The link between bronchiolitis and asthma

Clinical Characteristics of Pediatric Parainfluenza Virus Infections: A Comparative Analysis of Parainfluenza Virus Serotypes 1-4 From April 2021 to October 2023 in Hokkaido, Japan

BACKGROUND

Parainfluenza virus (PIV) is widely known as a causative virus of acute respiratory tract infections in children, and 4 serotypes (PIV-1-PIV-4) have been identified. The purpose of the present study was to clarify the clinical characteristics of the PIV serotypes in pediatric PIV infections in Japan.

METHODS

Between April 2021 and October 2023, 8821 children aged <16 years who presented with respiratory symptoms underwent multiplex polymerase chain reaction analyses at the Department of Pediatrics, NTT Medical Center Sapporo. All 1490 cases in which PIV was detected were analyzed for their clinical characteristics by PIV serotypes.

RESULTS

Of the 1490 cases, 608 were positive for a single PIV serotype: 91 (13.5%) for PIV-1, 54 (4.8%) for PIV-2, 361 (62.1%) for PIV-3 and 102 (19.6%) for PIV-4. The median ages were 3.5 years for PIV-1, 5.4 years for PIV-2, 1.9 years for PIV-3 and 2.2 years for PIV-4, with a significantly older age for PIV-2. Compared with the other serotypes, croup was significantly more common in PIV-1 and lower respiratory tract infection was significantly more common in PIV-4. Of the 608 cases with a single PIV serotype, 114 were hospitalized. The proportion of hospitalized patients was higher for PIV-4 than for the other PIV serotypes, but the difference was not significant.

CONCLUSIONS

Lower respiratory tract infection was more frequent in PIV-4 than in the other PIV serotypes, and PIV-4 infection may increase the risk of hospitalization.

The association of prehospital systemic corticosteroids with emergency department and in-hospital outcomes for patients with asthma exacerbations

BACKGROUND

Timely administration of systemic corticosteroids is a cornerstone of asthma exacerbation treatment, yet little is known regarding potential benefits of prehospital administration by emergency medical services (EMS) clinicians. We examined factors associated with prehospital corticosteroid administration with hospitalization and hospital length of stay (LOS).

METHODS

We performed a retrospective study of EMS encounters for patients 2-50 years of age with suspected asthma exacerbation from a national data set. We evaluated factors associated with systemic corticosteroid administration using generalized estimating equations. We performed propensity matching based on service level, age, encounter duration, vital signs, and treatments to evaluate the association of prehospital corticosteroid administration with hospitalization and LOS using weighted logistic regression. We evaluated the association of prehospital corticosteroid administration with admission using Bayesian models.

RESULTS

Of 15,834 encounters, 4731 (29.9%) received prehospital systemic corticosteroids. Administration of corticosteroids was associated with older age; sex; urbanicity; advanced life support provider; vital sign instability; increasing doses of albuterol; and provision of ipratropium bromide, magnesium, epinephrine, and supplementary oxygen. Within the matched sample, prehospital corticosteroids were not associated with hospitalization (odds ratio [OR] 0.86, 95% confidence interval [CI] 0.73-1.01) or LOS (multiplier 0.76, 95% CI 0.56-1.05). Administration of corticosteroids was associated with lower odds of admission and shorter LOS in longer EMS encounters (>34 min), lower admission odds in patients with documented wheezing, and shorter LOS among patients treated with albuterol. In a Bayesian model with noninformative priors, the OR for admission among encounters given corticosteroids was 0.86 (95% credible interval 0.77-0.96).

CONCLUSIONS

Prehospital systemic corticosteroid administration was not associated with hospitalization or LOS in the overall cohort of asthma patients treated by EMS, though they had a lower probability of admission within Bayesian models. Improved outcomes were noted among subgroups of longer EMS encounters, documented wheezing, and receipt of albuterol.

Bronchiolitis hospital admission in infancy is associated with later preschool ventilation inhomogeneity

BACKGROUND

Rhinovirus (RV) positive bronchiolitis episodes in infancy confer a higher risk to develop asthma in later childhood with associated lung function impairments. We aimed to investigate the association between the type of virus causing a bronchiolitis hospitalization episode and lung ventilation inhomogeneities at preschool age.

