Prospective multicenter study of the viral etiology of bronchiolitis in the emergency department

Substantial Burden of Nonmedically Attended RSV Infection in Healthy-Term Infants: An International Prospective Birth Cohort Study

BACKGROUND

During the first year of life, 1 in 4 infants develops a symptomatic respiratory syncytial virus (RSV) infection, yet only half seek medical attention. The current focus on medically attended RSV therefore underrepresents the true societal burden of RSV. We assessed the burden of nonmedically attended RSV infections and compared with medically attended RSV.

METHODS

We performed active RSV surveillance until the age of 1 year in a cohort (n = 993) nested within the Respiratory Syncytial Virus Consortium in EUrope (RESCEU) prospective birth cohort study enrolling healthy term-born infants in 5 European countries. Symptoms, medication use, wheezing, and impact on family life were analyzed.

RESULTS

For 97 of 120 (80.1%) nonmedically attended RSV episodes, sufficient data were available for analysis. In 50.5% (49/97), symptoms lasted ≥15 days. Parents reported impairment in usual daily activities in 59.8% (58/97) of episodes; worries, 75.3% (73/97); anxiety, 34.0% (33/97); and work absenteeism, 10.8% (10/93). Compared with medically attended RSV (n = 102, 9 hospital admissions), Respiratory Syncytial Virus NETwork (ReSViNET) severity scores were lower (3.5 vs 4.6, P < .001), whereas duration of respiratory symptoms and was comparable.

CONCLUSIONS

Even when medical attendance is not required, RSV infection poses a substantial burden to infants, families, and society. These findings are important for policy makers when considering the implementation of RSV immunization. Clinical Trials Registration. ClinicalTrials.gov (NCT03627572).

Management of Acute Bronchiolitis in Spoke Hospitals in Northern Italy: Analysis and Outcome

Bronchiolitis is an acute viral infection of the lower respiratory tract that affects infants and young children. Respiratory syncytial virus (RSV) is the most common causative agent; however, other viruses can be involved in this disease. We retrospectively reviewed the clinical features of infants aged less than 12 months hospitalized for acute bronchiolitis in our Pediatric Units of Chivasso, Cirié, and Ivrea in Piedmont, Northern Italy, over two consecutive bronchiolitis seasons (September 2021-March 2022 and September 2022-March 2023). Patient-, disease-, and treatment-related variables were analyzed. The probability of therapeutic success (discharge home) was 96% for all patients (93% for RSV vs. 98% for non-RSV patients, p > 0.05). Among 192 patients, 42 infants (22%) underwent high-flow oxygen support (HFNC), and only 8 (4%) needed to be transferred to our hub referral hospital. Factors associated with hub hospital transfer were the age under 1 month and the failure of HFNC. The wide and increasing use of HFNC in pediatric inpatients improved the management of bronchiolitis in Spoke hospitals, reducing transfer to a hub hospital provided with Intensive Care Units.

High incidence of the virus among respiratory pathogens in children with lower respiratory tract infection in northwestern China

Lower respiratory tract infection (LRTI) is one of the major reasons for childhood mortality that threaten the health of the public. We aimed to investigate the epidemiological pathogens and their infection analysis among children with LRTI. Sputum specimens were collected for polymerase chain reaction detection and microbiological tests to identify the viral infection and bacterial infection. The serological specimens were separated from venous blood using for Mycoplasma pneumoniae and Chlamydia pneumoniae detection. The virus was confirmed in 86.2% of the children. Human rhinovirus (38.3%), respiratory syncytial virus (32.1%), and parainfluenza virus type 3 (27.2%) were the most frequently identified pathogens. Patients with viral and bacterial coinfection showed younger age (p = 0.032), a higher proportion of wheezing rales (p = 0.032), three depressions sign (p = 0.028), and tachypnea (p = 0.038), and more likely associated with severe pneumonia (p = 0.035). Additionally, older children were more susceptible to viral-atypical bacterial coinfection (p = 0.032). Vomiting (p = 0.011) and fever (p = 0.003) were more likely to occur in children with viral-atypical bacterial coinfection. Attention should be paid to the virus infection of LRTI, as viral-bacterial coinfection and viral-atypical bacterial co-infection may have a detrimental impact on the gravity of LTRI.

Systematic review and meta-analysis of the prevalence of common respiratory viruses in children < 2 years with bronchiolitis in the pre-COVID-19 pandemic era

Introduction

The advent of genome amplification assays has allowed description of new respiratory viruses and to reconsider the role played by certain respiratory viruses in bronchiolitis. This systematic review and meta-analysis was initiated to clarify the prevalence of respiratory viruses in children with bronchiolitis in the pre-COVID-19 pandemic era.

Methods

We performed an electronic search through Pubmed and Global Index Medicus databases. We included observational studies reporting the detection rate of common respiratory viruses in children with bronchiolitis using molecular assays. Data was extracted and the quality of the included articles was assessed. We conducted sensitivity, subgroups, publication bias, and heterogeneity analyses using a random effect model.

Results

The final meta-analysis included 51 studies. Human respiratory syncytial virus (HRSV) was largely the most commonly detected virus 59.2%; 95% CI [54.7; 63.6]). The second predominant virus was Rhinovirus (RV) 19.3%; 95% CI [16.7; 22.0]) followed by Human bocavirus (HBoV) 8.2%; 95% CI [5.7; 11.2]). Other reported viruses included Human Adenovirus (HAdV) 6.1%; 95% CI [4.4; 8.0]), Human Metapneumovirus (HMPV) 5.4%; 95% CI [4.4; 6.4]), Human Parainfluenzavirus (HPIV) 5.4%; 95% CI [3.8; 7.3]), Influenza 3.2%; 95% CI [2.2; 4.3], Human Coronavirus (HCoV) 2.9%; 95% CI [2.0; 4.0]), and Enterovirus (EV) 2.9%; 95% CI [1.6; 4.5]). HRSV was the predominant virus involved in multiple detection and most codetections were HRSV + RV 7.1%, 95% CI [4.6; 9.9]) and HRSV + HBoV 4.5%, 95% CI [2.4; 7.3]).

Conclusions

The present study has shown that HRSV is the main cause of bronchiolitis in children, we also have Rhinovirus, and Bocavirus which also play a significant role. Data on the role played by SARS-CoV-2 in children with acute bronchiolitis is needed.

Review registration

PROSPERO, CRD42018116067.

Knowledge translation in Western Australia tertiary paediatric emergency department: An audit cycle of effectiveness of guideline dissemination on bronchiolitis management

AIM

Bronchiolitis is the commonest cause of hospitalisation for infants. Evidence-based Australasian bronchiolitis guideline was developed and introduced in 2017. This audit was to determine if the knowledge translation process of the updated local tertiary hospital bronchiolitis guideline (based on the Australasian guideline) reduced unnecessary interventions.

METHODS

A retrospective chart review of infants with bronchiolitis diagnosis during the pre-guideline (1 July to 31 August 2015) and post-guideline (1 July to 31 August 2017) period, with the primary outcome of the number/proportion of unnecessary interventions.

