cause of acute respiratory infections and hospitalizations in premature children. It is unclear if premature children are more susceptible to HRV due to their decreased pulmonary reserve or because they have enhanced lower airway reactivity to HRV.

METHODS

We conducted a retrospective analysis of the clinical respiratory presentation of all PCR-confirmed HRV infections in full-term and premature children aged ≤3 years in our institution. Standardized respiratory distress scores were developed to examine lower airway obstruction (i.e., wheezing, hyperinflation, and sub-costal retractions) along with markers of decreased pulmonary reserve (hypoxemia and tachypnea) in young children with HRV infections. Demographic and clinical variables were obtained from reviewing electronic medical records (EMR).

RESULTS

This study included a total of 205 children; 71% of these children were born full-term (>37 weeks gestation), 10% preterm (32-37 weeks) and 19% severely premature (<32 weeks). Our results demonstrated that: 1) HRV infections in the first 3 years of life were associated with higher overall respiratory distress scores in severely premature children relative to children born preterm or full-term; 2) HRV-infected severely premature children ≤3 years old were more likely to have lower airway obstruction than HRV-infected children born preterm or full-term; and 3) other clinical signs of respiratory distress such as tachypnea and hypoxemia were not more common in severely premature than in preterm and full-term children during an HRV infection.

CONCLUSIONS

Our results indicate that HRV infections in severely premature children are associated with lower airway obstruction rather than hypoxemia or tachypnea. The latter suggests that enhanced airway reactivity is the underlying mechanism for the increased susceptibility to HRV in severely premature children. Longitudinal studies are needed to understand why premature babies develop airway hyper-reactivity to HRV and the long-term effects of early HRV infection in this population.

Respiratory viral infections in infancy and school age respiratory outcomes and healthcare costs

OBJECTIVES

To determine the impact of viral lower respiratory tract infections (LRTIs) in infancy including rhinovirus (RV) and infancy respiratory syncytial virus (RSV), on school age pulmonary function and healthcare utilization in prematurely born children.

WORKING HYPOTHESIS

School age respiratory outcomes would be worse and healthcare utilization greater in children who had viral LRTIs in infancy.

STUDY DESIGN

Prospective study.

SUBJECT SELECTION

A cohort of prematurely born children who had symptomatic LRTIs during infancy documented, was recalled.

METHODS

Pulmonary function was assessed at 5 to 7 years of age and health related costs of care from aged one to follow-up determined.

RESULTS

Fifty-one children, median gestational age 33⁺⁶ weeks, were assessed at a median (IQR) age 7.03 (6.37-7.26) years. Twenty-one children had no LRTI, 14 RV LRTI, 10 RSV LRTI, and 6 another viral LRTI (other LRTI). Compared to the no LRTI group, the RV group had a lower FEV₁ (P = 0.033) and the other LRTI group a lower FVC (P = 0.006). Non-respiratory medication costs were higher in the RV (P = 0.018) and RSV (P = 0.013) groups. Overall respiratory healthcare costs in the RV (£153/year) and RSV (£27/year) groups did not differ significantly from the no LRTI group (£56/year); the other LRTI group (£431/year) had higher respiratory healthcare costs (P = 0.042).

CONCLUSIONS

In moderately prematurely born children, RV and RSV LRTIs in infancy were not associated with higher respiratory healthcare costs after infancy. Children who experienced LRTIs caused by other respiratory viruses (including RV) had higher respiratory healthcare costs and greater pulmonary function impairment.

Paediatric Virology and its interaction between basic science and clinical practice (Review)

The 3rd Workshop on Paediatric Virology, which took place on October 7th, 2017 in Athens, Greece, highlighted the role of breast feeding in the prevention of viral infections during the first years of life. Moreover, it focused on the long-term outcomes of respiratory syncytial virus and rhinovirus infections in prematurely born infants and emphasised the necessity for the development of relevant preventative strategies. Other topics that were covered included the vaccination policy in relation to the migration crisis, mother‑to‑child transmission of hepatitis B and C viruses, vaccination against human papilloma viruses in boys and advances on intranasal live‑attenuated vaccination against influenza. Emphasis was also given to the role of probiotics in the management of viral infections in childhood, the potential association between viral infections and the pathogenesis of asthma, fetal and neonatal brain imaging and the paediatric intensive care of children with central nervous system viral infections. Moreover, an interesting overview of the viral causes of perinatal mortality in ancient Greece was given, where recent archaeological findings from the Athenian Agora's bone well were presented. Finally, different continuing medical educational options in Paediatric Virology were analysed and evaluated. The present review provides an update of the key topics discussed during the workshop.