METHODS

Infants hospitalized with a clinical diagnosis of moderate (ward admission) or severe (pediatric intensive care ward admission) bronchiolitis were prospectively followed-up at preschool age to assess nitrogen (N2 ) multiple breath washout (MBW). Lung clearance index (LCI), functional residual capacity (FRC), and concentration normalized phase III slope analysis (SnIII ) indices were reported from ≥2 technically acceptable trials. Differences between groups were calculated using logistic and linear regression and adjusted for confounders (sex, age at bronchiolitis admission, height at visit, maternal asthma, and doctor-diagnosed asthma, including interaction terms between the latter three). An interaction term was included in a regression model to test for an interaction between RV bronchiolitis severity and MBW parameters at preschool age.

RESULTS

One hundred and thirty-nine subjects attended preschool follow-up, of which 84 out of 103 (82%) performing MBW had technically acceptable data. Children with a history of RV positive bronchiolitis (n = 39) had increased LCI (adjusted β-coefficient [aβ] = 0.33, 95% confidence interval [CI] 0.02-0.65, p = 0.040) and conductive airways ventilation inhomogeneity [Scond ] (aβ = 0.016, CI 0.004-0.028, p = 0.011) when compared with those with a RV negative bronchiolitis history (n = 45). In addition, we found a statistical interaction between RV bronchiolitis and bronchiolitis severity strengthening the association with LCI (aβ = 0.93, CI 0.20-1.58, p = 0.006).

CONCLUSION

Children with a history of hospital admission for RV positive bronchiolitis in infancy might be at a higher risk of lung ventilation inhomogeneities at preschool age, arising from the peripheral conducting airways.

Bronchiolitis, Regardless of Its Etiology and Severity, Is Associated With Increased Risk of Asthma: A Population-Based Study

An association exists between severe respiratory syncytial virus (RSV)-bronchiolitis and a subsequent increased risk of recurrent wheezing (RW) and asthma. However, a causal relationship remains unproven. Using a retrospective population-based cohort study (339 814 children), bronchiolitis during the first 2 years of life (regardless of etiology and severity) was associated with at least a 3-fold increased risk of RW/asthma at 2-4 years and an increased prevalence of asthma at ≥5 years of age. The risk was similar in children with mild bronchiolitis as in those with hospitalized RSV-bronchiolitis and was higher in children with hospitalized non-RSV-bronchiolitis. The rate of RW/asthma was higher when bronchiolitis occurred after the first 6 months of life. Our results seem to support the hypothesis of a shared predisposition to bronchiolitis (irrespective of etiology) and RW/asthma. However, 60% of hospitalized bronchiolitis cases in our setting are due to RSV, which should be paramount in decision-making on imminent RSV prevention strategies.

Bronchodilator-responsive bronchiolar obstruction in term neonates: a case series

BACKGROUND

Bronchiolar obstruction, which causes airway obstruction in hyperresponsive airways, often results from the contraction of the airway's smooth muscles, increased viscid mucous secretions, and mucosal oedema consequent upon a reduced cyclic 3,5-adenosine monophosphate (c-AMP). These processes respond to bronchodilators. The six cases presented to us, in Edward Francis Small Teaching Hospital (EFSTH), Banjul, The Gambia, in the newborn period with clinical features suggesting obstruction with airway reactivity with response to bronchodilator treatment are presented here. Our capacity-limited literature search did not show any such report in neonates. This report highlights the need for this condition to be sought in neonates, medically managed in resource-poor countries without resorting to high-cost equipment use, and for its possible future classification.

CASE PRESENTATION

We report six cases of Gambian neonates consisting of four males and two females ages 2-27 days who presented to us with histories of fast breathing of a few hours duration and expiratory respiratory distress. All were term babies with rhonchi and demonstrable prolonged expiration with terminal effort. They all had a diagnosis of hyperreactive airway disease with bronchiolar obstruction. Five cases were first-time wheezers, while one was a recurrence. All were eventually treated with bronchodilators and steroids with good results. The median duration for resolution of most symptoms with treatment was two days, with a range of 1-5 days.

