New epidemiological trends of respiratory syncytial virus bronchiolitis during COVID-19 pandemic

Impact of Nirsevimab Immunization on Pediatric Hospitalization Rates: A Systematic Review and Meta-Analysis (2024)

A systematic review with a meta-analysis was performed to gather available evidence on the effectiveness of monoclonal antibody nirsevimab in the prevention of lower respiratory tract diseases (LRTDs) due to respiratory syncytial virus (RSV) in children and newborns (CRD42024540669). Studies reporting on real-world experience and randomized controlled trials (RCTs) were searched for in three databases (PubMed, Embase, and Scopus) until 1 May 2024. Our analysis included five RCTs, seven real-world reports, and one official report from the health authorities. Due to the cross-reporting of RCTs and the inclusion of multiple series in a single study, the meta-analysis was performed on 45,238 infants from 19 series. The meta-analysis documented a pooled immunization efficacy of 88.40% (95% confidence interval (95% CI) from 84.70 to 91.21) on the occurrence of hospital admission due to RSV, with moderate heterogeneity (I2 24.3%, 95% CI 0.0 to 56.6). Immunization efficacy decreased with the overall length of the observation time (Spearman's r = -0.546, p = 0.016), and the risk of breakthrough infections was substantially greater in studies with observation times ≥150 days compared to studies lasting <150 days (risk ratio 2.170, 95% CI 1.860 to 2.532). However, the effect of observation time in meta-regression analysis was conflicting (β = 0.001, 95% CI -0.001 to 0.002; p = 0.092). In conclusion, the delivery of nirsevimab was quite effective in preventing hospital admissions due to LRTDs. However, further analyses of the whole RSV season are required before tailoring specific public health interventions.

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.

Trends in emergency department visits for bronchiolitis, 1993-2019

INTRODUCTION

Bronchiolitis is a leading indication for pediatric emergency department (ED) visits and hospitalizations. Our objective was to provide a comprehensive review of national trends and epidemiology of ED visits for bronchiolitis from 1993 to 2019 in the United States.

METHODS

We retrospectively reviewed the National Hospital Ambulatory Medical Care Survey (NHAMCS) reporting of ED visits for bronchiolitis for children age <2 years from 1993 to 2019. Bronchiolitis cases were identified using billing codes assigned at discharge. The primary outcome was bronchiolitis ED visit rates, calculated using NHAMCS-assigned patient visit weights. We then evaluated for temporal variation in patient characteristics, facility location, and hospitalizations among the bronchiolitis ED visits.

RESULTS

There were an estimated 8 million ED visits for bronchiolitis for children <2 years between 1993 and 2019. Bronchiolitis ED visits rates ranged from 28 to 36 per 1000 ED visits from 1993 to 2010 and increased significantly to 65 per 1000 ED visits in the 2017-2019 time period (p < 0.001). There was no significant change over time in patient age, sex, race and ethnicity, insurance status, hospital type, or triage level upon ED presentation. Approximately half of bronchiolitis ED visits occurred in the winter months throughout the study period.

CONCLUSION

In this analysis of 27 years of national data, we identified a recent rise in ED visit rates for bronchiolitis, which have almost doubled from 2010 to 2019 following a period of relative stability between 1993 and 2010.

Expert consensus on the diagnosis, treatment, and prevention of respiratory syncytial virus infections in children

BACKGROUND

Respiratory syncytial virus (RSV) is the leading global cause of respiratory infections and is responsible for about 3 million hospitalizations and more than 100,000 deaths annually in children younger than 5 years, representing a major global healthcare burden. There is a great unmet need for new agents and universal strategies to prevent RSV infections in early life. A multidisciplinary consensus development group comprising experts in epidemiology, infectious diseases, respiratory medicine, and methodology aims to develop the current consensus to address clinical issues of RSV infections in children.

DATA SOURCES

The evidence searches and reviews were conducted using electronic databases, including PubMed, Embase, Web of Science, and the Cochrane Library, using variations in terms for "respiratory syncytial virus", "RSV", "lower respiratory tract infection", "bronchiolitis", "acute", "viral pneumonia", "neonatal", "infant" "children", and "pediatric".

RESULTS

Evidence-based recommendations regarding diagnosis, treatment, and prevention were proposed with a high degree of consensus. Although supportive care remains the cornerstone for the management of RSV infections, new monoclonal antibodies, vaccines, drug therapies, and viral surveillance techniques are being rolled out.