Clinical definition of respiratory viral infections in young children and potential bronchiolitis misclassification

Viral respiratory infections are often grouped as a single respiratory syndrome named 'viral bronchiolitis', independently of the viral etiology or individual risk factors. Clinical trials and guidelines have used a more stringent definition of viral bronchiolitis, including only the first episode of wheezing in children less than 12 months of age without concomitant respiratory comorbidities. There is increasing evidence suggesting that this definition is not being followed by pediatric care providers, but it is unclear to what extent viral respiratory infections are currently misclassified as viral bronchiolitis using standard definitions. We conducted a retrospective analysis of hospitalized young children (≤3 years) due to viral respiratory infections. Bronchiolitis was defined as the first wheezing episode less than 12 months of age. Demographic variables and comorbidities were obtained by electronic medical record review. The study comprised a total of 513 hospitalizations (n=453). Viral bronchiolitis was diagnosed in 144 admissions (28.1%). Notably, we identified that the majority of children diagnosed with bronchiolitis (63%) were misclassified as they had prior episodes of wheezing. Many children with bronchiolitis misclassification had significant comorbidities, including prematurity (51%), neuromuscular conditions (9.8%), and congenital heart disease (9.8%). Misclassification of bronchiolitis is a common problem that may lead to inappropriate management of viral respiratory infections in young children. A comprehensive approach that takes into consideration viral etiology and individual risk factors may lead to a more accurate clinical assessment of this condition and would potentially prevent bronchiolitis misclassification.

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

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

The Burden and Long-term Respiratory Morbidity Associated with Respiratory Syncytial Virus Infection in Early Childhood

INTRODUCTION

The REGAL (RSV Evidence-a Geographical Archive of the Literature) series provide a comprehensive review of the published evidence in the field of respiratory syncytial virus (RSV) in Western countries over the last 20 years. The objective of this fifth publication was to determine the long-term respiratory morbidity associated with RSV lower respiratory tract infection (RSV LRTI) in early life.

METHODS

A systematic review was undertaken for articles published between January 1, 1995 and December 31, 2015. This was supplemented by inclusion of papers published whilst drafting the manuscript. Studies reporting data on the incidence and long-term wheezing and asthma following RSV LRTI in early life were included. Study quality and strength of evidence (SOE) were graded using recognized criteria.

RESULTS

A total of 2337 studies were identified of which 74 were included. Prospective, epidemiologic studies consistently demonstrated that RSV LRTI is a significant risk factor for on-going respiratory morbidity characterized by transient early wheezing and recurrent wheezing and asthma within the first decade of life and possibly into adolescence and adulthood (high SOE). RSV LRTI was also associated with impaired lung function in these children (high SOE). Respiratory morbidity has been shown to result in reduced quality of life and increased healthcare resource use (moderate SOE). The mechanisms through which RSV contributes to wheezing/asthma development are not fully understood, but appear to relate to the viral injury, preexisting abnormal lung function and/or other factors that predispose to wheezing/asthma, including genetic susceptibility, altered immunology, eosinophilia, and associated risk factors such as exposure to environmental tobacco smoke (high SOE).

CONCLUSION

There is growing evidence that RSV LRTI in early childhood is associated with long-term wheezing and asthma and impaired lung function. Future research should aim to fully elucidate the pathophysiological mechanisms through which RSV causes recurrent wheezing/asthma.

First versus second year respiratory syncytial virus prophylaxis in chronic lung disease (2005-2015)

Children aged <2 years with chronic lung disease (CLD) have a 10-fold higher risk for respiratory syncytial virus-positive hospitalization (RSVH) compared to healthy term infants. Based on the updated position statements, we compared respiratory-related illness hospitalization (RIH) and RSVH risks in CLD children who received palivizumab during the first year (FY) versus second year (SY) of life in the Canadian Registry of Palivizumab (CARESS). Demographic data were collected at enrolment and RIH events recorded monthly from 2005 to 2015. Eight hundred forty-seven FY and 450 SY children with CLD were identified. SY children had a lower gestational age (27 versus 29 weeks) and required more days of respiratory support (64 versus 43), oxygen therapy (108 versus 55), and length of stay (118 versus 73) during the neonatal course compared to FY children; all p < 0.0005. RIH rates were 12.2 (FY) and 18.2 (SY), and RSVH rates were 2.3 (FY) and 3.9 (SY). Cox regression showed similar hazards for both RIH (hazard ratio 0.9, 95% CI 0.6-1.6, p = 0.812) and RSVH (hazard ratio 1.1, 95% CI 0.4-2.9, p = 0.920).

