Bronchiolitis In Young Infants Research Articles

Genome-wide study of globally distributed respiratory syncytial virus (RSV) strains implicates diversification utilizing phylodynamics and mutational analysis

Respiratory syncytial virus (RSV) is a common respiratory pathogen that causes mild cold-like symptoms and severe lower respiratory tract infections, causing hospitalizations in children, the elderly and immunocompromised individuals. Due to genetic variability, this virus causes life-threatening pneumonia and bronchiolitis in young infants. Thus, we examined 3600 whole genome sequences submitted to GISAID by 31 December 2022 to examine the genetic variability of RSV. While RSVA and RSVB coexist throughout RSV seasons, RSVA is more prevalent, fatal, and epidemic-prone in several countries, including the United States, the United Kingdom, Australia, and China. Additionally, the virus's attachment glycoprotein and fusion protein were highly mutated, with RSVA having higher Shannon entropy than RSVB. The genetic makeup of these viruses contributes significantly to their prevalence and epidemic potential. Several strain-specific SNPs co-occurred with specific haplotypes of RSVA and RSVB, followed by different haplotypes of the viruses. RSVA and RSVB have the highest linkage probability at loci T12844A/T3483C and G13959T/C2198T, respectively. The results indicate that specific haplotypes and SNPs may significantly affect their spread. Overall, this analysis presents a promising strategy for tracking the evolving epidemic situation and genetic variants of RSV, which could aid in developing effective control, prophylactic, and treatment strategies.

Factors associated with mild bronchiolitis in young infants.

Bronchiolitis within the first 3 months of life is a risk factor for more severe illness. We aimed to identify characteristics associated with mild bronchiolitis in infants ≤90 days old presenting to the emergency department (ED). We conducted a secondary analysis of infants ≤90 days old with clinically diagnosed bronchiolitis using data from the 25th Multicenter Airway Research Collaboration prospective cohort study. We excluded infants with direct intensive care unit admissions. Mild bronchiolitis was defined as (1) sent home after the index ED visit and did not have a return ED visit or had a return ED visit without hospitalization, or (2) were hospitalized from the index ED visit to the inpatient floor for<24hours. Multivariable logistic regression, adjusting for potential clustering by hospital site, was used to identify factors associated with mild bronchiolitis. Of 373 infants aged ≤90 days, 333 were eligible for analysis. Of these, 155 (47%) infants had mild bronchiolitis, and none required mechanical ventilation. Adjusting for infant characteristics, clinical factors associated with mild bronchiolitis included older age (61-90 days vs 0-60 days) (odds ratio [OR] 2.72, 95% confidence interval [CI] 1.52-4.87), adequate oral intake (OR 4.48, 95% CI 2.08-9.66), and lowest ED oxygen saturation ≥94% (OR 3.12, 95% CI 1.55-6.30). Among infants aged ≤90 days presenting to the ED with bronchiolitis, about half had mild bronchiolitis. Mild illness was associated with older age (61-90 days), adequate oral intake, and oxygen saturation ≥94%. These predictors may help in the development of strategies to limit unnecessary hospitalization in young infants with bronchiolitis.

Immunological and Inflammatory Biomarkers of Susceptibility and Severity in Adult Respiratory Syncytial Virus Infections.

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis in young infants. However, it is also a significant pathogen in older adults. Validated biomarkers of RSV disease severity would benefit diagnostics, treatment decisions, and prophylactic interventions. This review summarizes knowledge of biomarkers for RSV disease in adults. A literature review was performed using Ovid Medline, Embase, Global health, Scopus, and Web of Science for articles published 1946-October 2016. Nine articles were identified plus 9 from other sources. From observational studies of natural infection and challenge studies in volunteers, biomarkers of RSV susceptibility or disease severity in adults were: (1) lower anti-RSV neutralizing antibodies, where neutralizing antibody (and local IgA) may be a correlate of susceptibility/severity; (2) RSV-specific CD8+ T cells in bronchoalveolar lavage fluid preinfection (subjects with higher levels had less severe illness); and (3) elevated interleukin-6 (IL-6), IL-8, and myeloperoxidase levels in the airway are indicative of severe infection. Factors determining susceptibility to and severity of RSV disease in adults have not been well defined. Respiratory mucosal antibodies and CD8+ T cells appear to contribute to preventing infection and modulation of disease severity. Studies of RSV pathogenesis in at-risk populations are needed.

Monoclonal Antibody Treatment of RSV Bronchiolitis in Young Infants: A Randomized Trial.

