Risk factors for respiratory syncytial virus bronchiolitis hospitalizations in children with chronic diseases

Risk Factors for Poor Outcomes in Children Hospitalized With Virus-associated Acute Lower Respiratory Infections: A Systematic Review and Meta-analysis

BACKGROUND

Acute lower respiratory infection (ALRI) caused by respiratory viruses is among the most common causes of hospitalization and mortality in children. We aimed to identify risk factors for poor outcomes in children <5 years old hospitalized with ALRI caused by respiratory syncytial virus (RSV), influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We searched Embase, Medline and Global Health databases and included observational studies reporting risk factors for poor outcomes (defined as use of supplemental oxygen, mechanical ventilation, intensive care unit admission, prolonged hospital stay and mortality) published between January 2011 and January 2023. Two authors independently extracted data on study characteristics, outcomes and risk factors. Due to limited data, meta-analyses were only conducted for RSV-ALRI poor outcome risk factors using random effects model when there were at least 3 studies.

RESULTS

We included 30 studies. For RSV-related ALRI, significant risk factors based on meta-analysis were: neurological disease [odds ratio (OR): 6.14; 95% confidence intervals (CIs): 2.39-15.77], Down's syndrome (5.43; 3.02-9.76), chronic lung disease (3.64; 1.31-10.09), immunocompromised status (3.41; 1.85-6.29), prematurity (2.98; 1.93-4.59), congenital heart disease (2.80; 1.84-4.24), underlying disease (2.45; 1.94-3.09), age <2 months (2.29; 1.78-2.94), age <6 months (2.08; 1.81-2.39), viral coinfection (2.01; 1.27-3.19), low birth weight (1.88; 1.19-2.95) and being underweight (1.80; 1.38-2.35). For influenza-related ALRI, chronic conditions and age 6-24 months were identified as risk factors for poor outcomes. Cardiovascular disease, immunosuppression, chronic kidney disease, diabetes and high blood pressure were reported as risk factors for mortality due to SARS-CoV-2 associated ALRI.

CONCLUSIONS

These findings might contribute to the development of guidelines for prophylaxis and management of ALRI caused by RSV, influenza and SARS-CoV-2.

Resurgence of human respiratory syncytial virus during COVID-19 pandemic in Southern Brazil

Respiratory Syncytial Virus (RSV) is an important cause of respiratory infection in humans. Severe cases are common in children ≤2 years old, immunocompromised individuals, and the elderly. In 2020, RSV infection reduced in Rio Grande do Sul (RS), southern Brazil; however, in 2021 resurgence of RSV was observed. This study analyzed epidemiological and genetic features of RSV infection cases reported in 2021 in RS. Nasopharyngeal samples collected from individuals with respiratory infection negative for SARS-CoV-2, Influenza A and B viruses were assessed for the presence of RSV by real time RT-qPCR. RSV-A and RSV-B genomic sequencing and phylogenetic reconstructions were performed for genotyping and clade characterization. Among 21,035 respiratory samples analyzed, 2,947 were positive for RSV, 947 of which were hospitalized patients. Positive cases were detected year-round, with the highest number in June-July (winter). Children <1 year comprised 56.28% (n = 533) of the hospitalized patients infected with RSV, whereas 14.46% (n = 137) were individuals >60 years. Of a total of 361 deaths, 14.68% (n = 53) were RSV positive, mostly patients >60 years old (73.58%, n = 39). Chronic kidney disease, cardiopathy, Down syndrome and neurological diseases were associated with RSV infection. RSV-A was identified in 58.5% (n = 117/200) of the patients, and RSV-B in 41.5% (n = 83/200). Of 95 RSV genomes recovered from SARI cases, 66 were RSV-A GA.2.3.5 genotype, while 29 were RSV-B GB.5.0.5a genotype. This study provides epidemiological and molecular data on RSV cases in RS during the COVID-19 pandemic and highlights that investigation of different respiratory viruses is essential for decision-making and disease prevention and control measures.

Inpatient burden of respiratory syncytial virus in children ≤2 years of age in Germany: A retrospective analysis of nationwide hospitalization data, 2019-2022

BACKGROUND

Respiratory syncytial virus (RSV) causes respiratory tract disease in seasonal waves, primarily in infants and young children. This study aims to quantify the number of RSV-related hospitalizations in children ≤2 years of age and to determine corresponding resource use and costs in Germany.

METHODS

We retrospectively analyzed population-wide hospital data from the Institute for the Hospital Remuneration System (InEK) from 2019 to 2022. RSV cases were identified using the RSV-specific 10th revision of the International Classification of Diseases (ICD-10) codes J12.1, J20.5, and J21.0. The RSV-associated proportion of all hospitalizations caused by severe acute respiratory infections (SARIs), clinical manifestations, length of stay (LOS), intensive care unit (ICU) admissions, ventilation rates, and hospitalization costs were retrieved.

