Descriptive epidemiological features of bronchiolitis in a population-based cohort

Hospitalization of early preterm, late preterm, and term infants during the first year of life by gestational age

OBJECTIVES

The goal of this study was to describe hospitalizations of infants during the first year of life according to week of gestational age (GA). We hypothesized that odds of any hospitalization would generally decrease with increasing GA, with late preterm infants experiencing additional increased risk of specific hospitalizations, such as hyperbilirubinemia.

METHODS

Birth certificates for > 6.6 million infants born in California hospitals between 1993 and 2005 and surviving to discharge were linked to hospital discharge records during the first year of life. Odds of any hospitalization and any hospitalization for specific diagnoses during the first year of life were determined for infants 23 to 44 weeks' GA. Further analysis determined odds of any hospitalization within 14, 30, and 90 days of birth discharge, and observed odds were compared with expected odds obtained through quadratic modeling.

RESULTS

Odds of any hospitalization within the first year of life decreased with advancing GA, but observed odds of any hospitalization exceeded expected odds for 35-, 36-, and 37-week GA infants for all time periods after discharge. Odds of any hospitalization for hyperbilirubinemia were greatest for infants 33 to 38 weeks' GA (peak odds ratio at 36 weeks' GA: 2.86 [95% confidence interval: 2.73-3.00]), and a relative peak in odds of any hospitalization for specific infections was observed among infants 33 to 36 weeks' GA.

CONCLUSIONS

Odds of any hospitalization during the first year of life exceeded expected odds of hospitalization for 35-, 36-, and 37-week GA infants. GAs at risk overlapped with, but were not identical to, GAs identified as late preterm infants.

Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Previous systematic reviews have not shown clear benefit of glucocorticoids for acute viral bronchiolitis, but their use remains considerable. Recent large trials add substantially to current evidence and suggest novel glucocorticoid-including treatment approaches.

OBJECTIVES

To review the efficacy and safety of systemic and inhaled glucocorticoids in children with acute viral bronchiolitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2012, Issue 12), MEDLINE (1950 to January week 2, 2013), EMBASE (1980 to January 2013), LILACS (1982 to January 2013), Scopus® (1823 to January 2013) and IRAN MedEx (1998 to November 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing short-term systemic or inhaled glucocorticoids versus placebo or another intervention in children under 24 months with acute bronchiolitis (first episode with wheezing). Our primary outcomes were: admissions by days 1 and 7 for outpatient studies; and length of stay (LOS) for inpatient studies. Secondary outcomes included clinical severity parameters, healthcare use, pulmonary function, symptoms, quality of life and harms.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on study and participant characteristics, interventions and outcomes. We assessed risk of bias and graded strength of evidence. We meta-analysed inpatient and outpatient results separately using random-effects models. We pre-specified subgroup analyses, including the combined use of bronchodilators used in a protocol.

MAIN RESULTS

We included 17 trials (2596 participants); three had low overall risk of bias. Baseline severity, glucocorticoid schemes, comparators and outcomes were heterogeneous. Glucocorticoids did not significantly reduce outpatient admissions by days 1 and 7 when compared to placebo (pooled risk ratios (RRs) 0.92; 95% confidence interval (CI) 0.78 to 1.08 and 0.86; 95% CI 0.7 to 1.06, respectively). There was no benefit in LOS for inpatients (mean difference -0.18 days; 95% CI -0.39 to 0.04). Unadjusted results from a large factorial low risk of bias RCT found combined high-dose systemic dexamethasone and inhaled epinephrine reduced admissions by day 7 (baseline risk of admission 26%; RR 0.65; 95% CI 0.44 to 0.95; number needed to treat 11; 95% CI 7 to 76), with no differences in short-term adverse effects. No other comparisons showed relevant differences in primary outcomes.

AUTHORS' CONCLUSIONS

Current evidence does not support a clinically relevant effect of systemic or inhaled glucocorticoids on admissions or length of hospitalisation. Combined dexamethasone and epinephrine may reduce outpatient admissions, but results are exploratory and safety data limited. Future research should further assess the efficacy, harms and applicability of combined therapy.

