What is the clinical relevance of respiratory syncytial virus bronchiolitis?: findings from a multi-center, prospective study

Outcomes of viral coinfections in infants hospitalized for acute bronchiolitis

BACKGROUND AND OBJECTIVE

The clinical relevance of the detection of multiple respiratory viruses in acute bronchiolitis (AB) has not been established. Our goal was to evaluate the effect of viral coinfections on the progression and severity of AB.

METHODS

A retrospective observational study was conducted in a tertiary hospital in Spain from September 2012 to March 2020. Infants admitted for AB with at least one respiratory virus identified by molecular diagnostic techniques were included. A comparison was made between single-virus infections and viral coinfections. The evolution and severity of AB were determined based on the days of hospitalization and admission to the pediatric intensive care unit (PICU).

RESULTS

Four hundred forty-five patients were included (58.4% male). The median weight was 5.2 kg (IQR 4.2-6.5), and the median age was 2.5 months (IQR 1.4-4.6). A total of 105 patients (23.6%) were admitted to the PICU. Respiratory syncytial virus (RSV) was the most frequent etiological agent (77.1%). A single virus was detected in 270 patients (60.7%), and viral coinfections were detected in 175 (39.3%), of which 126 (28.3%) had two viruses and 49 (11%) had three or more viruses. Hospital length of stay (LOS) increased in proportion to the number of viruses detected, with a median of 6 days (IQR 4-8) for single infections, 7 days (IQR 4-9) for coinfections with two viruses and 8 days (IQR 5-11) for coinfections with ≥ 3 viruses (p = 0.003). The adjusted Cox regression model showed that the detection of ≥ 3 viruses was an independent risk factor for a longer hospital LOS (HR 0.568, 95% CI 0.410-0.785). No significant association was observed between viral coinfections and the need for PICU admission (OR 1.151; 95% CI 0.737-1.797).

CONCLUSIONS

Viral coinfections modified the natural history of AB, prolonging the hospital LOS in proportion to the number of viruses detected without increasing the need for admission to the PICU.

Impact of RSV test positivity, patient characteristics, and treatment characteristics on the cost of hospitalization for acute bronchiolitis in a French university medical center (2010-2015)

Background

In young children, respiratory syncytial virus (RSV)-related bronchiolitis is typically more severe than other respiratory tract infections, with a greater need for oxygen therapy and respiratory support. Few studies have compared the cost of hospitalization with regard to virological status. The objective of this study was to compare the costs of hospitalization for RSV-positive vs. RSV-negative bronchiolitis in a French university medical center between 2010 and 2015.

Methods

The cost models were compared using conventional goodness-of-fit criteria. Covariates included the characteristics of the patients, pre-existing respiratory and non-respiratory comorbidities, superinfections, medical care provided, and the length of stay.

Results

RSV was detected in 679 (58.3%) of the 1,164 hospital stays by children under 2 years with virological data. Oxygen therapy and respiratory support were twice as frequent for the RSV-positive cases. The median hospitalization cost was estimated at €3,248.4 (interquartile range: €2,572.1). The cost distribution was positively skewed with a variation coefficient (CV = standard deviation/mean) greater than one (mean = €4,212.9, standard deviation = €5,047, CV = 1.2). In univariate analyses, there was no significant cost difference between the RSV-positive and RSV-negative cases. In the best multivariate model, the significant positive effect of RSV positivity on cost waned after the introduction of medical care variables and the length of stay. The results were sensitive to the specification of the model.

Conclusions

It was impossible to firmly conclude that hospitalization costs were higher for the RSV-positive cases.

Clinical application of a lung sound analysis in infants with respiratory syncytial virus acute bronchiolitis

BACKGROUND

Objective investigation of the characteristics of acute bronchiolitis in infants is important for its diagnosis and treatment.

METHODS

Lung sound data of 50 patients diagnosed with respiratory syncytial virus (RSV) acute bronchiolitis (m:f = 29:21, median of age 7 months), 20 patients with RSV acute respiratory tract infections without acute bronchiolitis (m:f = 10:10, 5 months) and 38 age-matched control infants (m:f = 23:15, 8 months) were analyzed using a conventional method and compared. Furthermore, the relationships between lung sound parameters and clinical symptoms (clinical score, length of hospital stay and SpO2 level) in the bronchiolitis and the non-bronchiolitis patients were examined.

