Epidemiology of RSV Bronchiolitis Among Young Children in Central New York Before and After the Onset of the COVID-19 Pandemic

The Impact of COVID-19 Pandemic on Respiratory Syncytial Virus Infection in Children

Background/Objective: Respiratory syncytial virus (RSV) is a major cause of bronchiolitis in infants and young children. Bronchiolitis, an acute inflammation of the lower respiratory tract, can lead to pneumonia, respiratory failure, and death. We aimed to compare the incidence and severity of RSV infection in children aged 0-60 months before and during the coronavirus disease 2019 (COVID-19) pandemic. Methods: A retrospective chart review was conducted on patients aged 0-60 months who tested positive for RSV between May 1, 2018, and May 31, 2022, in a community hospital in Queens County, New York City, United States. Comparisons were made between seasons 2018-2019 and 2019-2020 as before, and seasons 2020-2021 and 2021-2022 as during the COVID-19 pandemic. Severity of RSV infection was assessed using the Bronchiolitis Severity Score (BSS). Data were analyzed using R software, a p value of < 0.05 was considered statistically significant. Results: The incidence of RSV infection in seasons 2018-2019 and 2019-2020 peaked from mid-October to February, whereas the first season during the COVID-19 pandemic (2020-2021) was truncated with a very low incidence of RSV infection, and season 2021-2022 peaked from September to January, with the highest incidence (37%) and lower frequency of RSV infection at any given point. Patients during the season 2021-2022 were older (H [2, 196.6] = 12.5, p < 0.001, 95% CI = [5.4, 25.6]) and had milder illness (H [2, 187.5] = 7.5, p < 0.01, 95% CI = [2.1, 19.2]). Conclusions: We observed a lower incidence of RSV infection and a lower rate of hospitalization for RSV during the COVID-19 pandemic. The second RSV season during the COVID-19 pandemic began earlier, lasted longer, and had a lower frequency. Older children with milder illnesses were affected most during this season. RSV epidemiology and disease burden were impacted by the COVID-19 pandemic and could have significant ramifications for its prevention and control strategies.

A Review of Respiratory Syncytial Virus Epidemiology Among Children: Linking Effective Prevention to Vulnerable Populations

Respiratory syncytial virus (RSV) is the greatest contributor to lower respiratory tract infections (LRTI) in children less than 5 years of age and the leading cause for infant hospitalizations in the United States (US). The burden of severe disease disproportionately impacts racial and ethnic minority groups, highlighting the need for interventions that promote health equity. Recent advancements in effective prophylactic agents have the potential to drastically alter the landscape of RSV disease among all young children. The effectiveness of prophylaxis, however, will rely on a clear understanding of RSV epidemiology. The purpose of this review is to discuss key aspects of RSV epidemiology while focusing on efforts to support equitable distribution of prophylactic agents to mitigate existing health disparities.

Bronchiolitis: Increased severity in the post-COVID-19 era

INTRODUCTION

Acute bronchiolitis is a pressing public health concern, leading to numerous infant hospitalizations worldwide annually. The notable decrease in bronchiolitis hospitalizations during the COVID-19 pandemic sparked concerns about a potential resurgence post-pandemic. Questions also arose about the severity of post-pandemic cases compared to prepandemic ones. This study aimed to compare bronchiolitis severity before and after the COVID-19 pandemic, alongside changes in the epidemiology of bronchiolitis viral agents.

MATERIAL AND METHODS

We conducted a retrospective analysis of medical records concerning infants under 12 months hospitalized for acute bronchiolitis in our pediatric pulmonology department over a period of 5 years: 2 pre-COVID years (2018-2020), the COVID year (2020), and 2 post-COVID years (2021-2023). Clinical and laboratory data were collected using standardized forms.

RESULTS

Hospital admissions exhibited comparable rates pre- and post-COVID but witnessed a decline during the COVID period. Post-COVID, bronchiolitis severity increased, with longer hospitalization durations (p < 0.001) and increased oxygen therapy (p = 0.04), coinciding with a surge in the prevalence of RSV infections (p = 0.01). Patients testing positive for RSV were significantly younger (p = 0.005) and exhibited more severe symptoms.