Maternal milk protects infants against bronchiolitis during the first year of life. Results from an Italian cohort of newborns

OBJECTIVE

Bronchiolitis is one of the primary causes of hospitalization in infancy. We evaluated the effect of breastfeeding on the occurrence of hospitalization for bronchiolitis in the first year of life.

METHODS

In a prospective cohort study, 1,814 newborns of =33 weeks of gestational age (wGA) were enrolled in 30 Italian Neonatology Units and followed-up for 1 year to assess hospitalizations for bronchiolitis. Children were grouped as 'never breastfed' and 'ever breastfed'; these latter were further divided into those 'exclusively breastfed' and 'breastfed associated with milk formula'. The risk of hospitalization for bronchiolitis was evaluated with survival analysis, and hazard ratios (HR) with 95% confidence interval [95% CI] were calculated.

RESULTS

Among enrolled newborns 22.9% were 'never breastfed'; in the breastfed group, 65% were 'exclusively breastfed' and 35% were 'breastfed with associated milk formula'. At 12 months of age, the risk of hospitalization for bronchiolitis was significantly higher in the 'never breastfed' group (HR: 1.57; 95% CI: 1.00-2.48). 'Breastfed associated with formula milk' and 'exclusively breastfed' groups were at similar risk of hospitalization for bronchiolitis. This observed protective effect of maternal milk was not explained by the higher prevalence of conditions able to increase the risk of bronchiolitis among 'never breastfed newborns'.

CONCLUSIONS

Breastfeeding, even in association with formula milk, reduces the risk of hospitalization for bronchiolitis during the first year of life. Encouraging breastfeeding might be an effective/inexpensive measure of prevention of lower respiratory tract infections in infancy.

[Epidemiology, clinical features and medical interventions in children hospitalized for bronchiolitis]

OBJECTIVES

To describe the epidemiology, clinical characteristics and treatments prescribed in children with bronchiolitis admitted to our hospital.

MATERIAL AND METHODS

Observational, descriptive and prospective study of children younger than 18 months, admitted to Hospital Virgen de la Arrixaca of Murcia (Spain), with the diagnosis of bronchiolitis, during the season of maximum incidence (December 2008-April 2009).

RESULTS

A total of 235 infants were admitted, of whom 78.7% of them were aged 5 months or less. We found a positive correlation between the number of cigarettes smoked by their mothers during pregnancy and the number of hospitalization and oxygen therapy days. Children whose mothers were smokers at the time of their admission needed a greater number of oxygen therapy days. Also infants who were not breastfed needed oxygen therapy during more days. Just under one quarter (23.8%) of them had underlying diseases, with prematurity being the most frequent and a risk factor for the ongoing of oxygen therapy and hospital stay. The use of diagnostic tests, bronchodilators, corticosteroids and antibiotics was high. The onset of high temperature was associated with an increased use of antibiotics in outside and inside the hospital setting. An abnormal chest X-ray or a raised C-reactive protein was associated with a higher use of antibiotics. Respiratory Syncytial virus (RSV) was the main aetiological agent, followed by Rhinovirus, Bocavirus, Adenovirus and Metapneumovirus

CONCLUSIONS

The majority of hospital admissions due to bronchiolitis took place during the first months of life. Infants whose mothers smoked during pregnancy had a worse clinical outcome. Despite the availability of clinical practice guidelines in our area, the use of diagnostic tests and pharmacological treatment was high.

Respiratory tract illnesses during the first year of life: effect of dog and cat contacts

OBJECTIVES

To investigate the effect of dog and cat contacts on the frequency of respiratory symptoms and infections during the first year of life.

METHODS

In this birth cohort study, 397 children were followed up from pregnancy onward, and the frequency of respiratory symptoms and infections together with information about dog and cat contacts during the first year of life were reported by using weekly diaries and a questionnaire at the age of 1 year. All the children were born in eastern or middle Finland between September 2002 and May 2005.

RESULTS

In multivariate analysis, children having dogs at home were healthier (ie, had fewer respiratory tract symptoms or infections) than children with no dog contacts (adjusted odds ratio, [aOR]: 1.31; 95% confidence interval [CI]: 1.13-1.52). Furthermore, children having dog contacts at home had less frequent otitis (aOR: 0.56; 95% CI: 0.38-0.81) and tended to need fewer courses of antibiotics (aOR: 0.71; 95% CI: 0.52-0.96) than children without such contacts. In univariate analysis, both the weekly amount of contact with dogs and cats and the average yearly amount of contact were associated with decreased respiratory infectious disease morbidity.