RESULTS

Results of lung sound analysis showed that the inspiratory sound power of patients with RSV respiratory tract infections was low and the expiratory sound power was high compared with those of the controls. When the patients with RSV respiratory tract infections were divided into the bronchiolitis and non-bronchiolitis groups, the expiratory/inspiratory ratio of the bronchiolitis patients was greater than that of the non-bronchiolitis patients. There was no difference in the clinical symptoms, clinical score and length of hospital stay between the bronchiolitis and non-bronchiolitis patients, except for the SpO2 level on admission.

CONCLUSION

Lung sound analysis confirmed that patients with RSV acute bronchiolitis present with marked airway narrowing. Considering these results as a characteristic of acute bronchiolitis, it would be meaningful to reflect it in the improvement of diagnosis, treatment and subsequent management.

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.

Respiratory Complications in Children Hospitalized with Respiratory Syncytial Virus Infection

The goal of this study was to define the prevalence of respiratory complications, other than bronchiolitis, such as pneumonia, acute otitis media, and conjunctivitis in children treated in a hospital due to respiratory syncytial virus (RSV) infection, with reference to the plausible risk factors. The study included 111 children, aged up to 22 months (median 3 months). Complications were observed in 68 (61%) children, with 32 (29%) children presenting more than one. The most frequent complication was acute otitis media in 53 (48%), pneumonia in 37 (33%), and conjunctivitis in 12 (11%) out of the 111 children. Children with complications were older than those without complications and had fever that lasted for a significantly longer time, both before and during hospitalization, and the fever was stronger. They also presented a significantly lower breathing rate at admission. The age over 3 months was a single risk factor associated with the development of otitis media (OR = 9.8, 95%CI: 3.6-26.7) and pneumonia (OR = 2.8, 95%CI: 1.1-7.3). Other factors such as prematurity, birth weight below 2500 g, exposure to tobacco smoke during pregnancy, and the cessation of breastfeeding below age 6 months were statistically irrelevant to this end. We conclude that complications are very frequent in hospitalized children with RSV infection and their risk increases with the infant age.

Ten years of severe respiratory syncytial virus infections in a tertiary paediatric intensive care unit

AIM

To describe the epidemiology and treatment of respiratory syncytial virus (RSV) infection in a tertiary paediatric intensive care unit (PICU), including the clinical presentations, comorbidities, respiratory support required, costs and outcomes.

METHODS

This study was an analysis of a database for all children with RSV infections admitted to the PICU in Melbourne between 2005 and 2015.

RESULTS

A total of 604 episodes of community-acquired RSV infections were analysed, and the median age of children was 4 months (interquartile range 2-14 months); 94% of cases had lower respiratory tract infection, principally bronchiolitis, and 8.9% presented with extrapulmonary features. Respiratory support included humidified high-flow nasal cannula oxygen therapy (76% of patients since its introduction in 2011), non-invasive ventilation (41%) and intubation and mechanical ventilation (32%). Almost half (n = 270; 45%) had one or more pre-existing comorbid condition. Risk factors for intubation and mechanical ventilation were presence of comorbidities (odds ratio 1.97; confidence interval 1.39-2.79, P < 0.001) and transfer from an external hospital (odds ratio 1.82; confidence interval 1.58-2.57, P < 0.001). Of the children without pre-existing comorbidities, 25% required intubation and mechanical ventilation. Following the introduction of humidified high-flow nasal cannula oxygen therapy, the number of annual PICU admissions for RSV infection doubled; however, the number of children requiring intubation remained unchanged. The median length of intensive care unit stay was 3.7 days and further hospital stay was 3.6 days, and the average cost per case was approximately AU$20000.

CONCLUSIONS

RSV infection carries a high burden in PICU, in bed-days and cost. Chronic comorbidities and transfer from a peripheral hospital were associated with a higher rate of need for mechanical ventilation.

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.