CONCLUSION

Clinically determined bronchiolar obstructions in term neonates can be relieved with bronchodilators and steroids, and this treatment modality, if employed where the pathological process can be established, can reduce the demand on scarce resources in resource-poor countries.

Acute Bronchitis and Bronchiolitis Infection in Children with Asthma and Allergic Rhinitis: A Retrospective Cohort Study Based on 5,027,486 Children in Taiwan

This study evaluated the risks of childhood acute bronchitis and bronchiolitis (CABs) for children with asthma or allergic rhinitis (AR). Using insurance claims data of Taiwan, we identified, from children of ≤12 years old in 2000-2016, cohorts with and without asthma (N = 192,126, each) and cohorts with and without AR (N = 1,062,903, each) matched by sex and age. By the end of 2016, the asthma cohort had the highest bronchitis incidence, AR and non-asthma cohorts followed, and the lowest in the non-AR cohort (525.1, 322.4, 236.0 and 169.9 per 1000 person-years, respectively). The Cox method estimated adjusted hazard ratios (aHRs) of bronchitis were 1.82 (95% confidence interval (CI), 1.80-1.83) for the asthma cohort and 1.68 (95% CI, 1.68-1.69) for the AR cohort, relative to the respective comparisons. The bronchiolitis incidence rates for these cohorts were 42.7, 29.5, 28.5 and 20.1 per 1000 person-years, respectively. The aHRs of bronchiolitis were 1.50 (95% CI, 1.48-1.52) for the asthma cohort and 1.46 (95% CI, 1.45-1.47) for the AR cohort relative to their comparisons. The CABs incidence rates decreased substantially with increasing age, but were relatively similar for boys and girls. In conclusion, children with asthma are more likely to develop CABs than are children with AR.

Long-Term Pulmonary Outcomes in Children Mechanically Ventilated for Severe Bronchiolitis

OBJECTIVES

Bronchiolitis is a common indication for mechanical ventilation in the PICU. Both bronchiolitis and invasive mechanical ventilation may cause adverse long-term pulmonary outcomes. This study investigates children with a history of invasive mechanical ventilation for bronchiolitis, addressing: 1) the extent, 2) potential explanatory factors, and 3) possible impact on daily life activities of adverse long-term pulmonary outcomes.

DESIGN

Single-center cohort study.

SETTING

Outpatient PICU follow-up clinic.

PATIENTS

Children 6-12 years old with a history of invasive mechanical ventilation for bronchiolitis (age &lt; 2 yr).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Long-term pulmonary outcomes were assessed by a standardized questionnaire and by spirometry. Nineteen out of 74 included children (26%) had adverse long-term pulmonary outcomes, of whom the majority had asthma (14/74, 19%). By logistic regression analysis, we assessed whether background characteristics and PICU-related variables were associated with long-term pulmonary outcomes. In general, we failed to identify any explanatory factors associated with adverse long-term pulmonary outcomes. Nonetheless, atopic disease in family and longer duration of invasive mechanical ventilation (days) were associated with greater odds of having asthma at follow-up (odds ratio, 6.4 [95% CI, 1.2-36.0] and 1.3 [95% CI, 1.0-1.7], respectively). Adverse pulmonary outcome at follow-up was associated with more frequent use of pulmonary medication after PICU discharge. In comparison with those without adverse pulmonary outcomes, we did not identify any difference in frequency of sports performance or school absenteeism.

CONCLUSIONS

In this single-center cohort, one-quarter of the children attending follow-up with a history of invasive mechanical ventilation for bronchiolitis had adverse, mostly previously undetected, long-term pulmonary outcomes at 6-12 years. Atopic disease in family and longer duration of invasive mechanical ventilation were associated with presence of asthma. The presence of adverse pulmonary outcomes was associated with more frequent use of pulmonary medication after PICU discharge.

Racial and ethnic disparities in bronchiolitis management in freestanding children's hospitals

OBJECTIVE

Variation in bronchiolitis management by race and ethnicity within emergency departments (EDs) has been described in single-center and prospective studies, but large-scale assessments across EDs and inpatient settings are lacking. Our objective is to describe the association between race and ethnicity and bronchiolitis management across 37 U.S. freestanding children's hospitals from 2015 to 2018.