RESULTS

Presentations between 1 July to 31 August 2015 (n = 465) were compared with 2017 (n = 343). There was no difference in undertaking chest X-ray (24 (5.2%) vs. 17 (5.0%), odds ratio (OR) 0.98 (95% confidence interval (CI) 0.71-1.35), P = 0.911), salbutamol (23 (4.9%) vs. 10 (2.9%), OR 0.86 (95% CI 0.65-1.13), P = 0.279), glucocorticoids (2 (0.4%) vs. 5 (1.5%), OR 1.89 (95% CI 0.83-4.31), p = 0.129), antibiotics (11 (2.4%) vs. 5 (1.5%), OR 0.86 (95% CI 0.65-1.15), P = 0.307) or nasopharyngeal aspirate (172 (37%) vs. 124 (36.2%), OR 1.00 (95% CI 0.87-1.67), P = 0.937) in hospital. Adrenaline was not administered in both years. There was reduced hospital admissions (303 (65.2%) vs. 192 (56.0%), OR 0.82 (95% CI 0.71-0.95), P = 0.008) with no difference in paediatric intensive care unit admissions (10 (2.2%) vs. 8 (2.3%), OR 1.04 (95% CI 0.65-1.67), P = 0.863).

CONCLUSION

The dissemination process of the updated local hospital bronchiolitis guideline did not show any statistically significant reduction of unnecessary interventions in the hospital. Further studies are required to determine the effective process to instigate changes in health services.

Role of nebulized epinephrine in moderate bronchiolitis: a quasi-randomized trial

BACKGROUND/AIMS

Bronchiolitis is the most common lower respiratory illness that characteristically affects the children below 2 years of age accounting about 2-3% of patients admitted to hospital each year [1-4]. We compared the effect of racemic epinephrine (RE) and 3% hypertonic saline (HS) nebulization on the length of stay (LOS) in the hospital.

METHODS

We looked at the infants with moderate bronchiolitis, from October 2013 to March 2014. Out of eighty cases, 16 in HS and 18 in RE groups were enrolled. At the time of admission, 0.2 ml of RE added to 1.8 ml of distilled water was nebulized to RE group, as compared with 2 ml of 3% HS in nebulized form. RE was re-administered if needed on 6 h in comparison with 3% HS at the frequency of 1 to 4 h.

RESULTS

One infant from RE group and three infants from HS group were excluded due to progression towards severe bronchiolitis. The LOS in RE group ranged between 18 and 160 h (mean 45 h), while in HS group, LOS was 18.50-206 h (mean 74.3 h). The LOS was significantly short in RE group (p value 0.015) which was statistically significant.

CONCLUSION

Racemic epinephrine nebulization as first-line medication may significantly reduce the length of hospital stay in infants with moderate bronchiolitis in comparison with nebulized HS.

Nosocomial Infections in Patients Hospitalized with Respiratory Syncytial Virus: A Practice Review

Viral testing is not always recommended in children with bronchiolitis due to doubts concerning its prognostic use. In this retrospective study, we investigated how the RSV testing would influence the frequency of nosocomial infections (NI). The files of 305 children, hospitalized due to the respiratory syncytial virus (RSV) infection in the period 2010-2014, were reviewed in the study. We found ten cases of NI. The RSV preventive measures did not vary in the consecutive years investigated, but the number of viral tests substantially varied. In 2010, 2012, and 2014, when ca. 2 tests per RSV(+) patient were performed, the risk of NI per patient was 1.3%, while in 2011 and 2013, when the RSV testing was less frequent, the accumulated risk per patient was 5.2%. There was a strong adverse relationship between the number of tests performed and the number of NI (rho = -0.975). The children with NI, when compared to those without NI, required a longer hospital stay, generating higher hospital costs regarding treatment, productivity loss, and indirect costs. The expenditure for RSV testing in the years of a low NI risk was higher than that in the high-risk years. Conversely, the expenditure related to NI management was lower in the years of a low NI risk. Each euro spent on RSV testing saved over 26 € from the NI management expenditure. We conclude that RSV testing is needed in the hospital setting to isolate the infected children and to prevent nosocomial RSV spread. This strategy is health advantageous and requires less resources than NI treatment.

Assessing the potential of upper respiratory tract point-of-care testing: a systematic review of the prognostic significance of upper respiratory tract microbes

OBJECTIVES

Microbial point-of-care testing (POCT) has potential to revolutionize clinical care. Understanding the prognostic value of microbes identified from the upper respiratory tract (a convenient sampling site) is a necessary first step to understand potential for upper respiratory tract POCTs in assisting antimicrobial treatment decisions for respiratory infections (RTIs). The aim was to investigate the relationship between upper respiratory tract microbial detection and disease prognosis, including effects of antimicrobial use.

METHODS

Data sources were the MEDLINE and Embase databases. Study eligibility criteria consisted of quantitative studies reporting microbiological and prognostic data from patients of all age groups presenting with RTI. Patients presenting to healthcare or research settings with RTI participated. Interventions included upper respiratory tract swab. The methods used were systematic review and meta-analysis.

RESULTS

Searches identified 5156 articles, of which 754 were duplicates and 4258 excluded on title or abstract. A total of 144 full texts were screened; 21 articles were retained. Studies reported data for 15 microbes and 26 prognostic measures (390 potential associations). One hundred and seven (27%) associations were investigated statistically, of which 38 (36%) were significant. Most studies reported only prognostic value of test positive results. Meta-analyses suggested hospitalization duration was longer for patients with respiratory syncytial virus than adenovirus and influenza, but significant heterogeneity was observed between studies.

CONCLUSIONS

A quarter of potential prognostic associations have been investigated. Of these, a third were significant, suggesting considerable potential for POCT. Future research should investigate prognostic value of positive and negative tests, and interactions between test results, use of antimicrobials and microbial resistance.

Risk Factors and Clinical Determinants in Bronchiolitis of Infancy

OBJECTIVES

The aims of this study was to demonstrate the viral pathogens, to evaluate the clinical prognosis, risk factors for recurrence, severity of acute viral bronchiolitis episodes among pediatric patients.

MATERIALS AND METHODS

Our study included 101 children aged between 2 months and 2 years diagnosed with clinical bronchiolitis between September 2011 and April 2012. The demographics and clinical, laboratory, and radiological results of the patients were recorded. Nasopharyngeal swab samples were collected and analyzed through polymerase chain reaction (PCR) method. The patients were followed up for at least one year for new episodes, existence of wheezing, frequency of pulmonary infections, and progression of asthma.

RESULTS

In half of the patients, determinants were indicated through the PCR method, with the most frequent being respiratory syncytial virus (44%). The frequency of bronchiolitis was higher in prematures (p<0.005). There was a relationship between crowded family structure and the existence of wheezing (p=0.003), increased recurrence (p=0.014), and need for inhaler treatment (p=0.014). The frequency was higher in patients living in urban cities (p<0.001), in houses with heating stoves (p=0.001), and in houses with smokers (p=0.001). Patients living in houses with heating stoves had more severe episodes (p=0.018). Recurrent wheezing and the need for regular inhaler usage were positively correlated with high API scores (p=0.008 and p=0.002, respectively).

CONCLUSION

Prematurity, exposure to smoking, living in a crowded house with heating stoves, and an urban life are the risk factors for frequent bronchiolitis. The API can be used to predict the recurrence of bronchiolitis.

Is multiple viral infection a predictor of severity in children with acute bronchiolitis?

Background:

Acute bronchiolitis is a common cause of pediatric emergency department admissions in children younger than 2.

Objectives:

The study aimed to compare the outcomes and the severity of bronchiolitis in young children with multiple simultaneous respiratory virus infections to those with single virus infection and no virus identified group.

Methods:

Patients with moderate and severe bronchiolitis who visited our emergency department between November 2016 and May 2017 had nasopharyngeal swab samples results tested by multiplex polymerase chain reaction were included in the study. Patients’ characteristics, clinical severity of illness, and outcome (pediatric emergency department discharge, admission to ward or pediatric intensive care unit) were compared with the detected viral agents.