Should we use Palivizumab immunoprophylaxis for infants against respiratory syncytial virus? - a cost-utility analysis

BACKGROUND

Passive immunization against RSV (Respiratory Syncytial Virus) is given in most western countries (including Israel) to infants of high risk groups such as premature babies, and infants with Congenital Heart Disease or Congenital Lung Disease. However, immunoprophylaxis costs are extremely high ($2800-$4200 per infant). Using cost-utility analysis criteria, we evaluate whether it is justified to expand, continue or restrict nationwide immunoprophylaxis using palivizumab of high risk infants against RSV.

METHODS

Epidemiological, demographic, health service utilisation and economic data were integrated from primary (National Hospitalization Data, etc.) and secondary data sources (ie: from published articles) into a spread-sheet to calculate the cost per averted disability-adjusted life year (DALY) of vaccinating various infant risk groups. Costs of intervention included antibody plus administration costs. Treatment savings and DALYs averted were estimated from applying vaccine efficacy data to relative risks of being hospitalised and treated for RSV, including possible long-term sequelae like asthma and wheezing.

RESULTS

For all the groups RSV immunoprophylaxis is clearly not cost effective as its cost per averted DALY exceeds the $105,986 guideline representing thrice the per capita Gross Domestic Product. Vaccine price would have to fall by 48.1% in order to justify vaccinating Congenital Heart Disease or Congenital Lung Disease risk groups respectively on pure cost-effectiveness grounds. For premature babies of < 29 weeks, 29-32 and 33-36 weeks gestation, decreases of 36.8%, 54.5% and 83.3% respectively in vaccine price are required.

CONCLUSIONS

Based solely on cost-utility analysis, at current price levels it is difficult to justify the current indications for passive vaccination with Palivizumab against RSV. However, if the manufacturers would reduce the price by 54.5% then it would be cost-effective to vaccinate the Congenital Heart Disease or Congenital Lung Disease risk groups as well as premature babies born before the 33rd week of gestation.

Increased severity of respiratory syncytial virus airway infection due to passive smoke exposure

OBJECTIVE

Aim of this study was to analyze whether children with objectively measured second-hand cigarette smoke (SHS) exposure suffer from a more severe course of disease when hospitalized with lower respiratory tract infection (LRTI) due to respiratory syncytial virus (RSV).

METHODS

This prospective study was conducted at the Department of Pediatrics, Wilhelminen-Hospital, Vienna, Austria in children aged below 1 year without a history of preceding lung disease and with acute symptoms of LRTI and a positive nasopharyngeal swab for RSV. On admission, urinary cotinine was measured as a marker of recent SHS and clinical severity of LRTI was assessed by oxygen saturation SpO₂ and the "admission clinical severity score" (CSSA). Parents/caregivers were asked to complete a customized questionnaire assessing risks for SHS and demographic characteristics.

RESULTS

After inclusion of 217 patients, data of 185 patients with a mean (SD) age of 106 days (80) were analyzed. Twenty-five patients (13.5%) were "cotinine-positive" (COT+) defined as a urinary cotinine level of ≥7 μg/L. SpO₂ on admission was significantly lower in children recently exposed to SHS defined objectively by COT+ (94.8%  ±2.0) in urine on admission compared to children not recently exposed (COT-) (96.8% ±3.0; P < 0.01). Disease severity, assessed via mean clinical severity score on admission (CSSA) for COT+ and COT- was 2.56 and 1.71, respectively (P = 0.03).

CONCLUSIONS

Recent exposure to SHS was associated with lower O₂ saturation and higher clinical severity score, measured by urine cotinine levels in children hospitalized for RSV infection under 1 year of age.

Bordetella Pertussis Infection in Hospitalized Infants with Acute Bronchiolitis

OBJECTIVE

To assess the frequency of B. pertussis infection among young infants hospitalized with acute bronchiolitis and to determine whether B. pertussis infection affects the clinical course of acute bronchiolitis.

METHODS

A total of 172 infants <6 months of age hospitalized with acute bronchiolitis were tested for B. pertussis and respiratory viruses with real-time PCR. Cases were divided into 2 groups according to B. pertussis positive or negative. Clinical parameters, clinical severity scores and laboratory characteristics of the pertussis-positive and pertussis-negative cases were compared.