CONCLUSIONS

This consensus, based on international and national scientific evidence, reinforces the current recommendations and integrates the recent advances for optimal care and prevention of RSV infections. Further improvements in the management of RSV infections will require generating the highest quality of evidence through rigorously designed studies that possess little bias and sufficient capacity to identify clinically meaningful end points.

The changing virology and trends in resource utilization for bronchiolitis since COVID-19

BACKGROUND

Bronchiolitis is a viral respiratory illness most commonly caused by respiratory syncytial virus (RSV). COVID-19 disrupted typical patterns of viral transmission. Our study aimed to compare low value care for bronchiolitis in a tertiary emergency department (ED) in the United States from March 2017 to March 2022.

METHODS

This was a descriptive cohort study through a retrospective chart review from 2017 to 2022 analyzing ED visits for bronchiolitis including disposition, disease severity, chest radiographs, albuterol, and high flow nasal cannula usage. A year was a 12-month period from March to February.

RESULTS

From 2017 to 2020, there were over 2000 ED visits for bronchiolitis per year (3.1% of all ED visits), which decreased to 450 visits for bronchiolitis (1%) in 2020-2021. Human rhino/enterovirus was the most common virus detected (92%) at that time, and admission rates, albuterol, high flow nasal cannula, and chest radiographs were all higher. The summer of 2021 had the highest visits across the 5-study years with a return to previous rates of resource utilization.

CONCLUSIONS

Bronchiolitis ED visits due to RSV dramatically reduced during the first year of the COVID-19 pandemic in 2020, with over 80% reduction in bronchiolitis visits from 2018 to 2019. While all ED visits fell in 2020, the proportion of visits due to bronchiolitis also decreased. There was an increase in lower value care during the rhinovirus dominant, low census period. As restrictions lifted in 2021, there was a large resurgence of RSV in the atypical summer months with a return of previous rates of resource utilization.

Respiratory Syncytial Virus: A Systematic Review and Meta-Analysis of Tomographic Findings (2000-2022)

Human respiratory syncytial virus (RSV) is a main cause of medical referrals and hospitalizations in all infants, particularly among newborns. Nevertheless, relatively limited evidence on chest tomography (CT) findings has been collected. According to the PRISMA statement, Pubmed, Embase, and medRxiv were searched for eligible observational studies published up to 31 December 2022. Cases were categorized in children and adolescents (age < 18 years), adults and elderly (age ≥ 18 years), and immunocompromised patients, and then pooled in a random-effects model. Heterogeneity was assessed using the I2 statistics, while reporting bias was assessed by means of funnel plots and regression analysis. A total of 10 studies (217 RSV cases) were retrieved (children, 37.3%; immunocompromised, 41.0%; adults, 21.7%). The most common features were signs of organizing pneumonia (33.65%, 95% confidence interval [95% CI] 22.39-47.27), followed by septal thickening (33.19%, 95% CI 21.76-47.03), ground glass opacities (GGOs; 28.03%, 95% CI 14.69-46.82), and tree-in-bud (TIB, 27.44%, 95% CI 15.04-44.68). Interestingly, up to 16.23% (95% CI 8.17-29.69) showed normal findings, while the large majority (76.06%, 95% CI 64.81-84.56) were characterized by bilateral involvement. Studies were highly heterogeneous without substantial reporting bias. Assuming children and adolescents as reference groups, healthy adults were characterized by a higher risk ratio [RR] for septal thickening (RR 3.878, 95% CI 1.253-12.000), nodular lesions (RR 20.197, 95% CI 1.286-317.082), and GGOs (RR 2.121, 95% CI 1.121-4.013). RSV cases are rarely assessed in terms of CT characteristics. Our study identified some specificities, suggesting that RSV infections evolve heterogeneous CT features in children/adolescents and adults, but the paucity of studies recommends a cautious appraisal.