Results:

A total of 241 patients were included in the study. The mean age was 7.8 ± 2.6 months and 147 (61%) were male. Respiratory syncytial virus was the most common detected viral agent in 108 (39%) cases followed by human rhinoviruses in 67 (24%). Respiratory syncytial virus was found more frequently in February and March (p = 0.002). Leukocytosis and pneumonia were more likely observed in patients with only human rhinoviruses (+) subjects (p = 0.010 and p = 0.015, respectively). Intensive care hospitalization rate (16%) was higher in patients with multiple viral agents (p = 0.004).

Conclusions:

Respiratory syncytial virus remains the most common detected viral agent in acute bronchiolitis patients. While the pathogens detected were seasonally different, there was a significant relationship between leukocytosis, bacterial pneumonia, and detected viral agents. The disease was more severe in patients with multiple viral agents.

Point-of-care lung ultrasound in infants with bronchiolitis in the pediatric emergency department: a prospective study

Bronchiolitis is the most common cause of hospitalization of children in the first year of life. The lung ultrasound is a new diagnostic tool which is inexpensive, non-invasive, rapid, and easily repeatable. Our prospective study was conducted in the emergency department and all patients underwent a routine clinical evaluation and lung ultrasound by the pediatricians who defined the clinical and the ultrasound score. We enrolled 76 infants (median age 90 days [IQR 62-183], 53.9% males). In nasopharyngeal aspirates, the respiratory syncytial virus was isolated in 33 patients. Considering the clinical score, children with higher score had a higher probability of requiring respiratory support (p 0.001). At the ultrasound evaluation, there was a significant difference on ultrasound score between those who will need respiratory support or not (p 0.003). Infants who needed ventilation with helmet continuous positive airway pressure had a more severe ultrasound score (p 0.028) and clinical score (p 0.004), if compared with those who did not need it.Conclusion: Our study shows that lung ultrasound in the bronchiolitis may be a useful method to be integrated with the clinical evaluation to better define the prognosis of the individual patient. Multicenter studies on larger populations are necessary to confirm our data. What is Known: • Bronchiolitis is the main cause of lower respiratory tract infection in children younger than 24 months. • Ultrasound can evaluate the lung parenchyma without ionizing radiations. What is New: • Lung ultrasound may be a useful diagnostic tool to define the prognosis of the infants affected by bronchiolitis if performed at the first assessment in the emergency department. • The score obtained at the ultrasound evaluation is higher in those who will need oxygen therapy during admission for more time and in those who will need respiratory support with helmet continuous positive airway pressure.

Improving Evidence Based Bronchiolitis Care

Bronchiolitis is the number one cause of hospitalization in infants during the first year of life. Clinical guidelines recommend primarily supportive care and discourage use of pharmacotherapies and diagnostics. However, there continues to be widespread use of non-recommended therapies and variation in the use of therapeutic interventions among hospitals in the United States. Here we review evidence-based management of this common disease in order to optimize resource utilization, decrease healthcare costs, and decrease unnecessary hospitalization. Current evidence does not support the routine use of chest radiographs, viral testing or laboratory evaluation in children with bronchiolitis. In addition, routine administration of bronchodilators, including albuterol and nebulized epinephrine, corticosteroids and hypertonic saline are not recommended for infants and children with bronchiolitis. Intravenous or nasogastric hydration and nutritional support, supplemental oxygen, and respiratory support are recommended. Standardization of bronchiolitis care with evidence based institutional clinical pathways spanning ED to inpatient care can help optimize resource utilization while simultaneously improving care of bronchiolitis and reducing hospital length of stays and costs.

Nebulized hypertonic saline in infants hospitalized with moderately severe bronchiolitis due to RSV infection: A multicenter randomized controlled trial

INTRODUCTION

The efficacy of nebulized hypertonic saline (HS) therapy for shortening hospital length of stay (LOS) or improving bronchiolitic symptoms remains controversial. Most studies enrolled small numbers of subjects and did not consider the role of respiratory syncytial virus (RSV), the most common cause of acute bronchiolitis. Our aim was to evaluate the efficacy and safety of nebulized HS therapy for acute bronchiolitis due to RSV in moderately ill hospitalized infants.

MATERIALS AND METHODS

This was an open-label, multicenter, randomized controlled trial comparing a nebulized HS treatment group with a normal saline (NS) group. The subjects, 128 infants with bronchiolitis due to RSV, were admitted to five hospitals in Tokyo, Japan. Three-percent HS or NS was administered via bronchodilator four times daily post-admission. The primary outcome was LOS, defined as the time until the patients fulfilled the discharge criteria, namely, absence of fever, no need for supplemental oxygen, and adequate feeding. Survival analysis was conducted in accordance with the intention-to-treat principle.

RESULTS

The baseline characteristics were similar between the two groups. There was no significant overall difference in LOS between the groups (4.81 ± 2.14 days in HS vs 4.61 ± 2.18 days in NS; P = 0.60). Survival analysis by log-rank test also showed no significance (P = 0.62). Multivariate adjustment did not significantly alter the results. The treatment was well-tolerated, with no adverse effects attributable to the use of HS.

CONCLUSIONS

Nebulized HS therapy did not significantly reduce LOS among infants with bronchiolitis due to RSV.

Serum LL-37 Levels Associated With Severity of Bronchiolitis and Viral Etiology

Background

LL-37 is a host defense peptide with antimicrobial and immunomodulatory properties. We examined the relation of serum LL-37 levels to the severity of bronchiolitis and viral etiology.

Methods

We performed a 17-center prospective cohort study in infants hospitalized with bronchiolitis over 3 winters (2011-2014). Site teams collected clinical data, nasopharyngeal aspirates and serum. We used real-time polymerase chain reaction to test nasopharyngeal aspirates for 16 viruses. We tested serum for LL-37. Severity of bronchiolitis was defined by intensive care use and hospital length of stay. Viral etiology was defined as respiratory syncytial virus (RSV) or rhinovirus (RV), including coinfections with other viruses.

Results

The median age of the 1005 enrolled infants was 3 months (interquartile range, 2-6 months). After adjustment for 12 variables, LL-37 levels in the lowest quartile, compared with the highest, were associated both with intensive care use (adjusted odds ratio [aOR], 1.97; P = .01) and longer hospital stay (1.34; P < .001). In separate multivariable models, infants with LL-37 levels in the lowest 3 quartiles, compared with the highest, were more likely to have RSV (eg, aOR, 2.6 [lowest quartile]; P < .001 [all quartiles]). By contrast, infants with the lowest 3 LL-37 quartiles were less likely to have RV (eg, aOR, 0.5 [lowest quartile]; Pall quartiles ≤ .03 [all quartiles]).

Conclusions

In a large multicenter study of infants hospitalized with bronchiolitis, lower levels of serum LL-37 were associated with increased severity of illness. There was also an inverse relationship between LL-37 levels and the most common virus causing bronchiolitis, RSV. These findings highlight the role of LL-37 in the pathogenesis of bronchiolitis.

Bronchiolitis: From Practice Guideline to Clinical Practice

The American Academy of Pediatrics' clinical practice guideline in bronchiolitis was last updated in 2014 with recommendations to improve care for pediatric patients with bronchiolitis. As most treatments of bronchiolitis are supportive, the guideline minimizes the breadth of treatments previously used and cautions the use of tests and therapies that have a limited evidence base. Emergency physicians must be familiar with the guidelines in order to apply best practices appropriately.

Impact of meteorological factors on the emergence of bronchiolitis in North-western Greece

OBJECTIVE

To evaluate the relationship between meteorological factors in North-western Greece and the incidence of bronchiolitis.