DISCUSSION AND CONCLUSION

This study reveals a significant increase in bronchiolitis severity and a rise in RSV cases following the COVID pandemic. The implementation of preventive measures such as nirsevimab is crucial to alleviate the burden of respiratory illnesses in vulnerable populations. Continued vigilance and research are needed to address the evolving challenges of bronchiolitis in the post-COVID era.

Respiratory Syncytial Virus Bronchiolitis Before and After COVID-19 Pandemic: Has the Immunity Debt Been Paid Off?

BACKGROUND

Our aim was to hypothesize that the COVID-19 pandemic influenced the characteristics of viral bronchiolitis by comparing the last 3 epidemics with 3 pre-COVID-19 epidemics in infants hospitalized with bronchiolitis.

METHODS

We prospectively enrolled 637 consecutive infants (median age 3.0 ± 2.1 months, 58.5% males), hospitalized for bronchiolitis during 6 consecutive annual epidemic seasons from 2017 to 2023. All parents of the children were given a structured anamnestic questionnaire. A nasopharyngeal aspirate was tested for 15 respiratory viruses. As measures of severity, we evaluated the O 2 supplementation and the admission at the pediatric intensive care unit.

RESULTS

A total of 166 were hospitalized with bronchiolitis in 2017-2018, 97 in 2018-2019, 69 in 2019-2020, 0 in 2020-2021, 129 in 2021-2022 and 176 in 2022-2023. Taking together the 332 bronchiolitis cases hospitalized during the 3 prepandemic seasons, they peaked between December and January; after the flat curve in 2020-2021, the cases of bronchiolitis peaked in November 2021 and in December 2022. While the 2021-2022 season registered a less severe clinical presentation, O 2 supplementation and pediatric intensive care unit admissions increased in 2022-2023 with respect to the prepandemic seasons ( P < 0.001).

CONCLUSIONS

This study represents an important scientific demonstration of the impact of primary prevention measures on the epidemiology of viral infections; their fluctuations were related to the intensity of restrictive measures and to the changing trend of respiratory viruses. It is essential to predict the real temporal trend of bronchiolitis not to leave high-risk children uncovered and to guide hospitals to maintain a high level of readiness.

Trends in RSV testing patterns among infants presenting with bronchiolitis: Results from four United States health systems, 2015-2023

BACKGROUND

Bronchiolitis due to respiratory syncytial virus (RSV) is the leading cause of hospitalization among American infants. The overall burden of RSV among infants has been historically under-estimated due to variable testing practices, particularly in the outpatient setting. Universal masking and social distancing implemented during the coronavirus disease 2019 (COVID-19) pandemic altered RSV seasonality, however potential consequences on RSV testing practices across different healthcare settings and sociodemographic groups have not been described. Variable testing practices could also affect accurate assessment of the effects of two recently approved RSV preventative agents targeting infants.

METHODS

Utilizing real-time clinical and viral surveillance, we examined RSV testing practices among infants with bronchiolitis within four United States healthcare systems across different healthcare settings and sociodemographic groups pre- and post-COVID-19.

RESULTS

RSV testing among infants with bronchiolitis increased since 2015 within each healthcare system across all healthcare settings and sociodemographic groups, with a more dramatic increase since the COVID-19 pandemic. Outpatient testing remained disproportionately low compared to hospital-based testing, although there were no major differences in testing frequency among sociodemographic groups in either setting.

CONCLUSIONS

Although RSV testing increased among infants with bronchiolitis, relatively low outpatient testing rates remain a key barrier to accurate RSV surveillance.

Viral infections causing asthma exacerbations in the age of biologics and the COVID-19 pandemic

PURPOSE OF REVIEW

Asthma exacerbations are associated with substantial symptom burden and healthcare costs. Viral infections are the most common identified cause of asthma exacerbations. The epidemiology of viral respiratory infections has undergone a significant evolution during the COVID-19 pandemic. The relationship between viruses and asthmatic hosts has long been recognized but it is still incompletely understood. The use of newly approved asthma biologics has helped us understand this interaction better.