CONCLUSIONS

These results suggest that dog contacts may have a protective effect on respiratory tract infections during the first year of life. Our findings support the theory that during the first year of life, animal contacts are important, possibly leading to better resistance to infectious respiratory illnesses during childhood.

Acute bronchiolitis in a paediatric emergency department of Northern Greece. Comparisons between two decades

INTRODUCTION

Acute bronchiolitis is the most common lower respiratory tract infection in infants and toddlers concerning small bronchi or bronchioli. This retrospective study aimed to evaluate the incidence of acute bronchiolitis and the use of β(2)-agonists between two different decades.

MATERIAL AND METHODS

During 1990-1991 and 2001-2002, the files of the 2(nd) Paediatric Emergency Department of Aristotle University of Thessaloniki, AHEPA Hospital were reviewed and cases of acute bronchiolitis were recorded and analysed.

RESULTS

During 1990-1991, 14 538 children were identified with respiratory infections and bronchiolitis was diagnosed in 519/14 538 children (3.56%). Only 34 out of 519 patients received nebulised salbutamol (6.6%) and 221/519 were hospitalized (42.6%). During 2001-2002, 9001 children were found to have respiratory tract infections and acute bronchiolitis was diagnosed in 641/9001 of them (7.12%). In total, 411/641 children (64.1%) received salbutamol and ipratropium, and 89/641 patients (13.88%) were hospitalized. There was a predominance of male sex in both decades (p = 0.509). There was a statistically significant difference (p < 0.001) concerning the use of nebulised salbutamol with nebulised ipratropium between the two decades. Finally, during 2001-2002, the use of bronchodilators with or without corticosteroids was more frequent and it appears to be correlated with the reduced number of admissions to hospital (p < 0.05) compared with 1990-1991.

CONCLUSIONS

There was an increase in the incidence of acute bronchiolitis during the last decade. The admission rate decreased probably due to the use of nebulized salbutamol and ipratropium, but further multicentre comparative trials are required to define the role of bronchodilators in the treatment of acute bronchiolitis.

Systematic literature review assessing tobacco smoke exposure as a risk factor for serious respiratory syncytial virus disease among infants and young children

BACKGROUND

The role of environmental tobacco smoke (ETS) exposure as a risk factor for serious respiratory syncytial virus (RSV) disease among infants and young children has not been clearly established. This systematic review was conducted to explore the association between ETS exposure and serious RSV disease in children younger than 5 years, including infants and young children with elevated risk for serious RSV disease.

METHODS

A systematic review of English-language studies using the PubMed and EMBASE databases (1990-2009) was performed to retrieve studies that evaluated ETS as a potential risk factor for serious RSV illness. Studies assessing risk factors associated with hospitalization, emergency department visit, or physician visit due to RSV (based on laboratory confirmation of RSV or clinical diagnosis of RSV) in children under the age of 5 years were included.

RESULTS

The literature search identified 30 relevant articles, categorized by laboratory confirmation of RSV infection (n = 14), clinical diagnosis of RSV disease (n = 8), and assessment of RSV disease severity (n = 8). Across these three categories of studies, at least 1 type of ETS exposure was associated with statistically significant increases in risk in multivariate or bivariate analysis, as follows: 12 of 14 studies on risk of hospitalization or ED visit for laboratory-confirmed RSV infection; 6 of 8 studies of RSV disease based on clinical diagnosis; and 5 of the 8 studies assessing severity of RSV as shown by hospitalization rates or degree of hypoxia. Also, 7 of the 30 studies focused on populations of premature infants, and the majority (5 studies) found a significant association between ETS exposure and RSV risk in the multivariate or bivariate analyses.

CONCLUSION

We found ample evidence that ETS exposure places infants and young children at increased risk of hospitalization for RSV-attributable lower respiratory tract infection and increases the severity of illness among hospitalized children. Additional evidence is needed regarding the association of ETS exposure and outpatient RSV lower respiratory tract illness. Challenges and potential pitfalls of assessing ETS exposure in children are discussed.