METHODS

Meteorological data (air temperature and rainfall) for Ioannina city in North-western Greece and medical data from hospitalised patients at University Hospital of Ioannina were collected between January 2002 and December 2013. The association between meteorological factors and rate of hospitalisation due to bronchiolitis was investigated. The data processing was done using the Pearson product-moment correlation coefficient and applying the chi-square test at contingency tables of the parameters.

RESULTS

Of the 792 hospitalised cases, 670 related to infants (<1 year) and 122 concerned patients aged 1-2 years old. The disease is more common among boys (59.5%) than girls (40.5%). The disease course through the year has a double variation with a main maximum in March and a main minimum in August. The statistical study showed statistically significant correlation of bronchiolitis with: (a) the temperature parameters on an annual basis; (b) precipitation in autumn and dryness in spring; and (c) with sudden changes in diurnal temperature range on an annual basis.

CONCLUSION

A peak incidence of bronchiolitis was noticed in cold and wet seasons during the five days preceding hospitalisation.

The respiratory system in pediatric chronic heart disease

Cardiovascular disease in the pediatric population closely affects the respiratory system inducing water retention in the lungs and pulmonary edema, airway compression by cardiovascular structures, restrictive pulmonary physiology as a result of hemodynamic changes and surgical repair, susceptibility to respiratory infections, development of pulmonary hypertension, thrombosis, or hemorrhage. Chronic heart failure and congenital heart disease are characterized by various respiratory manifestations and symptoms mimicking lung disease, which are frequently difficult to diagnose and treat. Pulmonary function is multiply affected in pediatric heart disease with mostly restrictive but also obstructive and diffusion abnormalities. Patients with Fontan circulation represent a separate group with slow, passive pulmonary blood flow and distinct pathophysiology with low cardiac output heart failure, restrictive lung pattern, increased thromboembolic complications and rare conditions such as protein losing enteropathy and plastic bronchitis. Distinguishing between cardiovascular and pulmonary symptoms may be challenging in the growing population of pediatric and adult survivors of congenital heart disease and understanding of the relationship of the two systems in heart disease is crucial for the optimal management of these patients.

Role of viral infections in the development and exacerbation of asthma in children

Viral infections are closely linked to wheezing illnesses in children of all ages. Respiratory syncytial virus (RSV) is the main causative agent of bronchiolitis, whereas rhinovirus (RV) is most commonly detected in wheezing children thereafter. Severe respiratory illness induced by either of these viruses is associated with subsequent development of asthma, and the risk is greatest for young children who wheeze with RV infections. Whether viral illnesses actually cause asthma is the subject of intense debate. RSV-induced wheezing illnesses during infancy influence respiratory health for years. There is definitive evidence that RSV-induced bronchiolitis can damage the airways to promote airway obstruction and recurrent wheezing. RV likely causes less structural damage and yet is a significant contributor to wheezing illnesses in young children and in the context of asthma. For both viruses, interactions between viral virulence factors, personal risk factors (eg, genetics), and environmental exposures (eg, airway microbiome) promote more severe wheezing illnesses and the risk for progression to asthma. In addition, allergy and asthma are major risk factors for more frequent and severe RV-related illnesses. Treatments that inhibit inflammation have efficacy for RV-induced wheezing, whereas the anti-RSV mAb palivizumab decreases the risk of severe RSV-induced illness and subsequent recurrent wheeze. Developing a greater understanding of personal and environmental factors that promote more severe viral illnesses might lead to new strategies for the prevention of viral wheezing illnesses and perhaps reduce the subsequent risk for asthma.

Comparison of cytokine expression profiles in infants with a rhinovirus induced lower respiratory tract infection with or without wheezing: a comparison with respiratory syncytial virus

PURPOSE

The aim of this study was to evaluate whether infants with rhinovirus (RV) infection-induced wheezing and those with respiratory syncytial virus (RSV) infection-induced wheezing have different cytokine profiles in the acute stage.

METHODS

Of the infants with lower respiratory tract infection (LRTI) between September 2011 and May 2012, 88 were confirmed using reverse transcription polymerase chain reaction and hospitalized. Systemic interferon-gamma (IFN-γ), interleukin (IL)-2, IL-12, IL-4, IL-5, IL-13, and Treg-type cytokine (IL-10) responses were examined with multiplex assay using acute phase serum samples.

RESULTS

Of the 88 patients, 38 had an RV infection (RV group) and 50 had an RSV infection (RSV group). In the RV group, the IFN-γ and IL-10 concentrations were higher in the patients with than in the patients without wheezing (P=0.022 and P=0.007, respectively). In the RSV group, the differences in IFN-γ and IL-10 concentrations did not reach statistical significance between the patients with and the patients without wheezing (P=0.105 and P=0.965, respectively). The IFN-γ and IL-10 concentrations were not significantly different between the RV group with wheezing and the RSV group with wheezing (P=0.155 and P=0.801, respectively), in contrast to the significant difference between the RV group without wheezing and the RSV group without wheezing (P=0.019 and P=0.035, respectively).

CONCLUSION

In comparison with RSV-induced LRTI, RV-induced LRTI combined with wheezing showed similar IFN-γ and IL-10 levels, which may have an important regulatory function.

Marked variability observed in inpatient management of bronchiolitis in three Finnish hospitals

AIM

Infants hospitalised for bronchiolitis undergo examinations and treatments not supported by current research evidence and we investigated practice variations with regard to Finnish children under the age of two.

METHODS

This prospective, multicentre cohort study was conducted in paediatric units in three university hospitals in Finland from 2008 to 2010. Hospital medical records were reviewed to collect data on clinical course, testing and treatment. Data were analysed separately for children meeting our strict definition of bronchiolitis, aged under 12 months without a history of wheezing, and a loose definition, aged 12-23 months or with a history of wheezing.

RESULTS

The median age of the 408 children was 8.1 months. Clinical management varied between the three hospitals when stratified by strict and loose bronchiolitis subgroup definitions: complete blood counts ranged from 15-95% vs 16-94%, respectively, and the other measures were chest x-ray (16-91% vs 14-72%), intravenous fluids (2-47% vs 2-41%), use of nebulised epinephrine (10-84% vs 7-50%), use of salbutamol (18-21% vs 13-84%) and use of corticosteroids (6-23% vs 60-76%).

CONCLUSION

The clinical management of bronchiolitis varied considerably with regard to the three hospitals and the two definitions of bronchiolitis. A stronger commitment to evidence-based bronchiolitis guidelines is needed in Finland.

Viral bronchiolitis

Viral bronchiolitis is a common clinical syndrome affecting infants and young children. Concern about its associated morbidity and cost has led to a large body of research that has been summarised in systematic reviews and integrated into clinical practice guidelines in several countries. The evidence and guideline recommendations consistently support a clinical diagnosis with the limited role for diagnostic testing for children presenting with the typical clinical syndrome of viral upper respiratory infection progressing to the lower respiratory tract. Management is largely supportive, focusing on maintaining oxygenation and hydration of the patient. Evidence suggests no benefit from bronchodilator or corticosteroid use in infants with a first episode of bronchiolitis. Evidence for other treatments such as hypertonic saline is evolving but not clearly defined yet. For infants with severe disease, the insufficient available data suggest a role for high-flow nasal cannula and continuous positive airway pressure use in a monitored setting to prevent respiratory failure.

Nebulized epinephrine for young children with bronchiolitis

QUESTION

Every winter I see infants with flulike symptoms and wheezing. I frequently diagnose them with bronchiolitis based on their presenting symptoms. Would it be prudent to send those infants to the nearest emergency department for treatment with nebulized epinephrine?

ANSWER

Nebulized epinephrine should not be routinely used in infants with bronchiolitis. It is an option to consider in those with severe symptoms. If it is given and there are no signs of improvement, further doses are discouraged. Ongoing studies of epinephrine combined with other agents (eg, hypertonic saline, oral dexamethasone) are needed to confirm their benefit.