RESULTS

Bordetella pertussis infection was detected in 44 (25.6%) of the 172 infants hospitalized for acute bronchiolitis, and as co-infection with respiratory viral agents in 27 (61.4%) infants. Of the 44 pertussis-positive infants, only 17 (38.6%) experienced a paroxysmal cough, 13 (29.5%) had whooping and 15 (34.1%) had post-tussive vomiting. There was no significant difference between pertussis-positive and pertussis-negative infants according to Wang clinical score at admission (4.9 ± 1.5 vs. 5.2 ± 2.5; p = 0.689). The overall disease severity score was also similar between the two groups (6.5 ± 1.4 vs. 6.9 ± 1.6; p = 0.095).

CONCLUSIONS

Bordetella pertussis infection is common in young infants hospitalized for acute bronchiolitis, mostly as co-infection with respiratory viruses. The clinical features of pertussis in the infants are not characteristic. Viral bronchiolitis and pertussis cases could not be differentiated by clinical findings. Co-infection with pertussis did not affect the clinical outcome in infants hospitalized with acute bronchiolitis.

The modified respiratory index score (RIS) guides resource allocation in acute bronchiolitis

BACKGROUND AND OBJECTIVE

Bronchiolitis is a common disease in early childhood with increasing healthcare utilization. We aim to study how well a simple and improved respiratory score (the modified Respiratory Index Score [RIS]) would perform when predicting for a warranted admission.

METHODS

This is an observational prospective study, from June 2015 to December 2015 in a paediatric emergency department (ED) of a large tertiary hospital in Singapore. We included children aged less than 2 years old, presenting with typical symptoms and signs of bronchiolitis but excluded children with four or more previous wheezes, a gestation of <35 weeks, and known cardiopulmonary disease. We also performed a sensitivity analysis for children presenting with their first wheeze. We defined a warranted admission as a composite of: The need for airway intervention, intravenous hydration, and a hospital stay of 2 days or more.

RESULTS

Among 1,818 patients, the median age was 10.8 months (IQR 7.2-15.9). The median modified RIS score was 4.0 (IQR 3.0-5.0). A total of 19 (1.0%) children required respiratory support, 101 (5.6%) received intravenous hydration, and 571 (31.4%) required a hospital stay of 2 days or more. After adjusting for age and duration of illness, a modified RIS score of >4 predicted significantly for a warranted admission (adjusted Odds Ratio: 3.28, 95% confidence interval: 2.62-4.12). The association remained significant among children presenting with their first wheeze.

CONCLUSIONS

This simple respiratory tool predicts for the need for respiratory support, intravenous hydration, and a significant hospital stay of 2 days or more. Pediatr Pulmonol. 2017; 52:954-961. © 2017 Wiley Periodicals, Inc.

Influenza and other respiratory viruses: standardizing disease severity in surveillance and clinical trials

INTRODUCTION

Influenza-Like Illness is a leading cause of hospitalization in children. Disease burden due to influenza and other respiratory viral infections is reported on a population level, but clinical scores measuring individual changes in disease severity are urgently needed. Areas covered: We present a composite clinical score allowing individual patient data analyses of disease severity based on systematic literature review and WHO-criteria for uncomplicated and complicated disease. The 22-item ViVI Disease Severity Score showed a normal distribution in a pediatric cohort of 6073 children aged 0-18 years (mean age 3.13; S.D. 3.89; range: 0 to 18.79). Expert commentary: The ViVI Score was correlated with risk of antibiotic use as well as need for hospitalization and intensive care. The ViVI Score was used to track children with influenza, respiratory syncytial virus, human metapneumovirus, human rhinovirus, and adenovirus infections and is fully compliant with regulatory data standards. The ViVI Disease Severity Score mobile application allows physicians to measure disease severity at the point-of care thereby taking clinical trials to the next level.

Bronchiolitis in young infants: is it a risk factor for recurrent wheezing in childhood?

BACKGROUND

Acute bronchiolitis in infancy is considered a risk factor for recurrent wheezing episodes in childhood. The present study assessed prevalence, clinical manifestations and risk factors for recurrent wheezing events during the first 3 years of life and persistent wheezing events beyond this age in children hospitalized as young infants with acute bronchiolitis.