RECENT FINDINGS

We review recent updates on the interaction between asthma and respiratory viruses, and we address how biologics and immunotherapies could affect this relationship by altering the respiratory mucosa cytokine milieu. By exploring the evolving epidemiological landscape of viral infections during the different phases of the COVID-19 pandemic, we emphasize the early post-pandemic stage, where a resurgence of pre-pandemic viruses with atypical seasonality patterns occurred. Finally, we discuss the newly developed RSV and SARS-CoV-2 vaccines and how they reduce respiratory infections.

SUMMARY

Characterizing how respiratory viruses interact with asthmatic hosts will allow us to identify tailored therapies to reduce the burden of asthma exacerbations. New vaccination strategies are likely to shape the future viral asthma exacerbation landscape.

Geographic Progression of Infant Respiratory Syncytial Virus Associated Bronchiolitis Across the United States Before and Since the Onset of COVID-19: Results From Four Health Systems, 2015-2023

BACKGROUND

Respiratory syncytial virus (RSV) is a substantial cause of infant morbidity and mortality due to seasonal peaks of bronchiolitis across the United States. Clinical and viral surveillance plays a pivotal role in helping hospital systems prepare for expected surges in RSV bronchiolitis. Existing surveillance efforts have shown a geographic pattern of RSV positivity across the United States, with cases typically starting in the southeast and spreading north and west. Public health measures implemented due to the COVID-19 pandemic disrupted viral transmission across the nation and altered the expected seasonality of RSV. The impact of these changes on the geographic progression of infant RSV bronchiolitis across the United States has not been described.

METHODS

Here, we used clinical and viral surveillance data from four health care systems located in different regions of the United States to describe the geographic progression of infant RSV bronchiolitis across the country from 2015 to 2023.

RESULTS

Prior to widespread circulation of SARS-CoV-2, infant RSV bronchiolitis followed an established geographic pattern associated with seasonal epidemics originating in Florida and spreading north (North Carolina and New York) and later westward (Nevada). Although public health and social measures implemented during the COVID-19 pandemic disrupted the seasonality of RSV disease, infant RSV bronchiolitis epidemics progressed across the nation in a pattern identical to the prepandemic era.

CONCLUSIONS

Our findings highlight the importance of ongoing clinical and viral surveillance to optimally track the onset of RSV epidemics and allow health care systems to prepare for expected RSV bronchiolitis surges.

Epidemiological shifts in bronchiolitis patterns and impact of the COVID-19: A two-season comparative study

BACKGROUND

Bronchiolitis is a common lower respiratory tract infection (LRTI) affecting infants and young children. Respiratory syncytial virus (RSV) has historically been the primary causative agent, but other viruses also contribute to the LRTI epidemiology. Recent changes in epidemiology and clinical patterns due to the coronavirus disease 2019 (COVID-19) pandemic have raised concerns. This study aims to analyze the impact of the pandemic on bronchiolitis epidemiology and severity.

METHODS

Two consecutive bronchiolitis seasons (October 2021 to March 2022 and October 2022 to March 2023) were compared. Data on viral agents, hospitalization duration, clinical severity, and respiratory support requirements were collected from pediatric patients at San Marco Hospital, University of Catania.

RESULTS

In the 2021-2022 season, RSV was the predominant virus (40%), followed by other viruses, with mild clinical outcomes. In the 2022-2023 season, RSV remained prevalent (58.7%), but other viruses, including rhinovirus (RV) and influenza, showed a significant increase (p < .05) in bronchiolitis cases and severity. Notably, RSV-related bronchiolitis did not exhibit greater severity compared to non-RSV cases in the 2022-2023 season, contrary to the previous year.

CONCLUSION

The COVID-19 pandemic appears to have shifted the epidemiological landscape of bronchiolitis, with a peak incidence in November instead of January/February. Non-RSV viruses (RV, influenza A and B, as well as metapneumovirus) have gained prominence, possibly due to viral competition and reduced pandemic-related restrictions. Traditionally, RSV has been the primary pathogen responsible for most bronchiolitis cases. Nonetheless, the findings of this study indicate a shifting landscape in bronchiolitis etiology, with RSV gradually diminishing in its role. Contrary to the previous year, RSV-related bronchiolitis did not exhibit greater severity compared to non-RSV cases in the 2022-2023 season.