Monoclonal antibody to respiratory syncytial virus (RSV; palivizumab) is recommend for prophylaxis of high-risk infants during bronchiolitis seasons but not for RSV bronchiolitis treatment. Our aim was to determine if palivizumab would be helpful in young infants with acute RSV bronchiolitis. Eligible infants ≤3 months old presenting to the pediatric emergency service with RSV-positive bronchiolitis requiring inpatient admission underwent double-blind random assignment to single-dose intravenous palivizumab (15 mg/kg) or placebo. The primary efficacy outcome was the need for inpatient readmission in the 3 weeks after discharge. Secondary outcomes were time to readiness for hospital discharge, need for PICU on the initial admission, and need for revisit not requiring readmission for the same illness during 3-week follow-up. A total of 420 infants (median age 49 days) diagnosed with RSV bronchiolitis were randomly assigned; 417 received treatment, and 413 completed follow-up. Readmission during follow-up was needed for 23 (11%) patients on palivizumab and 19 (9.3%) patients in the placebo group (difference 1.8%; 95% confidence interval -4.4% to 7.7%; P = .51). Geometric mean time to readiness for discharge was 29.5 hours for the palivizumab group and 30.2 hours for the placebo group (ratio 0.98; 95% confidence interval 0.81 to 1.20). No safety issues were reported. Intravenous palivizumab did not appear to help or harm young infants with acute RSV-positive bronchiolitis.

Welche Atemunterstützung bei akuter viraler Bronchiolitis im Säuglingsalter?

Milési C et al. High flow nasal cannula (HFNC) versus nasal continuous positive airway pressure (nCPAP) for the initial respiratory management of acute viral bronchiolitis in young infants: a multicenter randomized controlled trial (TRAMONTANE study). Intensive Care Med 2017; 43: 209 – 216

High flow nasal cannula (HFNC) versus nasal continuous positive airway pressure (nCPAP) for the initial respiratory management of acute viral bronchiolitis in young infants: a multicenter randomized controlled trial (TRAMONTANE study).

Nasal continuous positive airway pressure (nCPAP) is currently the gold standard for respiratory support for moderate to severe acute viral bronchiolitis (AVB). Although oxygen delivery via high flow nasal cannula (HFNC) is increasingly used, evidence of its efficacy and safety is lacking in infants. A randomized controlled trial was performed in five pediatric intensive care units (PICUs) to compare 7cmH2O nCPAP with 2L/kg/min oxygen therapy administered with HFNC in infants up to 6months old with moderate to severe AVB. The primary endpoint was the percentage of failure within 24h of randomization using prespecified criteria. To satisfy noninferiority, the failure rate of HFNC had to lie within 15% of the failure rate of nCPAP. Secondary outcomes included success rate after crossover, intubation rate, length of stay, and serious adverse events. From November 2014 to March 2015, 142 infants were included and equally distributed into groups. The risk difference of -19% (95% CI -35 to -3%) did not allow the conclusion of HFNC noninferiority (p=0.707). Superiority analysis suggested a relative risk of success 1.63 (95% CI 1.02-2.63) higher with nCPAP. The success rate with the alternative respiratory support, intubation rate, durations of noninvasive and invasive ventilation, skin lesions, and length of PICU stay were comparable between groups. No patient had air leak syndrome or died. In young infants with moderate to severe AVB, initial management with HFNC did not have a failure rate similar to that of nCPAP. This clinical trial was recorded in the National Library of Medicine registry (NCT 02457013).

Evaluation of Serum 25-Hydroxy Vitamin D Levels in Children with Acute Bronchiolitis

Background: According to some reports, 25-hydroxy vitamin D (25 (OH) D) deficiency leads to respiratory diseases. Given the high prevalence of acute bronchiolitis in young infants, the assessment of 25 (OH) D status is very important for this disease. Objectives: This study was conducted to determine the relationship between the serum levels of 25 (OH) D and acute bronchiolitis in young infants. Methods: In the present study, 57 patients with acute bronchiolitis (case control) were compared with 57 healthy children (control group) in terms of 25 (OH) D serum levels. The serum levels of 25 (OH) D were measured using the ELISA method. The results were analyzed and compared between the two groups. Results: The mean and standard deviation of 25 (OH) D serum levels were 26 ± 9.5 and 23.3 ± 8.3 ng/mL in the case and control groups, respectively. No significant difference was observed between the two groups in terms of 25 (OH) D serum levels (P = 0.11). Conclusions: This study showed that there is no significant difference between children with acute bronchiolitis and normal children in terms of serum 25 (OH) D levels. It therefore seems that 25 (OH) D does not play any role in the pathogenesis of acute bronchiolitis. Further studies in this area are recommended.

Neutrophil but not eosinophil inflammation is related to the severity of a first acute epidemic bronchiolitis in young infants

Acute bronchiolitis is the main cause of emergency visits and hospitalizations in infants. Recent data suggest that neutrophil- and eosinophil-mediated inflammations were part of bronchiolitis pathophysiology. Apart from the defined risk factors, few was known on the underlying pathophysiology, which might point out the differences observed in the severity of the disease. The aim of this study was to assess whether the clinical severity of acute epidemic bronchiolitis in young infants might be related to a specific underlying inflammatory process. Total and differential cell counts, IL-8, eotaxin, eosinophil cationic protein (ECP) and albumin levels were assessed at the time of admission in bronchial secretions from 37 infants (median age 17 wk) with acute bronchiolitis. Outcome severity variables were: hypoxemia, Silverman score, tachypnea, feeding alteration, and duration of hospitalization. Neutrophils predominated, and eosinophils were present in 54% of the infants. IL-8 levels strongly correlated with ECP and albumin levels. Albumin levels were correlated with ECP and eotaxin levels. IL-8 levels were higher in infants with hypoxemia and inversely related with SaO(2) levels. IL-8 and albumin levels significantly rose with respiratory rate, and Silverman score. IL-8, albumin and ECP levels were significantly higher in infants hospitalized >/=7 days. Furthermore, IL-8 levels were correlated with the duration of hospitalization. Neither cell counts nor eotaxin levels were related to the severity criteria studied. This study suggests that IL-8-associated airway inflammation significantly contributed to the severity of acute epidemic bronchiolitis.