METHODS

Using the Pediatric Health Information System, we analyzed ED and inpatient visits from November 2015 to November 2018 of children with bronchiolitis 3 to 24 months old. Rates of use for specific diagnostic tests and therapeutic measures were compared across the following race/ethnicity categories: 1) non-Hispanic White (NHW), 2) non-Hispanic Black (NHB), 3) Hispanic, and 4) other. The subanalyses of ED patients only and children < 1 year old were performed. Mixed-effect logistic regression was performed to compare the adjusted odds of receiving specific test/treatment using NHW children as the reference group.

RESULTS

A total of 134,487 patients met inclusion criteria (59% male, 28% NHB, 26% Hispanic). Adjusted analysis showed that NHB children had higher odds of receiving medication associated with asthma (odds ratio [OR] = 1.27, 95% confidence interval [CI] = 1.22 to 1.32) and lower odds of receiving diagnostic tests (blood cultures, complete blood counts, viral testing, chest x-rays; OR = 0.78, 95% CI = 0.75 to 0.81) and antibiotics (OR = 0.58, 95% CI = 0.52 to 0.64) than NHW children. Hispanic children had lower odds of receiving diagnostic testing (OR = 0.94, 95% CI = 0.90 to 0.98), asthma-associated medication (OR = 0.92, 95% CI = 0.88 to 0.96), and antibiotics (OR = 0.74, 95% CI = 0.66 to 0.82) compared to NHW children.

CONCLUSION

NHB children more often receive corticosteroid and bronchodilator therapies; NHW children more often receive antibiotics and chest radiography. Given that current guidelines generally recommend supportive care with limited diagnostic testing and medical intervention, these findings among NHB and NHW children represent differing patterns of overtreatment. The underlying causes of these patterns require further investigation.

Rhinovirus spread in children during the COVID-19 pandemic despite social restrictions-A nationwide register study in Finland

Social restrictions during the coronavirus disease 2019 pandemic strongly affected the epidemiology of influenza and respiratory syncytial virus (RSV). As rhinovirus seemed to spread despite the restrictions, we aimed to analyze rhinovirus epidemiology in children during the pandemic. This register‐based study used data from the Finnish Infectious Disease Register. Nationwide rhinovirus findings from July 2015 to March 2021 were included and stratified by age (0–4, 5–9, and 10–14). Cumulative 14‐day incidence per 100000 children was calculated. Four thousand five hundred and seventy six positive rhinovirus findings were included, of which 3788 (82.8%) were among children aged 0–4. The highest recorded incidence was 36.2 among children aged 0–4 in October 2017. The highest recorded incidence during the pandemic period was 13.6 in November 2020. The impact of the restrictions was mostly seen among children aged 0–4 years of age in weeks 14–22 in 2020. The incidence has since remained near reference levels in all age groups. Strict restrictions temporarily interrupted the circulation of rhinovirus in spring 2020. Rhinovirus incidence returned to normal levels soon after the harsh restrictions were lifted. These looser social restrictions prevented RSV and influenza seasons but failed to prevent the spread of rhinovirus.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Interleukin-10 gene polymorphism rs1800896 is associated with post-bronchiolitis asthma at 11-13 years of age

AIM

Interleukin-10 (IL-10) is an anti-inflammatory cytokine that is involved with bronchiolitis and asthma. We evaluated associations between four IL-10 polymorphisms, namely rs1800871, rs1800872, rs1800890 and rs1800896, and post-bronchiolitis asthma in young adolescents.

METHODS

The cohort consisted of 125 children hospitalised for bronchiolitis at Tampere University Hospital, Finland, in 2000-2004, at less than six months of age. At 11-13 years, asthma diagnoses and asthma-presumptive symptoms, allergic rhinitis and use of inhaled corticosteroids (ICS) were registered. Data on the four polymorphisms and their genotypes, haplotypes and allele frequencies were analysed in relation to asthma, allergic rhinitis and asthma medication.

RESULTS

The variant IL-10 rs1800896 genotype was associated with less persistent asthma at five to seven and 11-13 years of age (4.3 versus 15.2%, p = 0.04) than the wild genotype and less ICS use during the previous 12 months (5.4 versus 18.2%, p = 0.03), as was the variant allele G. Allele A was associated with more persistent asthma and ICS use. The significant differences between the variant and wild genotypes were lost in adjusted logistic regression, but the direction of the association remained.