METHODS

Two groups of children aged 6 years were included. The study group comprised 150 children with a history of hospitalization for bronchiolitis, with the first event at <6 months of age. The control group comprised 66 age- and sex-matched children with no history of bronchiolitis before 6 months of age. Children in both groups had been followed until 6 years of age by their pediatricians; data were obtained retrospectively by reviewing ambulatory records during children's visits in pediatricians' clinics. The data included epidemiological parameters, prevalence, age at onset, number of and treatments given for episodes of wheezing events prior to 6 years of age, pathogens detected, and severity of acute bronchiolitis in the study group.

RESULTS

Overall, 58% and 27% of children in the study and control groups, respectively (P=0.001) had recurrent wheezing episodes prior to the age of 3 years. Children in the study group had earlier onset of recurrent wheezing, had more episodes of wheezing, and required more bronchodilator and systemic steroids treatments compared to the control group.

CONCLUSION

Hospitalization within the first six months of life for acute bronchiolitis is an independent risk factor for recurrent wheezing episodes during the first 3 years of life.

Etiology and clinical features of viral bronchiolitis in infancy

BACKGROUND

Bronchiolitis is a common lower respiratory tract infection in infancy. The aim of this review is to present the clinical profile of viral bronchiolitis, the different culprit viruses and the disease severity in relation to the viral etiology.

DATA SOURCES

Databases including PubMed and Google Scholar were searched for articles about the clinical features of bronchiolitis and its viral etiology. The most relevant articles to the scope of this review were analyzed.

RESULTS

Currently there are two main definitions for bronchiolitis which are not identical, the European definition and the American one. The most common viral pathogen that causes bronchiolitis is respiratory syncytial virus which was identified in 1955; now many other viruses have been implicated in the etiology of bronchiolitis such as rhinovirus, adenovirus, metapneumovirus, and bocavirus. Several studies have attempted to investigate the correlation of bronchiolitis severity with the type of detected virus or viruses. However, the results were not consitent.

CONCLUSIONS

For the time being, the diagnosis of bronchiolitis remains clinical. The isolation of the responsible respiratory pathogens does not seem to confer to the prognosis of the disease severity.

Risk factors for adverse outcomes of Indigenous infants hospitalized with bronchiolitis

BACKGROUND

Hospitalized bronchiolitis imposes a significant burden among infants, particularly among Indigenous children. Traditional or known risk factors for severe disease are well described, but there are limited data on risks for prolonged hospitalization and persistent symptoms. Our aims were to determine factors (clinical and microbiological) associated with (i) prolonged length of stay (LOS); (ii) persistent respiratory symptoms at 3 weeks; (iii) bronchiectasis up to ∼24 months post-hospitalisation; and (iv) risk of respiratory readmissions within 6 months.

METHODS

Indigenous infants hospitalized with bronchiolitis were enrolled at Royal Darwin Hospital between 2008 and 2013. Standardized forms were used to record clinical data. A nasopharyngeal swab was collected at enrolment to identify respiratory viruses and bacteria.

RESULTS

The median age of 232 infants was 5 months (interquartile range 3-9); 65% male. On multivariate regression, our 12 point severity score (including accessory muscle use) was the only factor associated with prolonged LOS but the effect was modest (+3.0 hr per point, 95%CI: 0.7, 5.1, P = 0.01). Presence of cough at 3 weeks increased the odds of bronchiectasis (OR 3.0, 95%CI: 1.1, 7.0, P = 0.03). Factors associated with respiratory readmissions were: previous respiratory hospitalization (OR 2.3, 95%CI: 1.0, 5.4, P = 0.05) and household smoke (OR 2.6, 95%CI: 1.0, 6.3, P = 0.04).

CONCLUSION

Increased severity score is associated with prolonged LOS in Indigenous children hospitalized with bronchiolitis. As persistent symptoms at 3 weeks post-hospitalization are associated with future diagnosis of bronchiectasis, optimising clinical care beyond hospitalization is needed to improve long-term respiratory outcomes for infants at risk of respiratory disease. Pediatr Pulmonol. 2016;51:613-623. © 2015 Wiley Periodicals, Inc.