Frequency, duration and predictors of bronchiolitis episodes of care among infants ≥32 weeks gestation in a large integrated healthcare system: a retrospective cohort study

BACKGROUND

Bronchiolitis is common in the first two years of life and is the most frequent cause of hospitalization in this age group. No previous studies have used an episode-of-care analysis to describe the frequency, duration, and predictors of bronchiolitis episodes of care during the first two years.

METHODS

We conducted a retrospective cohort study of 123,264 infants ≥32 weeks gestation born at 6 Northern California Kaiser Permanente hospitals between 1996 and 2002. We used electronic medical records to concatenate hospital, emergency department and outpatient health care encounters for bronchiolitis into discrete episodes of care. We used descriptive statistics to report frequency and duration of bronchiolitis episodes and used logistic regression to assess the effect of gestational age and other clinical and demographic predictors on the outcome of bronchiolitis episodes.

RESULTS

Among all infants, the rate of bronchiolitis episodes was 162 per 1000 children during the first 2 years of life; approximately 40% required >1 day of medical attention with a mean duration of 7.0 ± 5.9 days. Prematurity was associated with increased risk of bronchiolitis episodes and longer duration. Bronchiolitis episodes rates per 1000 infants were 246 for 32-33 weeks gestational age, 204 for 34-36 weeks, and 148-178 for >36 weeks. Male gender, African-American and Hispanic race/ethnicity, and parental history of asthma were associated with an increased risk of having a bronchiolitis episode and/or longer duration.

CONCLUSIONS

Bronchiolitis episodes of care are frequent during the first two years of life and the duration ranges from 1 to 27 days. Prematurity was associated with more frequent and longer duration of bronchiolitis episodes of care, which may reflect illness severity and/or perceived vulnerability.

Clinical predictors of nasal continuous positive airway pressure requirement in acute bronchiolitis

INTRODUCTION

There is growing use of nasal continuous positive airway pressure ventilation (nCPAP) for infants with bronchiolitis, based on clinical assessment of severity. Despite this there have been no studies which identify clinical predictors for the requirement of nCPAP.

OBJECTIVE

To identify clinical factors in infants with acute bronchiolitis in the emergency department (ED), which might predict a requirement for nCPAP following admission.

MATERIALS AND METHODS

Retrospective review of pediatric ED case notes was conducted on bronchiolitis admissions to one dedicated Paediatric ED over a 12-month period. Potential predictors were identified through literature review. Data extraction of predictors was carried out and recorded for each case. Logistic regression was conducted for each variable to identify statistically significant predictors of nCPAP requirement.

RESULTS

Twenty-eight (17%) of the 163 admitted infants received nCPAP. The strongest predictors of nCPAP requirement in were as follows: oxygen requirement within the ED (P < 0.001), lower oxygen saturation (P < 0.001), younger age at presentation (P = 0.002), higher respiratory rate (P = 0.002), higher heart rate (P = 0.003), lower Glasgow Coma Scale score (0.006), and younger gestational age (P = 0.024).

CONCLUSION

We have identified clinical variables that were predictive of nCPAP requirement in infants admitted to our unit with bronchiolitis, oxygen requirement in the ED being the strongest single predictor. This is the first such study in the UK, and we hope it may be a starting point for further work that may provide an evidence base to aid clinicians in predicting the use of nCPAP in infants with bronchiolitis.

Use of palivizumab in primary practice

OBJECTIVE

To describe the implementation of a program for the use of palivizumab in a general pediatrics office and evaluate adherence to the 2009 American Academy of Pediatrics (AAP) guidelines.

METHODS

Pediatricians in a large practice were educated in the diagnosis and management of bronchiolitis, with specific attention to the AAP's palivizumab administration guidelines. During the 2009-2010 and 2010-2011 respiratory syncytial virus seasons, children were systematically identified and enrolled for palivizumab administration. Indication for administration was determined by gestational age, age at the beginning of the respiratory syncytial virus season, pertinent diagnoses, and presence of risk factors.