CONCLUSION

IL-10 rs1800896 gene polymorphism was associated with post-bronchiolitis asthma at 11-13 years of age in children hospitalised for bronchiolitis at less than six months of age.

Polymorphisms in the promoter region of IL10 gene are associated with virus etiology of infant bronchiolitis

BACKGROUND

Bronchiolitis is the most common infection leading to hospitalization in infancy. Interleukin-10 (IL-10) is an anti-inflammatory cytokine, and in our previous study, IL10 gene rs1800896 (- 1082A/G) polymorphism was associated with viral etiology of infant bronchiolitis. The objective of this study was to evaluate the associations between IL10 single nucleotide polymorphisms (SNPs) at rs1800890 (- 3575A/T), rs1800871 (- 819C/T) or rs1800872 (- 592C/A) either alone or combined with the SNP at rs1800896 (- 1082G/A), and the etiology and severity of infant bronchiolitis.

METHODS

Data on four IL10 SNPs were available from 135 full-term infants, hospitalized for bronchiolitis at age less than 6 months, and from 378 to 400 controls. Viral etiology was studied, and oxygen support, feeding support and the length of stay in hospital were recorded during bronchiolitis hospitalization.

RESULTS

Infants with rhinovirus bronchiolitis had the IL10 rs1800890 variant AT or TT genotype less often (18.2%) than controls (63.3%, P = 0.03), and likewise, had the IL10 rs1800896 variant AG or GG genotype less often (27.3%) than controls (65.5%, P = 0.009). Twenty-eight infants with bronchiolitis had the variant-variant G_rs1800896T_rs1800890 haplotype, and none of them had rhinovirus infection. The IL10 rs1800871 or rs1800872 genotypes showed no associations with viruses. No association was found between any genotypes and bronchiolitis severity measures.

CONCLUSION

IL10 rs1800890 and rs1800896 polymorphisms differed between infants with rhinovirus bronchiolitis and controls, but not between infants with respiratory syncytial virus bronchiolitis and controls.

Multicenter Study of Albuterol Use Among Infants Hospitalized with Bronchiolitis

INTRODUCTION

Although bronchiolitis is a common reason for infant hospitalization, significant heterogeneity persists in its management. The American Academy of Pediatrics currently recommends that inhaled albuterol not be used in routine care of children with bronchiolitis. Our objective was to identify factors associated with pre-admission (e.g., emergency department or primary care) use of albuterol among infants hospitalized for bronchiolitis.

METHODS

We analyzed data from a 17-center observational study of 1,016 infants (age <1 year) hospitalized with bronchiolitis between 2011-2014. Pre-admission albuterol use was ascertained by chart review, and data were available for 1,008 (99%) infants. We used multivariable logistic regression to identify infant characteristics independently associated with pre-admission albuterol use.

RESULTS

Half of the infants (n=508) received at least one albuterol treatment before admission. Across the 17 hospitals, pre-admission albuterol use ranged from 23-84%. In adjusted analysis, independent predictors of albuterol use were the following: age ≥2 months (age 2.0-5.9 months [odds ratio (OR) 2.09, 95% confidence interval (CI) {1.45-3.01}] and age 6.0-11.9 months [OR 2.89, 95% CI {1.99-4.19}]); prior use of a bronchodilator (OR 1.89, 95% CI [1.24-2.90]); and presence of wheezing documented in pre-admission chart (OR 3.94, 95% CI [2.61-5.93]). By contrast, albuterol use was less likely among those with ≥7 days since the start of breathing problem (OR 0.66, 95% CI [0.44-1.00]) and parent-reported fever (OR 0.75, 95% CI [0.58-0.96]).

CONCLUSION

Variation in pre-admission albuterol use suggests that local practice had a strong influence on use, but that patient characteristics also influenced the decision. While we agree with current guidelines in recommending against albuterol for all infants with bronchiolitis, our understanding of possible subgroups of responders may improve through investigation of infants with the identified characteristics.