[Not Available]

Question Tous les ans, durant l’hiver, je vois des nourrissons qui présentent des symptômes pseudo-grippaux et des sibilances. Je pose souvent un diagnostic de bronchiolite en fonction du tableau clinique. Serait-il prudent d’envoyer ces nourrissons à l’urgence la plus proche pour recevoir un traitement par nébulisation d’épinéphrine?

Réponse La nébulisation d’épinéphrine ne doit pas être administrée systématiquement aux nourrissons atteints de bronchiolite. C’est une option à envisager chez les patients qui manifestent des symptômes graves. S’il n’y a aucun signe d’amélioration après l’administration d’épinéphrine, les doses subséquentes sont déconseillées. Il est nécessaire de poursuivre les études sur l’épinéphrine associée à d’autres agents (p. ex. solution saline hypertonique, dexaméthasone par voie orale) pour en confirmer les bienfaits.

Transcriptome assists prognosis of disease severity in respiratory syncytial virus infected infants

Respiratory syncytial virus (RSV) causes infections that range from common cold to severe lower respiratory tract infection requiring high-level medical care. Prediction of the course of disease in individual patients remains challenging at the first visit to the pediatric wards and RSV infections may rapidly progress to severe disease. In this study we investigate whether there exists a genomic signature that can accurately predict the course of RSV. We used early blood microarray transcriptome profiles from 39 hospitalized infants that were followed until recovery and of which the level of disease severity was determined retrospectively. Applying support vector machine learning on age by sex standardized transcriptomic data, an 84 gene signature was identified that discriminated hospitalized infants with eventually less severe RSV infection from infants that suffered from most severe RSV disease. This signature yielded an area under the receiver operating characteristic curve (AUC) of 0.966 using leave-one-out cross-validation on the experimental data and an AUC of 0.858 on an independent validation cohort consisting of 53 infants. A combination of the gene signature with age and sex yielded an AUC of 0.971. Thus, the presented signature may serve as the basis to develop a prognostic test to support clinical management of RSV patients.

Clinical presentation and microbiological diagnosis in paediatric respiratory tract infection: a systematic review

BACKGROUND

Antibiotic prescribing decisions for respiratory tract infection (RTI) in primary care could be improved if clinicians could target bacterial infections. However, there are currently no evidence-based diagnostic rules to identify microbial aetiology in children presenting with acute RTIs.

AIM

To analyse evidence of associations between clinical symptoms or signs and detection of microbes from the upper respiratory tract (URT) of children with acute cough.

DESIGN AND SETTING

Systematic review and meta-analysis.

METHOD

A literature search identified articles reporting relationships between individual symptoms and/or signs, and microbes detected from URT samples. Associations between pathogens and symptoms or signs were summarised, and meta-analysis conducted where possible.

RESULTS

There were 9984 articles identified, of which 28 met inclusion criteria. Studies identified 30 symptoms and 41 signs for 23 microbes, yielding 1704 potential associations, of which only 226 (13%) have presently been investigated. Of these, relevant statistical analyses were presented for 175 associations, of which 25% were significant. Meta-analysis demonstrated significant relationships between respiratory syncytial virus (RSV) detection and chest retractions (pooled odds ratio [OR] 1.9, 95% confidence interval [CI] = 1.6 to 2.3), wheeze (pooled OR 1.7, 95% CI = 1.5 to 2.0), and crepitations/crackles (pooled OR 1.7, 95% CI = 1.3 to 2.2).

CONCLUSIONS

There was an absence of evidence for URT pathogens other than RSV. The meta-analysis identified clinical signs associated with RSV detection, suggesting clinical presentation may offer some, albeit poor, diagnostic value. Further research is urgently needed to establish the value of symptoms and signs in determining microbiological aetiology and improve targeting of antibiotics in primary care.

Rhinovirus-C detection in children presenting with acute respiratory infection to hospital in Brazil

Human rhinovirus (RV) is a common cause of acute respiratory infection (ARI) in children. We aimed to characterize the clinical and demographic features associated with different RV species detected in children attending hospital with ARI, from low‐income families in North‐east Brazil. Nasopharyngeal aspirates were collected from 630 children <5 years with ARI. Clinical diagnosis and disease severity were also recorded. Samples were analyzed by multiplex PCR for 18 viral and atypical bacterial pathogens; RV positive samples underwent partial sequencing to determine species and type. RV was the fourth commonest pathogen accounting for 18.7% of pathogens detected. RV was commonly detected in children with bronchiolitis, pneumonia, and asthma/episodic viral wheeze (EVW). Species and type were assigned in 112 cases (73% RV‐A; 27% RV‐C; 0% RV‐B). Generally, there were no differences in clinical or demographic characteristics between those infected with RV‐A and RV‐C. However, in children with asthma/EVW, RV‐C was detected relatively more frequently than RV‐A (23% vs. 5%; P = 0.04). Our findings highlight RV as a potentially important pathogen in this setting. Generally, clinical and demographic features were similar in children in whom RV‐A and C species were detected. However, RV‐C was more frequently found in children with asthma/EVW than RV‐A. J. Med. Virol. 88:58–63, 2016. © 2015 Wiley Periodicals, Inc.

Demographic, Clinical and Hematological Profile of Children with Bronchiolitis: A Comparative Study between Respiratory Synctial Virus [RSV] and [Non RSV] Groups

INTRODUCTION

Acute bronchiolitis is one of major disease affecting the lower airways in infants and children with Respiratory Syncitial Virus (RSV) being most common causative organism accounting for 50%-80% of bronchiolitis cases.

AIM

To analyse the demographic characteristics, clinical features and haematological profile of children with Bronchiolitis. To compare the findings of demographic characteristics, clinical features and haematological profile between RSV and Non -RSV bronchiolitis.

MATERIALS AND METHODS

This is a prospective study, conducted in a teritiary care center for 1 year period from Jan 2015 to Dec 2015. The demographic characteristics, clinical features and haematological profile of children aged between 1 month to 3 years who fulfilled the inclusion criteria were noted in predesigned proforma, nasopharyngeal swab was sent for RSV analysis and then the findings of the parameters were compared between the two groups of RSV bronchiolitis and Non RSV bronchiolitis.

RESULTS

Among 80 cases with 40 in each group, children below the age of 1year were affected more in RSV group, with male preponderance. Among the clinical features except that 89.7% of RSV cases had wheeze that was statistically significant with no difference in other features. Investigations showed no much difference in both the groups. Percentage of Non RSV subjects who received nebulisation with bronchodilators, steroid and antibiotic therapy were higher than RSV subjects. The hospital stay was significantly higher in RSV cases and none of the study participants met with mortality.

CONCLUSION

Children with RSV bronchiolitis had prolonged hospital stay compared to Non RSV group. Need for nebulisation with bronchodilators, steroids and antibiotic therapy was more in Non RSV group.

Rhinovirus species and clinical features in children hospitalised with pneumonia from Mozambique

Objectives

To describe the prevalence of human rhinovirus (RV) species in children hospitalised with pneumonia in Manhiça, Mozambique, and the associations between RV species and demographic, clinical and laboratory features.

Methods

Nasopharyngeal aspirates were collected from children 0 to 10 years of age (n = 277) presenting to Manhiça District Hospital with clinical pneumonia. Blood samples were collected for HIV and malaria testing, blood culture and full blood counts, and a chest X‐ray was performed. A panel of common respiratory viruses was investigated using two independent multiplex RT‐PCR assays with primers specific for each virus and viral type. RV species and genotypes were identified by seminested PCR assays, sequencing and phylogenetic tree analyses.