Real-Time Monitoring of Infectious Disease Outbreaks with a Combination of Google Trends Search Results and the Moving Epidemic Method: A Respiratory Syncytial Virus Case Study

The COVID-19 pandemic has disrupted the seasonal patterns of several infectious diseases. Understanding when and where an outbreak may occur is vital for public health planning and response. We usually rely on well-functioning surveillance systems to monitor epidemic outbreaks. However, not all countries have a well-functioning surveillance system in place, or at least not for the pathogen in question. We utilized Google Trends search results for RSV-related keywords to identify outbreaks. We evaluated the strength of the Pearson correlation coefficient between clinical surveillance data and online search data and applied the Moving Epidemic Method (MEM) to identify country-specific epidemic thresholds. Additionally, we established pseudo-RSV surveillance systems, enabling internal stakeholders to obtain insights on the speed and risk of any emerging RSV outbreaks in countries with imprecise disease surveillance systems but with Google Trends data. Strong correlations between RSV clinical surveillance data and Google Trends search results from several countries were observed. In monitoring an upcoming RSV outbreak with MEM, data collected from both systems yielded similar estimates of country-specific epidemic thresholds, starting time, and duration. We demonstrate in this study the potential of monitoring disease outbreaks in real time and complement classical disease surveillance systems by leveraging online search data.

The Importance of RSV Epidemiological Surveillance: A Multicenter Observational Study of RSV Infection during the COVID-19 Pandemic

The restrictive measures adopted worldwide against SARS-CoV-2 produced a drastic reduction in respiratory pathogens, including RSV, but a dramatic rebound was thereafter reported. In this multicenter retrospective observational study in 15 Pediatric Emergency Departments, all children <3 years old with RSV infection admitted between 1 September and 31 December 2021 were included and compared to those admitted in the same period of 2020 and 2019. The primary aim was to evaluate RSV epidemiology during and after the COVID-19 pandemic peak. The secondary aims were to evaluate the clinical features of children with RSV infection. Overall, 1015 children were enrolled: 100 in 2019, 3 in 2020 and 912 in 2021. In 2019, the peak was recorded in December, and in 2021, it was recorded in November. Comparing 2019 to 2021, in 2021 the median age was significantly higher and the age group 2-3 years was more affected. Admissions were significantly higher in 2021 than in 2020 and 2019, and the per-year hospitalization rate was lower in 2021 (84% vs. 93% in 2019), while the duration of admissions was similar. No difference was found in severity between 2019-2020-2021. In conclusion, after the COVID-19 pandemic, an increase in RSV cases in 2021 exceeding the median seasonal peak was detected, with the involvement of older children, while no difference was found in severity.

Infodemiology of RSV in Italy (2017-2022): An Alternative Option for the Surveillance of Incident Cases in Pediatric Age?

The aim of this study was to evaluate whether or not online queries for Respiratory Syncytial Virus (RSV) retrieved by means of Google Trends™ and the Italian Wikipedia analysis program mirror the occurrence of influenza-like illnesses (ILI), as reported by the Italian Influenza Surveillance network (InfluNet). Estimated rates for ILI in the general population and in the age groups 0−4 years and 5−14 years were obtained for the influenza seasons 2017−2018 to 2020−2021. Similarly, a weekly fraction of online searches was retrieved for a series of terms associated with Respiratory Syncytial Virus. Next, trends for daily visualization of Italian Wikipedia Pages for Human Respiratory Syncytial Virus, Pneumonia, Bronchiolitis, Influenza, and Respiratory Failure were similarly retrieved. The correlation of all search terms with ILI was analyzed by means of Spearman’s rank correlation analysis. Among search terms associated with the clinical diagnosis of Respiratory Syncytial Virus infections, the occurrence of ILI was highly correlated only with Bronchiolitis in the age group 0−4 years (β 0.210, p = 0.028), while more generic search terms, such as Bronchitis, fever, influenza, and Pneumonia, were identified as effective predictors of ILI, in general and by age groups. In a regression analysis modeled with ILIs as the outcome variable, daily visualizations for the Wikipedia pages on Bronchiolitis were identified as negative predictors for ILI in general (β = −0.152, p = 0.032), ILI in age group 0−4 years (β = −0.264, p = 0.001) and 5−14 years (β = −0.202, p = 0.006), while Influenza was characterized as a positive effector for ILIs in the age group 5−14 years (β = 0.245, p = 0.001). Interestingly, not only were the search terms extensively correlated with one another, but all of them were also characterized by autocorrelation through a Durbin-Watson test (all estimates DW < 2.0) In summary, our study identified a complicated pattern of data visualization as no clear association between rates of ILI in pediatric age group 0−4 and 5 to 14 years was actually found. Finally, our data stress that the infodemiology option may be quite problematic for assessing the time trend of RSV infections in Italy until more appropriate reporting will be made available, by sharing estimates of Lower Respiratory Tract Infections, and through a more accurate characterization of younger age groups.