Low age, low birthweight and congenital heart disease are risk factors for intensive care in infants with bronchiolitis

AIM

This study evaluated the incidence and risk factors for intensive care and respiratory support in infant bronchiolitis.

METHODS

This retrospective descriptive case-control study focused on 105 patients treated in the paediatric intensive care unit (PICU) and 210 controls treated in the emergency department or on the paediatric ward in Tampere University Hospital in Finland between 2000 and 2015. Statistically significant risk factors in nonadjusted analyses were included in the adjusted logistic regression.

RESULTS

The average age-specific annual incidence of bronchiolitis requiring PICU admission under the age of 12 months was 1.5/1000/year (range 0.18-2.59). Independently, significant risk factors for PICU admission were as follows: being less than two months old with an adjusted odds ratio (aOR) of 11.5, birthweight of <2000 g (aOR of 15.9), congenital heart disease (CHD) (aOR of 15.9), apnoea (aOR of 7.2) and the absence of wheezing (aOR of 2.2). Significant risk factors for needing respiratory support were a birthweight of <2000 g, an age of less than two months and CHD.

CONCLUSION

Less than 0.1% of infants under the age of 12 months were admitted to the PICU for bronchiolitis. Low age, low birthweight or prematurity and CHD were independently significant risk factors for both intensive care and respiratory support.

IL-10 gene polymorphism is associated with preschool atopy and early-life recurrent wheezing after bronchiolitis in infancy

BACKGROUND

Variations in the genes that regulate innate immunity responses may be associated with susceptibility to asthma or atopy after early-life bronchiolitis. The aim of this study was to evaluate the association between four different polymorphisms of the IL-10 gene at rs1800871, rs1800872, rs1800890, and rs1800896, either alone or in combination, and post-bronchiolitis asthma or allergies at 5-7 years of age.

METHODS

Data on single nucleotide polymorphisms (SNP) of IL-10 rs1800896 (-1082G/A), rs1800871 (-819C/T), rs1800872 (-592C/A), and IL-10 rs1800890 (-3575T/A) were available for 135 children. Polymorphisms and their associations with asthma and allergies were studied in 135 preschool-aged children who had been hospitalized for bronchiolitis at age 0-6 months. Their parents were interviewed to record the children's history with asthma and allergies from infancy to the present.

RESULTS

At 6.4 years (mean), asthma was present in 17 children (12.6%), while recurrent wheezing during the first 7 years of life was present in 39 (28.9%) children. Fifty-three (39.3%) study participants had current atopy (atopic eczema or allergic rhinitis). Eight (72%) of 11 children with the IL-10 rs1800896, IL-10 rs1800871, and IL-10 rs1800872 combination AA + CT + CA had current atopy (P = 0.02 vs. 38% in other genotype combinations). Twenty-three (56%) children with the IL-10 rs1800871C/T or IL-10 rs1800872C/A genotype had present atopy versus 34 (38%) with other IL-10 genotypes (P = 0.03). Between 2 years and 3 years of age, 27% of ATA haplotype carriers had asthma versus 13.7% of other haplotype carriers (P = 0.02).

CONCLUSIONS

IL-10 polymorphisms at rs1800871, rs1800872, rs1800890, and rs1800896 seem to be associated with elevated allergies and/or recurrent wheezing risk in later childhood, after early-life bronchiolitis. Pediatr Pulmonol. 2017;52:14-20. © 2016 Wiley Periodicals, Inc.

Antimicrobial therapy in childhood asthma and wheezing

There is an increasing number of viral and bacterial pathogens suspected of contributing to asthma pathogenesis in childhood, making it more difficult for the practitioner to make specific therapy decisions. This review discusses the role of viruses, e.g. respiratory syncytial virus, human metapneumovirus, influenza viruses and rhinoviruses, as well as the role of the atypical bacteria Chlamydophila pneumoniae and Mycoplasma pneumoniae, as contributors to childhood asthma. Diagnosis, prevention, and therapy are discussed, including a summary of drugs, i.e. macrolide antibacterials, antivirals, and vaccine regimens already available, or at least in clinical trials. For the practitioner dealing with patients every day, drug regimens are assigned to the individual pathogens and an algorithm for the management of atypical infections in patients with asthma or recurrent wheezing is presented.