Results

At least one respiratory virus was identified in 206 (74.4%) children hospitalised with clinical pneumonia. RV was the most common virus identified in both HIV‐infected (17 of 38, 44.7%) and HIV‐uninfected (74 of 237, 31.2%; P = 0.100) children. RV‐A was the most common RV species identified (47 of 275, 17.0%), followed by RV‐C (35/275, 12.6%) and RV‐B (8/275, 2.9%). Clinical presentation of the different RV species was similar and overlapping, with no particular species being associated with specific clinical features.

Conclusions

RV‐A and RV‐C were the most common respiratory viruses identified in children hospitalised with clinical pneumonia in Manhiça. Clinical presentation of RV‐A and RV‐C was similar and overlapping.

Children Hospitalized with Rhinovirus Bronchiolitis Have Asthma-Like Characteristics

Children with bronchiolitis often are considered a homogeneous group. However, in a multicenter, prospective study of 2207 young children hospitalized for bronchiolitis, we found that children with respiratory syncytial virus detected differ from those with rhinovirus detected; the latter patients resemble older children with asthma, including more frequent treatment with corticosteroids.

Does Viral Co-Infection Influence the Severity of Acute Respiratory Infection in Children?

Background

Multiple viruses are often detected in children with respiratory infection but the significance of co-infection in pathogenesis, severity and outcome is unclear.

Objectives

To correlate the presence of viral co-infection with clinical phenotype in children admitted with acute respiratory infections (ARI).

Methods

We collected detailed clinical information on severity for children admitted with ARI as part of a Spanish prospective multicenter study (GENDRES network) between 2011–2013. A nested polymerase chain reaction (PCR) approach was used to detect respiratory viruses in respiratory secretions. Findings were compared to an independent cohort collected in the UK.

Results

204 children were recruited in the main cohort and 97 in the replication cohort. The number of detected viruses did not correlate with any markers of severity. However, bacterial superinfection was associated with increased severity (OR: 4.356; P-value = 0.005), PICU admission (OR: 3.342; P-value = 0.006), higher clinical score (1.988; P-value = 0.002) respiratory support requirement (OR: 7.484; P-value < 0.001) and longer hospital length of stay (OR: 1.468; P-value < 0.001). In addition, pneumococcal vaccination was found to be a protective factor in terms of degree of respiratory distress (OR: 2.917; P-value = 0.035), PICU admission (OR: 0.301; P-value = 0.011), lower clinical score (-1.499; P-value = 0.021) respiratory support requirement (OR: 0.324; P-value = 0.016) and oxygen necessity (OR: 0.328; P-value = 0.001). All these findings were replicated in the UK cohort.

Conclusion

The presence of more than one virus in hospitalized children with ARI is very frequent but it does not seem to have a major clinical impact in terms of severity. However bacterial superinfection increases the severity of the disease course. On the contrary, pneumococcal vaccination plays a protective role.

Imaging Acute Airway Obstruction in Infants and Children

Acute airway obstruction is much more common in infants and children than in adults because of their unique anatomic and physiologic features. Even in young patients with partial airway occlusion, symptoms can be severe and potentially life-threatening. Factors that predispose children to airway compromise include the orientation of their larynx, the narrow caliber of their trachea, and their weak intercostal muscles. Because the clinical manifestations of acute airway obstruction are often nonspecific, clinicians often rely on the findings at imaging to establish a diagnosis. Several key anatomic features of the pediatric airway make it particularly susceptible to respiratory distress, and the imaging recommendations for children suspected of having acute airway obstruction are presented. Although cross-sectional imaging may be helpful, the diagnosis can often be established by using radiographs alone. Radiographs of the chest and upper airway should be routinely acquired; however, for the child who is in severe distress, a single lateral radiographic view may be all that is necessary. The purpose of this article is to provide an imaging approach to acquired causes of acute airway obstruction in children, including (a) abnormalities affecting the upper portion of the airway, such as croup, acute epiglottitis, retropharyngeal infection, and foreign bodies, and (b) abnormalities affecting the lower portion of the airway, such as asthma, bronchiolitis, and foreign bodies. It is essential that the radiologist recognize key imaging findings and understand the pathophysiologic features of acute airway obstruction because in most cases, when the cause is identified, the condition responds well to prompt management.

Clinical Endpoints for Respiratory Syncytial Virus Prophylaxis Trials in Infants and Children in High-income and Middle-income Countries

Respiratory syncytial virus (RSV) continues to cause significant clinical and economic burden around the world. Historically, RSV-associated hospitalization was used as a primary endpoint for RSV prophylaxis trials in infants. However, because of the changing epidemiology and healthcare system landscape, this endpoint has become a critical bottleneck on the pathway to licensure for new therapeutics. A panel of 7 RSV experts was convened (Chicago, IL, May 22, 2014) to evaluate the challenges of defining RSV prevention endpoints for clinical trials and to develop endpoints that are clinically meaningful while minimizing subjectivity and bias to achieve sufficient consistency of response for regulatory approval. Particular consideration was given to the ability to collect data systematically and consistently in countries with different healthcare practices and systems, while capturing the greatest proportion of disease impact. The group consensus was that a clinically meaningful primary endpoint could include medically attended RSV illness in settings beyond RSV-associated hospitalizations alone, in particular, a composite reduction in hospitalization, emergency room or urgent care center visits because of an RSV respiratory infection. Relevant secondary endpoints included reductions in RSV lower respiratory tract infection, RSV-related intensive care unit rates, subsequent recurrent wheezing or asthma and direct and indirect costs.

Recent advances in the management of acute bronchiolitis

Acute bronchiolitis is characterized by acute wheezing in infants or children and is associated with signs or symptoms of respiratory infection; it is rarely symptomatic in adults and the most common etiologic agent is respiratory syncytial virus (RSV). Usually it does not require investigation, treatment is merely supportive and a conservative approach seems adequate in the majority of children, especially for the youngest ones (<3 months); however, clinical scoring systems have been proposed and admission in hospital should be arranged in case of severe disease or a very young age or important comorbidities. Apnea is a very important aspect of the management of young infants with bronchiolitis. This review focuses on the clinical, radiographic, and pathologic characteristics, as well as the recent advances in management of acute bronchiolitis.

Adults hospitalised with acute respiratory illness rarely have detectable bacteria in the absence of COPD or pneumonia; viral infection predominates in a large prospective UK sample

OBJECTIVES

Many adult patients hospitalised with acute respiratory illness have viruses detected but the overall importance of viral infection compared to bacterial infection is unclear.

METHODS

Patients were recruited from two acute hospital sites in Leicester (UK) over 3 successive winters. Samples were taken for viral and bacterial testing.

RESULTS

Of the 780 patients hospitalised with acute respiratory illness 345 (44%) had a respiratory virus detected. Picornaviruses were the most commonly isolated viruses (detected in 23% of all patients). Virus detection rates exceeded 50% in patients with exacerbation of asthma (58%), acute bronchitis and Influenza-like-illness (64%), and ranged from 30 to 50% in patients with an exacerbation of COPD (38%), community acquired pneumonia (36%) and congestive cardiac failure (31%). Bacterial detection was relatively frequent in patients with exacerbation of COPD and pneumonia (25% and 33% respectively) but was uncommon in all other groups. Antibiotic use was high across all clinical groups (76% overall) and only 21% of all antibiotic use occurred in patients with detectable bacteria.

CONCLUSIONS

Respiratory viruses are the predominant detectable aetiological agents in most hospitalised adults with acute respiratory illness. Antibiotic usage in hospital remains excessive including in clinical conditions associated with low rates of bacterial detection. Efforts at reducing excess antibiotic use should focus on these groups as a priority. Registered International Standard Controlled Trial Number: 21521552.