The Severity of Respiratory Syncytial Virus Bronchiolitis in Young Infants in the United Arab Emirates

Respiratory syncytial virus (RSV) respiratory infections are very common during infancy and account for the majority of hospitalizations during the fall and winter seasons. Patients vary in the severity of their illnesses, with most hospitalized patients needing oxygen and intravenous fluids. The objective of this study was to assess in hospitalized patients the severity of the disease in relation to age. We compared children who were <90 days old with children who were >90 days old for the duration of oxygen therapy, maximum oxygen concentration used, duration of stay and duration of intravenous fluids. We conducted a retrospective case review of national children <2 years admitted to the pediatric ward at Sheikh Khalifa Medical City with RSV proven bronchiolitis/pneumonia over a 3-month period from 1 September to 30 November 2001. Morbidity for group 1 (birth-90 days) and group 2 (91 days-2 years) was compared by the Mann-Whitney U-test using duration of oxygen therapy, maximum oxygen concentration used, duration of stay and duration of intravenous fluids. Multiple regression for duration of oxygen therapy was tested using the following risk factors as predictors: age group (1 or 2), previous ventilation, bronchopulmonary dysplasia (BPD) and prematurity. A total of 89 patients were admitted during this period. The mean age (SD) of group 1 (n = 28) and group 2 (n = 61) was 46.35 (25.57) days and 275.67 (156.79) days, respectively. The only statistically significant difference using the Mann-Whitney U-test was detected for duration of oxygen between the groups (p = 0.002). Using multiple regression, only age group acted as a predictor for duration of oxygen therapy (p < 0.001). This implies that the youngest children, group 1, are at a risk for prolonged oxygen therapy. Four patients from group 1 were admitted to the intensive care unit, of which two received ventilatory support. RSV respiratory infections affect infants <3 months old in a more severe form than older infants. Even though overall duration of stay was similar for both groups, young infants who in fact did require oxygen had a more protracted and severe illness compared with the older infants. This was evidenced by their longer duration of oxygen and more frequent need to be managed in the intensive care unit.

Clinical Effects of Heliox Administration for Acute Bronchiolitis in Young Infants

To assess the effect of heliox, a helium-oxygen mixture, on respiratory distress symptoms in young infants. Prospective, randomized, double-blind study. Pediatric ICU (PICU) of a university hospital. Twenty infants, all < 3 months old, admitted to the PICU with moderate-to-severe acute respiratory syncytial virus bronchiolitis. All infants were randomly and blindly assigned to inhale either heliox or an air-oxygen mixture (airox) for 1 h under an oxyhood. After 1 h, the respiratory distress score was significantly lower in the heliox group compared with the airox group (3.05 vs 5.5, p < 0.01), with a significant reduction in accessory muscles use (p < 0.05) and expiratory wheezing (p < 0.01). In contrast, inspiratory breath sounds and cyanosis did not significantly differ between groups. The ex-premature infants of the heliox group had a higher respiratory distress score at baseline compared with the term infants of this group (5.8 vs 5.2, p < 0.05) and a comparable decrease in the score at 60 min. In young infants, even those born prematurely, heliox breathing induced a rapid reduction in accessory muscles use and expiratory wheezing. Further studies are needed to confirm the decreased respiratory muscle work of breathing during heliox inhalation in this population.

K1/256 – Clinical effects of heliox administration for acute bronchiolitis in young infants

K1/256 – Clinical effects of heliox administration for acute bronchiolitis in young infants

Rhinovirus and acute bronchiolitis in young infants

To determine the prevalence of rhinovirus infection in hospitalized young infants with acute bronchiolitis. Hospitalized children with acute bronchiolitis admitted to the Hospital São Lucas/PUCRS between May and September 2002 were selected prospectively. Nasopharyngeal samples were assayed for respiratory syncytial virus, parainfluenza, influenza and adenovirus by immunofluorescence. For rhinovirus test a reverse transcription-polymerase chain reaction for picornavirus was used, followed by hybridization with rhinovirus specific probes. Forty-five patients were selected for the study. The median age of the subjects studied was 2 months. Positive samples for respiratory viruses were found in 35/45 (77.8%) subjects and 7/35 (20%) patients had dual infection. Respiratory syncytial virus was detected in 33/35 (94%) cases. Rhinovirus was detected in 6/35 patients (17%). Rhinovirus was the second most common agent detected in nasal secretions from young infants hospitalized with acute bronchiolitis.