RESULTS

In the 2009-2010 season, 161 children were enrolled to receive palivizumab, 86 of whom (53%) conformed with AAP guidelines. In contrast, in 2010-2011, a total of 85 children were enrolled to receive palivizumab, and 73 (86%) conformed with the guidelines. As a consequence, the total cost of palivizumab (US $: 511 559 vs 1 500 670) and the cost per child (US $: 6018 vs 9438) were lower in 2010-2011 than in 2009-2010. However, of the children selected within the AAP guidelines, only 29% received the appropriate number of doses, whereas 62% and 9% received fewer or excessive doses, respectively; these findings were similar for the 2 seasons.

CONCLUSIONS

In a primary practice, use of palivizumab outside of the AAP guidelines was frequent and manifested as inadequate indications or inadequate number of doses. The former improved with education and standardization of care (suggesting provider problems), while the latter did not (suggesting system problems). Additional interventions are required.

Household tobacco smoke and admission weight predict severe bronchiolitis in infants independent of deprivation: prospective cohort study

OBJECTIVES

To examine demographic, environmental and clinical factors associated with severe bronchiolitis in infants admitted to hospital and quantify the independent effects of these factors.

DESIGN

Prospective cohort study.

SETTING

Alder Hey Children's Hospital, Liverpool, United Kingdom.

PARTICIPANTS

378 infants admitted to hospital with a diagnosis of bronchiolitis, of whom 299 (79%) were antigen positive to respiratory syncytial virus (RSV).

OUTCOME

Severity of disease during admission, defined as "no need for supplemental oxygen" (reference group), "any need for supplemental oxygen" and "any need for mechanical ventilation".

RESULTS

Univariate analysis found male sex (p = 0.035) and tobacco smoking by a household member (p<0.001) were associated with need for both supplemental oxygen and mechanical ventilation. Premature birth, low gestation, low birth weight, low admission weight and low corrected age on admission were also associated with need for mechanical ventilation (all p≤0.002). Deprivation scores (IMD 2004) were significantly higher in households where a member smoked compared to non-smoking households (p<0.001). The odds of smoking predicted by deprivation were 7 times higher (95%CI (3.59, 14.03)), when comparing the least and most deprived quintiles of the study population. Family history of atopic disease and deprivation score were not associated with severe disease. Multivariate multinomial logistic regression which initially included all covariates, found household tobacco smoking (adjusted OR = 2.45, 95%CI (1.60, 3.74) predicted need for oxygen supplementation. Household tobacco smoking (adjusted OR = 5.49, (2.78, 10.83)) and weight (kg) on admission (adjusted OR = 0.51, (0.40, 0.65)) were both significant predictors in the final model for mechanical ventilation. The same associations and similar size of effects were found when only children with proven RSV infection were included in analysis.

CONCLUSIONS

Low admission weight and householder tobacco smoking increased the risk of severe bronchiolitis in infants admitted to hospital. These effects were independent of a standard deprivation measure. NIHR Study Ref. DHCS/G121/10.

Rhinovirus-associated wheeze during infancy and asthma development

Rhinovirus is commonly associated with bronchiolitis - only second to RSV during the first year life. The prevalence of HRV-bronchiolitis may be very high in predisposed infants. HRV diagnosis is almost exclusively based on PCR, which detects respiratory infections with or without symptoms. Two immunologic factors, interferon responses and atopy, have been associated with susceptibility to HRV-bronchiolitis in multiple studies. The current data supports the hypothesis that susceptibility to HRV-bronchiolitis is likely to be an early manifestation of biased immune responses, which are linked to both decreased viral defence and atopic airway inflammation. Prospective studies have consistently shown that early wheezing associated with HRV infection is closely associated with recurrent wheezing and the development of asthma in children. Collectively, these studies suggest that HRV infection in wheezing children could serve as a clinically useful marker for early identification of asthma prone children. The findings to date provide the rationale for future studies to incorporate rhinovirus illnesses into asthma risk indices.

Parental and household smoking and the increased risk of bronchitis, bronchiolitis and other lower respiratory infections in infancy: systematic review and meta-analysis

BACKGROUND

Passive smoke exposure increases the risk of lower respiratory infection (LRI) in infants, but the extensive literature on this association has not been systematically reviewed for nearly ten years. The aim of this paper is to provide an updated systematic review and meta-analysis of studies of the association between passive smoking and LRI, and with diagnostic subcategories including bronchiolitis, in infants aged two years and under.