Clinical practice guideline: the diagnosis, management, and prevention of bronchiolitis

This guideline is a revision of the clinical practice guideline, "Diagnosis and Management of Bronchiolitis," published by the American Academy of Pediatrics in 2006. The guideline applies to children from 1 through 23 months of age. Other exclusions are noted. Each key action statement indicates level of evidence, benefit-harm relationship, and level of recommendation. Key action statements are as follows:

Rhinovirus and the developing lung

Human rhinovirus (HRV) infections are now widely accepted as the commonest cause of acute respiratory illnesses (ARIs) in children. Advanced PCR techniques have enabled HRV infections to be identified as causative agents in most common ARIs in childhood including bronchiolitis, acute asthma, pneumonia and croup. However, the long-term implications of rhinovirus infections are less clear. The aim of this review is to examine the relationship between rhinovirus infections and disorders of the lower airways in childhood.

Bronchiolitis

This article discusses and evaluates the management options for children with bronchiolitis, and identifies children at high risk of a clinically severe illness.

Multicenter study of viral etiology and relapse in hospitalized children with bronchiolitis

BACKGROUND

It is unclear whether the infectious etiology of severe bronchiolitis affects short-term outcomes, such as posthospitalization relapse. We tested the hypothesis that children hospitalized with rhinovirus (RV) bronchiolitis, either as a sole pathogen or in combination with respiratory syncytial virus (RSV), are at increased risk of relapse.

METHODS

We performed a 16-center, prospective cohort study of hospitalized children age <2 years with bronchiolitis. During the winters of 2007-2010, researchers collected clinical data and nasopharyngeal aspirates from study participants; the aspirates were tested using real-time polymerase chain reaction. The primary outcome was bronchiolitis relapse (urgent bronchiolitis visit or scheduled visit at which additions to the bronchiolitis medications were made) during the 2 weeks after hospital discharge.

RESULTS

Among 1836 enrolled children with 2-week, follow-up data, the median age was 4 months and 60% were male. Overall, 48% had sole RSV infection, 8% had sole RV infection, and 13% had RSV/RV coinfection. Compared with children with sole RSV infection, and adjusting for 10 demographic and clinical characteristics and clustering of patients within hospitals, children with sole RV infection did not differ in their likelihood of relapse (odds ratio: 0.99; 95% confidence interval: 0.52-1.90; P = 0.98), whereas those with RSV/RV coinfection were more likely to have relapse (odds ratio: 1.54; 95% confidence interval: 1.03-2.30; P = 0.03).

CONCLUSIONS

In this prospective, multicenter, multiyear study of children hospitalized with bronchiolitis, we found that RSV/RV coinfection was independently associated with a higher likelihood of bronchiolitis relapse. Present data support the concept that the infectious etiology of severe bronchiolitis affects short-term outcomes.

Hospital length-of-stay is associated with rhinovirus etiology of bronchiolitis

OBJECTIVE

To determine whether hospital length-of-stay (LOS) for bronchiolitis is influenced by the causative virus: respiratory syncytial virus (RSV) or rhinovirus.

METHODS

This prospective study was carried out in 3 university hospitals in Finland during 2 consecutive winter seasons. We enrolled consecutive children <2 years of age hospitalized with an attending physician's diagnosis of bronchiolitis. All enrolled children were included in the primary analysis. A parallel analysis was also conducted using a stricter definition for bronchiolitis (age <12 months and no history of wheeze). Polymerase chain reaction was used to test the nasopharyngeal aspirate samples for multiple respiratory pathogens.

RESULTS

The median age of the 408 children was 8 months, 73% had no history of wheeze and their median hospital LOS was 2 days. 144 (35%) children had RSV only and 92 (23%) children rhinovirus only infections. Children with rhinovirus only had shorter duration of prehospital symptoms, higher disease severity score at entry and more often a history of wheezing (all P ≤ 0.001). Controlling for 7 demographic and clinical characteristics, those with rhinovirus only had shorter hospital LOS when compared with children with RSV only (adjusted odds ratio: 0.45; 95% confidence interval: 0.22-0.92; P = 0.03). The rhinovirus only finding was similar in the subset of 206 children with stricter diagnosis (adjusted odds ratio: 0.30; 0.06-1.49; P = 0.14).

CONCLUSIONS

Hospital LOS is associated with rhinovirus etiology of bronchiolitis. Our data call attention to the importance of both RSV and rhinovirus testing in clinical research.

Respiratory syncytial virus--a comprehensive review

Respiratory syncytial virus (RSV) is amongst the most important pathogenic infections of childhood and is associated with significant morbidity and mortality. Although there have been extensive studies of epidemiology, clinical manifestations, diagnostic techniques, animal models and the immunobiology of infection, there is not yet a convincing and safe vaccine available. The major histopathologic characteristics of RSV infection are acute bronchiolitis, mucosal and submucosal edema, and luminal occlusion by cellular debris of sloughed epithelial cells mixed with macrophages, strands of fibrin, and some mucin. There is a single RSV serotype with two major antigenic subgroups, A and B. Strains of both subtypes often co-circulate, but usually one subtype predominates. In temperate climates, RSV infections reflect a distinct seasonality with onset in late fall or early winter. It is believed that most children will experience at least one RSV infection by the age of 2 years. There are several key animal models of RSV. These include a model in mice and, more importantly, a bovine model; the latter reflects distinct similarity to the human disease. Importantly, the prevalence of asthma is significantly higher amongst children who are hospitalized with RSV in infancy or early childhood. However, there have been only limited investigations of candidate genes that have the potential to explain this increase in susceptibility. An atopic predisposition appears to predispose to subsequent development of asthma and it is likely that subsequent development of asthma is secondary to the pathogenic inflammatory response involving cytokines, chemokines and their cognate receptors. Numerous approaches to the development of RSV vaccines are being evaluated, as are the use of newer antiviral agents to mitigate disease. There is also significant attention being placed on the potential impact of co-infection and defining the natural history of RSV. Clearly, more research is required to define the relationships between RSV bronchiolitis, other viral induced inflammatory responses, and asthma.

Outpatient course and complications associated with home oxygen therapy for mild bronchiolitis

BACKGROUND

Home oxygen has been incorporated into the emergency department management of bronchiolitis in high-altitude settings. However, the outpatient course on oxygen therapy and factors associated with subsequent admission have not been fully defined.

METHODS

We conducted a retrospective cohort study in consecutive patients discharged on home oxygen from the pediatric emergency department at Denver Health Medical Center from 2003 to 2009. The integration of inpatient and outpatient care at our study institution allowed comprehensive assessment of follow-up rates, outpatient visits, time on oxygen, and subsequent admission. Admitted and nonadmitted patients were compared by using a χ(2) test and multivariable logistic regression.

RESULTS

We identified 234 unique visits with adequate follow-up for inclusion. The median age was 10 months (interquartile range [IQR]: 7-14 months). Eighty-three percent of patients were followed up within 24 hours and 94% within 48 hours. The median length of oxygen use was 6 days (IQR: 4-9 days), and the median number of associated encounters was 3 (range: 0-9; IQR: 2-3). Ninety-three percent of patients were on room air at 14 days. Twenty-two patients (9.4%) required subsequent admission. Fever at the initial visit (>38.0°C) was associated with admission (P < .02) but had a positive predictive value of 15.4%. Age, prematurity, respiratory rate, oxygen saturation, and history of previous bronchiolitis or wheeze were not associated with admission.