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

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

Virus Type and Genomic Load in Acute Bronchiolitis: Severity and Treatment Response With Inhaled Adrenaline

Background. Acute bronchiolitis frequently causes infant hospitalization. Studies on different viruses or viral genomic load and disease severity or treatment effect have had conflicting results. We aimed to investigate whether the presence or concentration of individual or multiple viruses were associated with disease severity in acute bronchiolitis and to evaluate whether detected viruses modified the response to inhaled racemic adrenaline.

Methods. Nasopharyngeal aspirates were collected from 363 infants with acute bronchiolitis in a randomized, controlled trial that compared inhaled racemic adrenaline versus saline. Virus genome was identified and quantified by polymerase chain reaction analyses. Severity was assessed on the basis of the length of stay and the use of supportive care.

Results. Respiratory syncytial virus (83%) and human rhinovirus (34%) were most commonly detected. Seven other viruses were present in 8%–15% of the patients. Two or more viruses (maximum, 7) were detected in 61% of the infants. Virus type or coinfection was not associated with disease severity. A high genomic load of respiratory syncytial virus was associated with a longer length of stay and with an increased frequency of oxygen and ventilatory support use. Treatment effect of inhaled adrenaline was not modified by virus type, load or coinfection.

Discussion. In infants hospitalized with acute bronchiolitis, disease severity was not associated with specific viruses or the total number of viruses detected. A high RSV genomic load was associated with more-severe disease.

Clinical Trials Registration. NCT00817466 and EudraCT 2009-012667-34.

Nasopharyngeal bacterial burden and antibiotics: Influence on inflammatory markers and disease severity in infants with respiratory syncytial virus bronchiolitis

OBJECTIVES

Animal studies suggest that RSV increases nasopharyngeal (NP) bacterial colonization facilitating bacterial infections. We investigated the influence of antibiotic treatment and colonization with potentially pathogenic bacteria on inflammatory markers and disease severity in RSV-infected in infants.

METHODS

Healthy young infants hospitalized with RSV bronchiolitis (n = 136) and age-matched healthy controls (n = 23) were enrolled and NP samples cultured for potentially pathogenic bacteria including: Gram-positive bacteria (GPB): Staphylococcus aureus, Streptococcus pneumoniae, β-hemolytic Streptococcus; and Gram-negative bacteria (GNB): Moraxella catarrhalis and Haemophilus influenzae. Clinical parameters and plasma IL-8, IL-6 and TNF-α concentrations were compared according to the bacterial class and antibiotic treatment.

RESULTS

Antibiotic treatment decreased by 10-fold NP bacterial recovery. Eighty-one percent of RSV infants who did not receive antibiotics before sample collection were colonized with pathogenic bacteria. Overall, GNB were identified in 21% of patients versus 4% of controls who were mostly colonized with GPB. Additionally, in RSV patients NP white blood cell counts (p = 0.026), and blood neutrophils (p = 0.02) were higher in those colonized with potentially pathogenic bacteria versus respiratory flora. RSV patients colonized with GNB had higher plasma IL-8 (p = 0.01) and IL-6 (p < 0.01) concentrations than controls, and required longer duration of oxygen (p = 0.049).

CONCLUSIONS

Infants with RSV bronchiolitis colonized with potentially pathogenic bacteria had increased numbers of mucosal and systemic inflammatory cells. Specifically, colonization with GNB was associated with higher concentrations of proinflammatory cytokines and a trend towards increased disease severity.

Virologic testing in bronchiolitis: does it change management decisions and predict outcomes?

The aim of this study was to evaluate the clinical, therapeutic, laboratory, and radiological differences between respiratory syncytial virus (RSV) and non-RSV bronchiolitis in order to assess if the prior knowledge of viral etiology changed management decisions and would be able to predict outcomes. Medical charts of children <1 year admitted to the emergency department with bronchiolitis during two RSV seasons (2010-2012) were reviewed. We analyzed 221 episodes of bronchiolitis. The percentage of exams performed (95 % confidence interval (CI) 0.74-2.52), abnormal laboratory and radiological findings (95 % CI 0.53-16.89) did not differ between groups. RSV bronchiolitis had a more severe clinical course. However, virologic testing for RSV had low specificity in identifying at-risk patients for hospitalization, longer hospital length of stay, and need of oxygen therapy and nasogastric tube (44, 40, 42, and 35 %, respectively), and while statistically significant, the positive likelihood ratios were only slightly greater than 1.