METHODS

We searched MEDLINE and EMBASE (to November 2010), reference lists from publications and abstracts from major conference proceedings to identify all relevant publications. Random effect pooled odds ratios (OR) with 95% confidence intervals (CI) were estimated.

RESULTS

We identified 60 studies suitable for inclusion in the meta-analysis. Smoking by either parent or other household members significantly increased the risk of LRI; odds ratios (OR) were 1.22 (95% CI 1.10 to 1.35) for paternal smoking, 1.62 (95% CI 1.38 to 1.89) if both parents smoked, and 1.54 (95% CI 1.40 to 1.69) for any household member smoking. Pre-natal maternal smoking (OR 1.24, 95% CI 1.11 to 1.38) had a weaker effect than post-natal smoking (OR 1.58, 95% CI 1.45 to 1.73). The strongest effect was on bronchiolitis, where the risk of any household smoking was increased by an OR of 2.51 (95% CI 1.96 to 3.21).

CONCLUSIONS

Passive smoking in the family home is a major influence on the risk of LRI in infants, and especially on bronchiolitis. Risk is particularly strong in relation to post-natal maternal smoking. Strategies to prevent passive smoke exposure in young children are an urgent public and child health priority.

Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Previous systematic reviews have not shown clear benefit of glucocorticoids for acute viral bronchiolitis, but their use remains considerable. Recent large trials add substantially to current evidence and suggest novel glucocorticoid-including treatment approaches.

OBJECTIVES

To review the efficacy and safety of systemic and inhaled glucocorticoids in children with acute viral bronchiolitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, issue 4); MEDLINE (1950 to November 2009); EMBASE (1980 to Week 47 2009); LILACS (1982 to November 2009); Scopus® (1823 to November 2009); and IRAN MedEx (1998 to November 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing short-term systemic or inhaled glucocorticoids versus placebo or another intervention in children < 24 months with acute bronchiolitis (first episode with wheezing). Our primary outcomes were: admissions by days 1 and 7 for outpatient studies; and length of stay (LOS) for inpatient studies. Secondary outcomes included clinical severity parameters, healthcare use, pulmonary function, symptoms, quality of life and harms.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on study and participant characteristics, interventions and outcomes. We assessed risk of bias and graded strength of evidence. Inpatient and outpatient results were meta-analysed separately using random-effects models. We pre-specified subgroup analyses, including the combined use of protocolised bronchodilators.

MAIN RESULTS

We included 17 trials (2596 participants); only two had low overall risk of bias. Baseline severity, glucocorticoid schemes, comparators and outcomes were heterogeneous. Glucocorticoids did not significantly reduce outpatient admissions by days 1 and 7 when compared to placebo (pooled risk ratios (RRs) 0.92; 95% CI 0.78 to 1.08; and 0.86; 95% CI 0.7 to 1.06, respectively). There was no benefit in LOS for inpatients (mean difference -0.18 days; 95% CI -0.39 to 0.04). Unadjusted results from a large factorial low risk of bias RCT found combined high-dose systemic dexamethasone and inhaled epinephrine reduced admissions by day 7 (baseline risk of admission 26%; RR 0.65, 95% CI 0.44 to 0.95; number needed to treat 11, 95% CI 7 to 76), with no differences in short-term adverse effects. No other comparisons showed relevant differences in primary outcomes.

AUTHORS' CONCLUSIONS

Current evidence does not support a clinically relevant effect of systemic or inhaled glucocorticoids on admissions or length of hospitalization. Combined dexamethasone and epinephrine may reduce outpatient admissions, but results are exploratory and safety data limited. Future research should further assess the efficacy, harms and applicability of combined therapy.

Effectiveness of chest physiotherapy in infants hospitalized with acute bronchiolitis: a multicenter, randomized, controlled trial

BACKGROUND

Acute bronchiolitis treatment in children and infants is largely supportive, but chest physiotherapy is routinely performed in some countries. In France, national guidelines recommend a specific type of physiotherapy combining the increased exhalation technique (IET) and assisted cough (AC). Our objective was to evaluate the efficacy of chest physiotherapy (IET + AC) in previously healthy infants hospitalized for a first episode of acute bronchiolitis.