RESULTS

We identified 98,220 hospitalizations (26,052, 15,407, 31,362, and 25,399 in 2019, 2020, 2021, and 2022, respectively) with a principal RSV diagnosis in children aged ≤2 years in Germany. The majority of RSV hospitalizations (73,178) occurred in infants (<1 year), with annual incidence rates ranging from 14.9 to 28.6 per 1000 population. Fifty-eight percent of all SARI hospitalizations in this age group were attributable to RSV. In children aged ≤2 years, mean LOS was 4.5 days, 6.1% of cases were admitted to ICU, and 5.3% of cases were ventilated. Mean hospitalization costs per case ranged from €3001 to €3961 over the study period.

CONCLUSIONS

RSV causes substantial disease burden and is a leading cause of SARI-related hospital admissions of children ≤2 years of age in Germany. Our results confirm the need to explore and evaluate strategies to prevent RSV in infants and young children.

Risk of RSV-related hospitalization is associated with gestational age in preterm (born at 29-34 wGA) infants without outpatient palivizumab administration

Palivizumab has been shown to decrease RSV-related hospitalization (RSVH) risk and reduce RSVH severity. American Academy of Pediatrics (AAP) guidance on administration of palivizumab has changed over time; in 2014, palivizumab was no longer recommended in preterm infants born at 29 weeks gestational age (wGA) or later. This study's objective was to describe RSVH risk and severity in preterm infants (29-34 wGA) without comorbidities relative to healthy term infants and to each other by gestational age. Using the MarketScan Multi-State Medicaid and Commercial Databases, infants born from July 1, 2014 to June 30, 2019, at 29-34 wGA (preterm) and >37 wGA (term) were identified. During RSV seasons (November to March) from 2014 to 2020, claims incurred by infants while they were <6 months old were evaluated for RSVH and RSVH characteristics. This study included 63,351 preterm infants and 1,076,389 term infants without outpatient palivizumab administration. Rate of RSVH was higher in infants with lower wGA at birth and ranged 3.32-5.72 per 100 infant-seasons in Medicaid-insured infants and 3.21-4.84 in commercially insured infants. Relative risk of RSVH was 5-8 times higher in Medicaid-insured preterm infants and 3-5 times higher in commercially insured preterm infants compared to term infants. ICU admissions and mechanical ventilation were more common during RSVH in preterm infants relative to term infants. RSV-related outpatient healthcare utilization was also 2-3 times higher in preterm infants born at 31-34 wGA. Increased utilization of palivizumab among infants born at 29-34 wGA may decrease RSVH rates and result in less severe course in preterm infants with RSVH.

Case-control study of exclusive breast feeding and severe bronchiolitis in the United States

BACKGROUND

Bronchiolitis is a major cause of infant illness, with few known modifiable risk factors. Breast feeding may reduce risk of severe bronchiolitis, but the association of exclusive vs. partial breast feeding with severe bronchiolitis is unclear.

OBJECTIVE

To estimate the association of exclusive vs. partial breast feeding during ages 0-2.9 months with bronchiolitis hospitalisation during infancy.

METHODS

We conducted a case-control study as a secondary analysis of two prospective US cohorts in the Multicenter Airway Research Collaboration. Cases were enrolled in a 17-centre study of infants hospitalised for bronchiolitis during 2011-2014 (n = 921). Controls were enrolled in a five-centre study of healthy infants during 2013-2014 and 2017 (n = 719). Breast feeding history during ages 0-2.9 months was collected by parent interview. Among breastfed infants, the association of exclusive vs. partial breast feeding with odds of bronchiolitis hospitalisation was estimated using a multivariable logistic regression model adjusted for demographic variables, parental asthma history, and early-life exposures. As a secondary analysis, we estimated the associations of exclusive, predominant, and occasional breast feeding vs. no breast feeding with the odds of bronchiolitis hospitalisation.

RESULTS

Among 1640 infants, the prevalence of exclusive breast feeding was 187/921 (20.3%) among cases and 275/719 (38.3%) among controls. Exclusive vs. partial breast feeding was associated with 48% reduced odds of bronchiolitis hospitalisation (adjusted odds ratio [OR] 0.52, 95% confidence interval [CI] 0.39, 0.69). In the secondary analysis, exclusive vs. no breast feeding was associated with 58% reduced odds of bronchiolitis hospitalisation (OR 0.42, 95% CI 0.23, 0.77), whereas predominant breast feeding (OR 0.77, 95% CI 0.37, 1.57) and occasional breast feeding (OR 0.98, 95% CI 0.57, 1.69) were not associated with meaningfully reduced odds of bronchiolitis hospitalisation.

CONCLUSION

Exclusive breast feeding had a strong protective association against bronchiolitis hospitalisation.

Clinical practice guidelines: management of severe bronchiolitis in infants under 12 months old admitted to a pediatric critical care unit

PURPOSE

We present guidelines for the management of infants under 12 months of age with severe bronchiolitis with the aim of creating a series of pragmatic recommendations for a patient subgroup that is poorly individualized in national and international guidelines.