CONCLUSIONS

SY and FY children had similar risks for RIH and RSVH. The findings imply that SY children with CLD are correctly selected for palivizumab based on neonatal illness severity and merit prophylaxis. What is Known: • Children with chronic lung disease have a 10-fold higher risk for RSV-positive hospitalization in comparison to healthy term infants and commonly receive palivizumab prophylaxis as a preventative measure against serious RSV-related lower respiratory tract infections. • The American Academy of Pediatrics [ 2 ] and the Canadian Paediatric Society [ 30 ] have recently modified their recommendations for RSV prophylaxis in children with chronic lung disease, limiting palivizumab to either those <32 weeks gestation or those in the first year of life who are oxygen dependent or require medical therapy for the treatment of their condition. What is New: • Children with chronic lung disease receiving an additional course of palivizumab in their second year of life were determined to be at similar risk for both respiratory illness-related hospitalization and RSV-positive hospitalization as palivizumab-naïve children enrolled in the first year of life in the Canadian Registry for palivizumab (CARESS). • CARESS physicians are correctly identifying high-risk children with chronic lung disease in their second year of life, whom they believe will benefit from an additional year of palivizumab prophylaxis, based on neonatal illness severity.

Functional and genetic predisposition to rhinovirus lower respiratory tract infections in prematurely born infants

Term born infants are predisposed to human rhinovirus (HRV) lower respiratory tract infections (LRTI) by reduced neonatal lung function and genetic susceptibility. Our aim was to investigate whether prematurely born infants were similarly predisposed to HRV LRTIs or any other viral LRTIs. Infants born less than 36 weeks of gestational age were recruited. Prior to neonatal/maternity unit discharge, lung function (functional residual capacity by helium gas dilution and multiple breath washout, lung clearance index and compliance (C_rs), and resistance (R_rs) of the respiratory system) was assessed and DNA samples assessed for eight single nucleotide polymorphisms (SNPs) in seven genes: ADAM33, IL10, MMP16 NFκB1A,SFTPC, VDR, and NOS2A. Infants were prospectively followed until 1 year corrected age. Nasopharyngeal aspirates (NPAs) were sent whenever an infant developed a LRTI and tested for 13 viruses. One hundred and thirty-nine infants were included in the analysis. Infants who developed HRV LRTIs had reduced C_rs (1.6 versus 1.2 mL/cmH₂O/kg, p = 0.044) at 36 weeks postmenstrual age. A SNP in the gene coding for the vitamin D receptor was associated with the development of HRV LRTIs and any viral LRTIs (p = 0.02).

CONCLUSION

Prematurely born infants may have both a functional and genetic predisposition to HRV LRTIs. What is Known: • Term born infants are predisposed to rhinovirus lower respiratory tract (HRV LRTIs) infection by reduced neonatal lung function. • Term born infants requiring hospitalisation due to HRV bronchiolitis were more likely to have single nucleotide polymorphism (SNP) in the IL-10 gene. What is New: • Prematurely born infants who developed a HRV LRTI had lower C _rs before maternity unit discharge. • A SNP in the gene coding for the vitamin D receptor was associated with the development of HRV LRTIs and overall respiratory viral LRTIs in prematurely born infants.

Age-Related Effect of Viral-Induced Wheezing in Severe Prematurity

Premature children are prone to severe viral respiratory infections in early life, but the age at which susceptibility peaks and disappears for each pathogen is unclear. Methods: A retrospective analysis was performed of the age distribution and clinical features of acute viral respiratory infections in full-term and premature children, aged zero to seven years. Results: The study comprised of a total of 630 hospitalizations (n = 580 children). Sixty-seven percent of these hospitalizations occurred in children born full-term (>37 weeks), 12% in preterm (32-37 weeks) and 21% in severely premature children (<32 weeks). The most common viruses identified were rhinovirus (RV; 60%) and respiratory syncytial virus (RSV; 17%). Age-distribution analysis of each virus identified that severely premature children had a higher relative frequency of RV and RSV in their first three years, relative to preterm or full-term children. Additionally, the probability of RV- or RSV-induced wheezing was higher overall in severely premature children less than three years old. Conclusions: Our results indicate that the vulnerability to viral infections in children born severely premature is more specific for RV and RSV and persists during the first three years of age. Further studies are needed to elucidate the age-dependent molecular mechanisms that underlie why premature infants develop RV- and RSV-induced wheezing in early life.