METHODS AND FINDINGS

We conducted a multicenter, randomized, outcome assessor-blind and parent-blind trial in seven French pediatric departments. We recruited 496 infants hospitalized for first-episode acute bronchiolitis between October 2004 and January 2008. Patients were randomly allocated to receive from physiotherapists three times a day, either IET + AC (intervention group, n=246) or nasal suction (NS, control group, n=250). Only physiotherapists were aware of the allocation group of the infant. The primary outcome was time to recovery, defined as 8 hours without oxygen supplementation associated with minimal or no chest recession, and ingesting more than two-thirds of daily food requirements. Secondary outcomes were intensive care unit admissions, artificial ventilation, antibiotic treatment, description of side effects during procedures, and parental perception of comfort. Statistical analysis was performed on an intent-to-treat basis. Median time to recovery was 2.31 days, (95% confidence interval [CI] 1.97-2.73) for the control group and 2.02 days (95% CI 1.96-2.34) for the intervention group, indicating no significant effect of physiotherapy (hazard ratio [HR]=1.09, 95% CI 0.91-1.31, p=0.33). No treatment by age interaction was found (p=0.97). Frequency of vomiting and transient respiratory destabilization was higher in the IET + AC group during the procedure (relative risk [RR]=10.2, 95% CI 1.3-78.8, p=0.005 and RR=5.4, 95% CI 1.6-18.4, p=0.002, respectively). No difference between groups in bradycardia with or without desaturation (RR=1.0, 95% CI 0.2-5.0, p=1.00 and RR=3.6, 95% CI 0.7-16.9, p=0.10, respectively) was found during the procedure. Parents reported that the procedure was more arduous in the group treated with IET (mean difference=0.88, 95% CI 0.33-1.44, p=0.002), whereas there was no difference regarding the assessment of the child's comfort between both groups (mean difference=-0.07, 95% CI -0.53 to 0.38, p=0.40). No evidence of differences between groups in intensive care admission (RR=0.7, 95% CI 0.3-1.8, p=0.62), ventilatory support (RR=2.5, 95% CI 0.5-13.0, p=0.29), and antibiotic treatment (RR=1.0, 95% CI 0.7-1.3, p=1.00) was observed.

CONCLUSIONS

IET + AC had no significant effect on time to recovery in this group of hospitalized infants with bronchiolitis. Additional studies are required to explore the effect of chest physiotherapy on ambulatory populations and for infants without a history of atopy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00125450.

Lower interleukin-8 levels in airway aspirates from breastfed infants with acute bronchiolitis

Breastfeeding during the first 12 months of life confers demonstrable immunologic benefit against infective pathogens, including those of the respiratory tract. However, the mechanism by which the ingestion of human milk modifies immunologic defense against such pathogens remains elusive. Bronchiolitis, caused predominantly by respiratory syncytial virus, is the most common clinical presentation of severe upper respiratory illness requiring hospitalization in infants and remains one of the developed world's leading causes of infant mortality and morbidity over both the short and long term. The mechanism by which an early, severe case of bronchiolitis can result in the development of recurrent childhood wheeze or asthma is unclear; however, mucosal inflammation and pulmonary neutrophilia are believed to play a significant role. The aim of this study was to examine the immune response of breastfed infants hospitalized with severe bronchiolitis, compared with formula-fed controls. Nasopharyngeal aspirates (NPA) were collected from 18 infants (aged <or=12 months), seven breastfed and 11 formula fed and assayed by enzyme immunoassays for chemokines interleukin (IL)-8 and monocyte chemotactic protein (MCP)-1. NPA cellular component was quantified by light microscopy. Breastfed infants had lower levels of the chemokine IL-8 in their nasal airways with a concurrent decrease in cellular infiltrate (p <or= 0.04). NPA cell number correlated with lactoferrin concentration (p = 0.02) but not with myeloperoxidase, suggesting the predominance of mature, secondary granule laden neutrophils. These findings indicate a potential mechanism of protective immune regulation during bronchiolitis in the breastfed infant.