Common childhood viral infections

Infections caused by viruses are universal during childhood and adolescence. Clinicians will regularly care for children and adolescents who present with infections caused by a wide number of viral pathogens. These infections have varied presentations. Many infections may have clinical presentations that are specific to the infecting virus but present differently, based on the age and immunocompetence of the patient. Some children are directly impacted early in their lives when maternal disease results in an in utero infection (cytomegalovirus, rubella virus, or parvovirus B19). Other viruses may infect children in a predictable pattern as they grow older (rhinovirus or influenza virus). Fortunately, many viral infections frequently encountered in the past are no longer extant due to widespread immunization efforts. Recognition of these vaccine-preventable infections is important because outbreaks of some of these diseases (mumps or measles) continue to occur in the United States. Vigilance in vaccine programs against these viral agents can prevent their re-emergence. In addition, an increasing number of viral infections (herpes simplex virus, influenza virus, varicella zoster virus, or cytomegalovirus) can now be successfully treated with antiviral medications. Most viral infections in children result in self-limited illness and are treated symptomatically and infected children experience full recovery. This review will address the epidemiology, clinical presentation, diagnosis, treatment, and prevention of viral infections commonly encountered by the clinician.

Association between infant swimming and rhinovirus-induced wheezing

AIM

Infant swimming has been considered as a risk factor for wheezing, but the role that respiratory viruses play is unclear. We explored the effects of infant swimming on the risk of all wheezing illnesses and wheezing associated with rhinoviruses.

METHODS

We followed up a birth cohort of 1827 children until 17 months of age, collecting data on infant swimming, other risk factors and physician-diagnosed bronchiolitis or recurrent wheezing. Viral diagnostics were performed in a subset of children with all respiratory tract infections.

RESULTS

Data on infant swimming were obtained for 1038 children, with viral follow-up for 635 children. At least one wheezing illness was documented in 45/469 (9.6%) swimming children versus 39/569 (6.9%) nonswimming children (p = 0.11), and rhinoviruses were associated with wheezing in 11/296 (3.7%) swimming children versus 4/339 (1.2%) nonswimming children (p = 0.04). In adjusted logistic regression analyses, swimming had an odds ratio of 1.71 (p = 0.05) for bronchiolitis and 3.57 (p = 0.06) for rhinovirus-associated wheezing. An association between infant swimming and rhinovirus-associated wheezing was detected for children with atopic eczema (p = 0.006).

CONCLUSION

There may be a link between infant swimming and rhinovirus-induced wheezing illnesses in atopic infants.

Respiratory morbidity of preterm infants of less than 33 weeks gestation without bronchopulmonary dysplasia: a 12-month follow-up of the CASTOR study cohort

The aim of this study was to describe the incidence and risk factors for respiratory morbidity during the 12-month period following the first respiratory syncytial virus (RSV) season in 242 preterm infants [<33 weeks gestational age (GA)] without bronchopulmonary dysplasia and 201 full-term infants (39-41 weeks GA) from the French CASTOR study cohort. Preterm infants had increased respiratory morbidity during the follow-up period compared to full-terms; they were more likely to have wheezing (21% vs. 11%, P = 0·007) and recurrent wheezing episodes (4% vs. 1%, P = 0·049). The 17 infants (14 preterms, three full-terms) who had been hospitalized for RSV-confirmed bronchiolitis during their first RSV season had significantly more wheezing episodes during the follow-up period than subjects who had not been hospitalized for RSV-confirmed bronchiolitis (odds ratio 4·72, 95% confidence interval 1·71-13·08, P = 0·003). Male gender, birth weight <3330 g and hospitalization for RSV bronchiolitis during the infant's first RSV season were independent risk factors for the development of wheezing episodes during the subsequent 12-month follow-up period.