METHODS

Twenty-five French-speaking experts, all members of the Groupe Francophone de Réanimation et Urgence Pédiatriques (French-speaking group of paediatric intensive and emergency care; GFRUP) (Algeria, Belgium, Canada, France, Switzerland), collaborated from 2021 to 2022 through teleconferences and face-to-face meetings. The guidelines cover five areas: (1) criteria for admission to a pediatric critical care unit, (2) environment and monitoring, (3) feeding and hydration, (4) ventilatory support and (5) adjuvant therapies. The questions were written in the Patient-Intervention-Comparison-Outcome (PICO) format. An extensive Anglophone and Francophone literature search indexed in the MEDLINE database via PubMed, Web of Science, Cochrane and Embase was performed using pre-established keywords. The texts were analyzed and classified according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. When this method did not apply, an expert opinion was given. Each of these recommendations was voted on by all the experts according to the Delphi methodology.

RESULTS

This group proposes 40 recommendations. The GRADE methodology could be applied for 17 of them (3 strong, 14 conditional) and an expert opinion was given for the remaining 23. All received strong approval during the first round of voting.

CONCLUSION

These guidelines cover the different aspects in the management of severe bronchiolitis in infants admitted to pediatric critical care units. Compared to the different ways to manage patients with severe bronchiolitis described in the literature, our original work proposes an overall less invasive approach in terms of monitoring and treatment.

Changes in T-Cell Subsets and Serum IFN-γ, IL-17, and IgE Levels in Children with Respiratory Syncytial Virus Capillary Bronchitis and Their Clinical Significance

Objective

To investigate the changes in T-cell subsets and serum IFN-γ, IL-17, and IgE levels in children with respiratory syncytial virus capillary bronchitis and their clinical significance.

Methods

The clinical data of 50 children with respiratory syncytial virus capillary bronchitis admitted to our hospital between July 2020 and June 2021 were retrospectively reviewed, and they were included in the observation group, while 50 children with a healthy physical examination during the same period were chosen as the control group. The T-cell subsets (CD4, CD8, and CD4/CD8) and serum IL-4, IL-8, IFN-, IL-17, and IgE levels of children in the two groups were compared, and the clinical significance of the changes in the levels of the indices mentioned above was analyzed.

Results

There was no statistically significant difference in T-cell subset levels (CD4 and CD8) between the two groups (P > 0.05); the level of CD4/CD8, IL-4, IL-8, IL-17, and IgE in the observation group were substantially higher than those in the control group (P < 0.05), while the serum IFN-γ levels in the observation group were significantly lower than those in the control group (P < 0.05).

Conclusion

Increased CD4/CD8 levels in children with respiratory syncytial virus capillary bronchitis cause an imbalance in the Th1/Th2 immune response, similar to changes in bronchial asthma, suggesting a link between the two diseases. Increased serum levels of IL-4, IL-8, IL-17, and IgE and decreased serum levels of IFN-γ have been seen in children with respiratory syncytial virus capillary bronchitis, suggesting the severity of the children's disease may in part be reflected in the levels of the aforementioned serum indicators.

Incidence and risk factors of hospitalisations for respiratory syncytial virus among children aged less than two years

The study aim was to examine the incidence and risk factors of respiratory syncytial virus (RSV) bronchiolitis hospitalisations and disease severity among infants. We compared demographic and health characteristics of children aged 0–23 hospitalised for RSV bronchiolitis (cases, n = 1227) during 2008–2018 and control children (n = 554) of the same age admitted for non-respiratory disease. RSV antigen was detected in nasal swabs by immunochromatography. Multiple logistic regression models were applied. The average annual incidence of hospitalisation for RSV bronchiolitis was 12.6 per 1000 and 1.7 per 1000 (P < 0.001) among infants and toddlers, respectively, with winter seasonality (November–March). The risk of hospitalisation for RSV bronchiolitis increased among children aged 0–5 months (OR 7.66; 95% CI 5.61–10.45) and 6–11 months (OR 12.88, 95% CI 8.48–19.55), compared to those aged 12–23 months. Additional risk factors were living in low vs. higher socio-economic status towns (OR 1.49; 95% CI 1.14–1.95), having chronic medical conditions (OR 2.75; 95% CI 1.61–4.70), birth month (October–January vs. June–September) (OR 2.19; 95% CI 1.60–2.99) and history of stay in neonatal intensive care unit at birth (OR 2.37; 95% CI 1.27–4.41). Male children and those who had pneumonia were more likely to have severe RSV bronchiolitis. In conclusion, the burden of hospitalisations for RSV bronchiolitis is high, especially in young infants. Effective preventive measures such as RSV active vaccines can reduce the risk of hospitalisations for RSV bronchiolitis among these vulnerable groups.