Acute viral bronchiolitis in children- a very common condition with few therapeutic options

Acute viral bronchiolitis remains a cause of substantial morbidity and health care costs in young infants. It is the most common lower respiratory tract condition and most common reason for admission to hospital in infants. Many respiratory viruses have been associated with acute viral bronchiolitis although respiratory syncytial virus (RSV) remains the most frequently identified virus. Most infants have a mild self limiting illness while others have more severe illness and require hospital admission and some will need ventilatory support. Differences in innate immune function in response to the respiratory viral insult as well as differences in the geometry of the airways may explain some of the variability in clinical pattern. Young age and history of prematurity remain the most important risk factors although male gender, indigenous status, exposure to tobacco smoke, poor socioeconomic factors and associated co-morbidities such as chronic lung disease and congenital heart disease increase the risks of more severe illness. Supportive therapy remains the major treatment option as no specific treatments to date have been shown to provide clinically important benefits except for inhaled hypertonic saline. Prophylaxis of high risk infants with palivizumab should be considered although the cost effectiveness is still unclear. Many questions remain regarding optimal management approaches for infants requiring hospitalisation with bronchiolitis including use of nasogastric feeding, the optimal role of supplemental oxygen, optimal use of hypertonic saline and the role of combinations of therapies, the use of heliox or modern physiotherapy approaches.

Lower respiratory tract infections

Acute lower respiratory infections (ALRI) are the major cause of morbidity and mortality in young children worldwide. ALRIs are important indicators of the health disparities that persist between Indigenous and non-Indigenous children in developed countries. Bronchiolitis and pneumonia account for the majority of the ALRI burden. The epidemiology, diagnosis, and management of these diseases in Indigenous children are discussed. In comparison with non-Indigenous children in developing countries they have higher rates of disease, more complications, and their management is influenced by several unique factors including the epidemiology of disease and, in some remote regions, constraints on hospital referral and access to highly trained staff. The prevention of repeat infections and the early detection and management of chronic lung disease is critical to the long-term respiratory and overall health of these children.

Burden of infant bronchiolitis: data from a hospital network

In France, surveillance of bronchiolitis is based on a pilot network of hospital emergency departments. The study was a 1-year observational study (2007-2008) carried out in a central region of metropolitan France. The hospitalization rate for bronchiolitis was 17.7/1000 children aged <1 year and the estimated prevalence of bronchiolitis ranged from 17.7% to 34.4% in children aged <1 year. Such a network constitutes a valuable tool to estimate the dynamic and the burden of infant bronchiolitis.

Risk factors and viruses associated with hospitalization due to lower respiratory tract infections in Canadian Inuit children : a case-control study

OBJECTIVES

To examine risk factors for lower respiratory tract infections (LRTI) hospital admission in the Canadian Arctic.

METHODS

This was a case-control study during a 14-month period among children less than 2 years of age. Cases were admitted to the Baffin Regional Hospital in Iqaluit, Nunavut with LRTI. Controls were age matched and came from Iqaluit and 2 communities. Odds ratios (ORs) of hospital admission for LRTI were estimated through multivariate conditional logistic regression modeling for following risk factors: smoking in pregnancy, Inuit race, prematurity, adoption status, breast-feeding, overcrowding, and residing outside of Iqaluit. Viruses in nasophayngeal aspirates were sought at the time of each hospital admission.

RESULTS

There were 101 age-matched cases and controls. The following risk factors were significantly associated with an increased risk of admission for LRTI (adjusted OR): smoking in pregnancy (OR = 4.0; 95% CI: 1.1-14.6), residence outside of Iqaluit (OR = 2.7; 95% CI: 1.0 -7.2), full Inuit race (OR = 3.8; 95% CI: 1.1-12.8), and overcrowding (OR = 2.5, 95% CI: 1.1- 6.1). Non-breast-fed children had a 3.6-fold risk of being admitted for LRTI (95% CI: 1.2-11.5) and non-breast-fed adopted children had a 4.4-fold increased risk (95% CI: 1.1-17.6) when compared with breast-fed, nonadopted children. Prematurity was not associated with an increased risk of admission. Viruses were identified in 88 (72.7%) of admissions, with respiratory syncytial virus being identified in the majority of admissions, 62 (51.2%). Multiple viruses were isolated in 19 (15.7%) admissions.

CONCLUSIONS

Smoking during pregnancy, place of residence, Inuit race, lack of breast-feeding, and overcrowding were all independently associated with increased risk of hospital admission for LRTI among Inuit children less than 2 years of age. Future research on the role of adoption and genetics on the health of Inuit children are required.