CONCLUSION

Although RSV bronchiolitis has a more severe clinical course, virologic testing does not help in management decisions, and at an individual level, as a performance test, it seems insufficient to precisely predict outcomes.

Social, economic, and health impact of the respiratory syncytial virus: a systematic search

BACKGROUND

Bronchiolitis caused by the respiratory syncytial virus (RSV) and its related complications are common in infants born prematurely, with severe congenital heart disease, or bronchopulmonary dysplasia, as well as in immunosuppressed infants. There is a rich literature on the different aspects of RSV infection with a focus, for the most part, on specific risk populations. However, there is a need for a systematic global analysis of the impact of RSV infection in terms of use of resources and health impact on both children and adults. With this aim, we performed a systematic search of scientific evidence on the social, economic, and health impact of RSV infection.

METHODS

A systematic search of the following databases was performed: MEDLINE, EMBASE, Spanish Medical Index, MEDES-MEDicina in Spanish, Cochrane Plus Library, and Google without time limits. We selected 421 abstracts based on the 6,598 articles identified. From these abstracts, 4 RSV experts selected the most relevant articles. They selected 65 articles. After reading the full articles, 23 of their references were also selected. Finally, one more article found through a literature information alert system was included.

RESULTS

The information collected was summarized and organized into the following topics: 1. Impact on health (infections and respiratory complications, mid- to long-term lung function decline, recurrent wheezing, asthma, other complications such as otitis and rhino-conjunctivitis, and mortality; 2. Impact on resources (visits to primary care and specialists offices, emergency room visits, hospital admissions, ICU admissions, diagnostic tests, and treatments); 3. Impact on costs (direct and indirect costs); 4. Impact on quality of life; and 5. Strategies to reduce the impact (interventions on social and hygienic factors and prophylactic treatments).

CONCLUSIONS

We concluded that 1. The health impact of RSV infection is relevant and goes beyond the acute episode phase; 2. The health impact of RSV infection on children is much better documented than the impact on adults; 3. Further research is needed on mid- and long-term impact of RSV infection on the adult population, especially those at high-risk; 4. There is a need for interventions aimed at reducing the impact of RSV infection by targeting health education, information, and prophylaxis in high-risk populations.

Bordetella pertussis infection attenuates clinical course of acute bronchiolitis

BACKGROUND

Bordetella pertussis (BP) was detected in hospitalized children with various lower respiratory tract infections. The aim of this study was to assess clinical characteristics of BP infection, and its effect on disease severity in young children hospitalized with acute bronchiolitis.

METHODS

Included were previously healthy children ≤2 years of age who were hospitalized with acute bronchiolitis. In each patient, BP and 10 other possible pathogens were tested. Subjects were divided into 2 matched groups: cases in whom BP was detected, and controls in whom BP was not detected (ratio 1:4, respectively). Clinical parameters and clinical severity scores on admission and during hospitalization were compared between the 2 groups.

RESULTS

Overall, BP was detected in 24 of 309 (7.7 %) of children, 16 (67%) also with respiratory syncytial virus and 2 (8%) with BP as the sole pathogen. Cases compared with controls had lower rates of feeding problems before admission (30.5%, and 53.1%, respectively, P = 0.007). Upon admission, cases had a significantly lower percentage of combined "moderate" and "severe" clinical severity scores (13% versus 41.6% P = 0.001). The mean clinical severity score during hospitalization was also significantly lower in cases than controls (5.3 ± 1.6 versus 5.8 ± 1.5, respectively, P = 0.03).

CONCLUSIONS

BP was detected in young children hospitalized with acute bronchiolitis mostly as a coagent. Children with BP infection had a lower disease severity both on admission and during hospitalization than those in whom BP was not detected.