Wheezing in infancy

Several population-based birth cohort studies documented that 30% of children suffer from wheezing during respiratory infections before their third birthday. Infants are prone to wheeze because of anatomic factors related to the lung and chest wall in addition to immunologic and molecular influences in comparison to older children. Viral infections lead to immunologic derangements that cause wheezing both in immunocompetent and immunodeficient infants. Anatomic causes of wheeze may be extrinsic or intrinsic to the airway. Not every wheeze is indicative of asthma but prediction of asthma in persistent wheezers is possible. Testing for allergy in these infants is worthwhile and can be of significant value in avoidable allergens. Treatment of an infant with wheezing depends on the underlying etiology. Response to bronchodilators is unpredictable and a trial of inhaled steroids may be warranted in a patient who has responded to multiple courses of oral steroids, has moderate to severe wheezing, or a significant history of atopy including food allergy or eczema. Ribavirin administered by aerosol, hyper-immune respiratory syncytial virus immunoglobulin (RSV IVIG), and intramuscular monoclonal antibody to an RSV protein have been used for RSV bronchiolitis in infants with congenital heart disease or chronic lung disease.

Descriptive epidemiological features of bronchiolitis in a population-based cohort

OBJECTIVE

The goal was to investigate the epidemiological features of incident bronchiolitis by using a population-based infant cohort.

METHODS

Outpatient and inpatient health records were used to identify incident bronchiolitis cases among 93,058 singleton infants born in the Georgia Air Basin between 1999 and 2002. Additional health-related databases were linked to provide data on sociodemographic variables, maternal characteristics, and birth outcome measures.

RESULTS

From 1999 to 2002, bronchiolitis accounted for 12,474 incident health care encounters (inpatient or outpatient contacts) during the first year of life (134.2 cases per 1000 person-years). A total of 1588 hospitalized bronchiolitis cases were identified (17.1 cases per 1000 person-years). Adjusted Cox proportional-hazard analyses for both case definitions indicated an increased risk of incident bronchiolitis in the first year of life (follow-up period: 2-12 months) for boys, infants of First Nations status, infants with older siblings, and infants living in neighborhoods with smaller proportions of maternal postsecondary education. The risk also was elevated for infants born to young mothers (<20 years of age) or mothers who did not initiate breastfeeding in the hospital. Infants with low (1500-2400 g) or very low (<1500 g) birth weight and those with congenital anomalies also had increased risk. Maternal smoking during pregnancy increased the risk of hospitalized bronchiolitis.

CONCLUSIONS

This population-based study of the epidemiological features of bronchiolitis provides evidence for intervening with high-risk infants and their families. Clinical and public health interventions are recommended for the modifiable risk factors of maternal breastfeeding and smoking and for modification of vulnerable environments where possible (eg, limiting exposure to other young children), during high-risk periods such as the first few months of life or the winter season.

Efficacy of prednisolone in children hospitalized for recurrent wheezing

Data on the efficacy of corticosteroids on respiratory picornavirus-induced wheezing are limited. To determine whether prednisolone is effective in rhinovirus- or enterovirus-induced recurrent wheezing, we conducted a controlled trial comparing oral prednisolone (2 mg/kg/day in three divided doses for 3 days) with placebo in hospitalized wheezing children and studied post hoc virus-specific efficacy in early wheezing (<3 episodes, reported elsewhere) and in recurrent wheezing (>or=3 episodes). Virus-negative children where excluded. Our primary endpoint was the time until children were ready for discharge. Secondary endpoints included oxygen saturation and exhaled nitric oxide during hospitalization, duration of symptoms, blood eosinophil count, and impulse oscillometry 2 wk after discharge, and occurrence of relapses during the following 2 months. Virus-specific effects were analyzed with interaction analysis in a multivariate regression model. During the study period, 661 patients were hospitalized, 293 randomized, and 59 were accepted in this analysis (mean age 2.6 yr, s.d. 1.3). Prednisolone did not significantly decrease the time until ready for discharge in all patients (prednisolone vs. placebo, medians, 18 vs. 24 h, p = 0.11). However, prednisolone decreased the time until ready for discharge in children with picornavirus infection (respectively, 12 vs. 24 h, p = 0.0022) and more specifically, in children with enterovirus infection (6 vs. 35 h, p = 0.0007). In the secondary endpoints, prednisolone decreased the duration of cough and dyspnea in rhinovirus-affected children (p = 0.033 for both). Prospectively designed clinical trial is needed to test the hypothesis that prednisolone reduces symptoms in picornavirus-affected wheezing children.