Review of the clinical significance of respiratory virus infections in newborn infants

Respiratory viruses have been recognised as causative agents for a wide spectrum of clinical manifestations and severe respiratory compromise in neonates during birth hospitalisation. Early‐life respiratory virus infections have also been shown to be associated with adverse long‐term consequences.

Conclusion

Preventing virus infections by intensifying hygiene measures and cohorting infected infants should be a major goal for neonatal intensive care units, as well as more common use of virus diagnostics. Active virus surveillance and long‐term follow‐up are needed to ascertain the causality and exact underlying mechanisms for adverse long‐term consequences.

Human metapneumovirus in the preterm neonate: current perspectives

Premature birth (<37 weeks gestation) occurs in ~11% of all births in the US. These infants are at risk of chronic lung disease and respiratory conditions, including bronchopulmonary dysplasia. Respiratory viruses are important causes of acute respiratory illness (ARI) in preterm infants, leading to rehospitalization, increased health care burden, and long-term morbidity. Human metapneumovirus (HMPV) is a paramyxovirus discovered in 2001 that is related to respiratory syncytial virus. Epidemiologic studies show that HMPV is a leading cause of ARI in children and adults worldwide. Prematurity is a major risk factor for severe HMPV disease, requiring hospitalization. Moreover, limited data suggest that HMPV infection during infancy is associated with asthma and recurrent wheezing, which are common long-term pulmonary complication of prematurity. HMPV causes nosocomial outbreaks of ARI in hospitals and long-term care facilities, although there are few studies of the prevalence of HMPV in neonatal intensive care unit populations. HMPV is a common and important virus in premature infants, and caregivers for preterm infants should consider this virus in patients with acute respiratory symptoms.

Current views and advances on Paediatric Virology: An update for paediatric trainees

Paediatric Virology is a bold new scientific field, which combines Paediatrics with Virology, Epidemiology, Molecular Medicine, Evidence-based Medicine, Clinical Governance, Quality Improvement, Pharmacology and Immunology. The Workshop on Paediatric Virology, which took place on Saturday October 10, 2015 in Athens, Greece, provided an overview of recent views and advances on viral infections occurring in neonates and children. It was included in the official programme of the 20th World Congress on Advances in Oncology and the 18th International Symposium on Molecular Medicine, which attracted over 500 delegates from the five continents. During the Workshop, the topics covered included the challenges of vaccine implementation against human papillomaviruses in countries under financial crisis, strategies for eradicating poliomyelitis and its 60th vaccine anniversary, as well as the debate on the association between autism and vaccination against measles, mumps and rubella. Among the non-vaccine related topics, emphasis was given to viral infections in prematurely born infants and their long-term outcomes, new paediatric intensive care management options for bronchiolitis related to respiratory syncytial virus, the clinical implications of hepatitis B virus and cytomegalovirus genotyping, the Ebola virus threat and preparedness in Paediatric Emergency Departments, oral, oropharynx, laryngeal, nasal and ocular viral infections and Merkel cell polyomavirus as a novel emerging virus of infancy and childhood. In this review, we provide selected presentations and reports discussed at the Workshop.

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.

Respiratory consequences of prematurity: evolution of a diagnosis and development of a comprehensive approach

Bronchopulmonary dysplasia (BPD) is the most common respiratory consequence of premature birth and contributes to significant short- and long-term morbidity, mortality and resource utilization. Initially defined as a radiographic, clinical and histopathological entity, the chronic lung disease known as BPD has evolved as obstetrical and neonatal care have improved the survival of lower gestational age infants. Now, definitions based on the need for supplementary oxygen at 28 days and/or 36 weeks provide a useful reference point in the neonatal intensive-care unit (NICU), but are no longer based on histopathological findings, and are neither designed to predict longer term respiratory consequences nor to study the evolution of a multifactorial disease. The aims of this review are to critically examine the evolution of the diagnosis of BPD and the challenges inherent to current classifications. We found that the increasing use of respiratory support strategies that administer ambient air without supplementary oxygen confounds oxygen-based definitions of BPD. Furthermore, lack of reproducible, genetic, biochemical and physiological biomarkers limits the ability to identify an impending BPD for early intervention, quantify disease severity for standardized classification and approaches and reliably predict the long-term outcomes. More comprehensive, multidisciplinary approaches to overcome these challenges involve longitudinal observation of extremely preterm infants, not only those with BPD, using genetic, environmental, physiological and clinical data as well as large databases of patient samples. The Prematurity and Respiratory Outcomes Program (PROP) will provide such a framework to address these challenges through high-resolution characterization of both NICU and post-NICU discharge outcomes.