CONCLUSIONS

There is a significant outpatient burden associated with home oxygen use. Although fever was associated with admission, we were unable to identify predictors that could modify current protocols.

Infectious pathogens and bronchiolitis outcomes

Bronchiolitis is a common early childhood illness and an important cause of morbidity, it is the number one cause of hospitalization among US infants. Bronchiolitis is also an active area of research, and recent studies have advanced our understanding of this illness. Although it has long been the conventional wisdom that the infectious etiology of bronchiolitis does not affect outcomes, a growing number of studies have linked specific pathogens of bronchiolitis (e.g., rhinovirus) to short- and long-term outcomes, such as future risk of developing asthma. The authors review the advent of molecular diagnostic techniques that have demonstrated diverse pathogens in bronchiolitis, and they review recent studies on the complex link between infectious pathogens of bronchiolitis and the development of childhood asthma.

Impact of a bronchiolitis guideline on ED resource use and cost: a segmented time-series analysis

OBJECTIVE

Bronchiolitis is a major cause of infant morbidity and contributes to millions of dollars in health care costs. Care guidelines may cut costs by reducing unnecessary resource utilization. Through the implementation of a guideline, we sought to reduce unnecessary resource utilization and improve the value of care provided to infants with bronchiolitis in a pediatric emergency department (ED).

METHODS

We conducted an interrupted time series that examined ED visits of 2929 patients with bronchiolitis, aged 1 to 12 months old, seen between November 2007 and April 2013. Outcomes were proportion having a chest radiograph (CXR), respiratory syncytial virus (RSV) testing, albuterol or antibiotic administration, and the total cost of care. Balancing measures included admission rate, returns to the ED resulting in admission within 72 hours of discharge, and ED length of stay (LOS).

RESULTS

There were no significant preexisting trends in the outcomes. After guideline implementation, there was an absolute reduction of 23% in CXR (95% confidence interval [CI]: 11% to 34%), 11% in RSV testing (95% CI: 6% to 17%), 7% in albuterol use (95% CI: 0.2% to 13%), and 41 minutes in ED LOS (95% CI: 16 to 65 minutes). Mean cost per patient was reduced by $197 (95% CI: $136 to $259). Total cost savings was $196,409 (95% CI: $135,592 to $258,223) over the 2 bronchiolitis seasons after guideline implementation. There were no significant differences in antibiotic use, admission rates, or returns resulting in admission within 72 hours of discharge.

CONCLUSIONS

A bronchiolitis guideline was associated with reductions in CXR, RSV testing, albuterol use, ED LOS, and total costs in a pediatric ED.

Temporal trends in emergency department visits for bronchiolitis in the United States, 2006 to 2010

BACKGROUND

To examine temporal trends in emergency departments (EDs) visits for bronchiolitis among US children between 2006 and 2010.

METHODS

Serial, cross-sectional analysis of the Nationwide Emergency Department Sample, a nationally representative sample of ED patients. We used International Classification of Diseases, Ninth Revision, Clinical Modification code 466.1 to identify children <2 years of age with bronchiolitis. Primary outcome measures were rate of bronchiolitis ED visits, hospital admission rate and ED charges.

RESULTS

Between 2006 and 2010, weighted national discharge data included 1,435,110 ED visits with bronchiolitis. There was a modest increase in the rate of bronchiolitis ED visits, from 35.6 to 36.3 per 1000 person-years (2% increase; Ptrend = 0.008), due to increases in the ED visit rate among children from 12 months to 23 months (24% increase;Ptrend < 0.001). By contrast, there was a significant decline in the ED visit rate among infants (4% decrease; Ptrend < 0.001). Although unadjusted admission rate did not change between 2006 and 2010 (26% in both years), admission rate declined significantly after adjusting for potential patient- and ED-level confounders (adjusted odds ratio for comparison of 2010 with 2006, 0.84; 95% confidence interval: 0.76-0.93; P < 0.001). Nationwide ED charges for bronchiolitis increased from $337 million to $389 million (16% increase; Ptrend < 0.001), adjusted for inflation. This increase was driven by a rise in geometric mean of ED charges per case from $887 to $1059 (19% increase; Ptrend < 0.001).

CONCLUSIONS

Between 2006 and 2010, we found a divergent temporal trend in the rate of bronchiolitis ED visits by age group. Despite a significant increase in associated ED charges, ED-associated hospital admission rates for bronchiolitis significantly decreased over this same period.

Is the interpretation of rapid antigen testing for respiratory syncytial virus as simple as positive or negative?

OBJECTIVE

To measure the performance characteristics of an immunochromatographic rapid antigen test for respiratory syncytial virus (RSV) and determine how its interpretation should be contextualised in patients presenting to the emergency department (ED) with bronchiolitis.

DESIGN

Diagnostic accuracy study of a rapid RSV test.

SETTING

County hospital ED.

INTERVENTION

We took paired nasal samples from consecutively enrolled infants with bronchiolitis and tested them with a rapid immunochromatographic antigen test and reverse transcriptase PCR gold standard.

OUTCOME MEASURES

Sensitivity, specificity, the effect of point prevalence, clinical findings and overall context on predictive values. We used these to construct a graphical contextual model to show how the results of RSV antigen tests from infants presenting within 24 h should influence interpretation of subsequent antigen tests.

RESULTS

We analysed 607 patients. The sensitivity and specificity for immunochromatographic testing was 79.4% (95% CI 73.9% to 84.2%) and 67.1% (95% CI 61.9% to 72%) respectively. We found little evidence of spectrum bias. In our contextual model the best predictor of a positive RT-PCR test was a positive antigen test OR 5.47 (95% CI 3.65 to 8.18) and the number of other infants having positive tests within 24 h OR 1.48 (95% CI 1.26 to 1.72) per infant. Increasing numbers presenting to the ED with bronchiolitis in a given day increases the probability of RSV infection.

CONCLUSIONS

The RSV antigen test we examined had modest performance characteristics. The results of the antigen test should be interpreted in the context of the results of previous tests.

Trends in bronchiolitis hospitalizations in the United States, 2000-2009

OBJECTIVE

To examine temporal trend in the national incidence of bronchiolitis hospitalizations, use of mechanical ventilation, and hospital charges between 2000 and 2009.

METHODS

We performed a serial, cross-sectional analysis of a nationally representative sample of children hospitalized with bronchiolitis. The Kids Inpatient Database was used to identify children <2 years of age with bronchiolitis by International Classification of Diseases, Ninth Revision, Clinical Modification code 466.1. Primary outcome measures were incidence of bronchiolitis hospitalizations, mechanical ventilation (noninvasive or invasive) use, and hospital charges. Temporal trends were evaluated accounting for sampling weights.

RESULTS

The 4 separated years (2000, 2003, 2006, and 2009) of national discharge data included 544 828 weighted discharges with bronchiolitis. Between 2000 and 2009, the incidence of bronchiolitis hospitalization decreased from 17.9 to 14.9 per 1000 person-years among all US children aged <2 years (17% decrease; P(trend) < .001). By contrast, there was an increase in children with high-risk medical conditions (5.9%-7.9%; 34% increase; P(trend) < .001) and use of mechanical ventilation (1.9%-2.3%; 21% increase; P(trend) = .008). Nationwide hospital charges increased from $1.34 billion to $1.73 billion (30% increase; P(trend) < .001); this increase was driven by a rise in the geometric mean of hospital charges per case from $6380 to $8530 (34% increase; P(trend) < .001).

CONCLUSIONS

Between 2000 and 2009, we found a significant decline in bronchiolitis hospitalizations among US children. By contrast, use of mechanical ventilation and hospital charges for bronchiolitis significantly increased over this same period.