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.

SIGNIFICANCE: What is KnownThe main etiological agent of acute bronchiolitis (AB) is respiratory syncytial virus (RSV); however, other viruses are frequently detected. All viruses may be the sole etiological cause or may occur in association, and a high prevalence of viral coinfection has been described.To date, there are conflicting results on the role of viral coinfections in the severity of bronchiolitis.What is NewViral coinfections influence the progression of AB. The simultaneous detection of 3 or more respiratory viruses is a risk factor for longer hospital stay.The presence of viral coinfections does not condition a greater need for admission to the PICU.

Influencia de la pandemia COVID-19 sobre la epidemiología de la bronquiolitis aguda / Influence of the COVID-19 pandemic on the epidemiology of acute bronchiolitis

Introducción: La pandemia COVID-19ha modificado la propagación de ciertos virus respiratorios causantes de bronquiolitis aguda. Analizamos la epidemiología de los ingresos por bronquiolitis durante la pandemia COVID-19 en comparación con ocho temporadas epidémicas anteriores. Métodos: Estudio observacional ambispectivo, que incluyó lactantes con bronquiolitis ingresados en un hospital terciario durante dos períodos: pandemia COVID-19 (15 de marzo de 2020 a 31 de agosto de 2021) y pre-pandemia (1 de septiembre de 2012 a 14 de marzo de 2020). Se recogieron características demográficas, clínicas y etiología. Resultados: Ingresaron 510 pacientes por bronquiolitis: 486 en el período pre-pandemia con una media de 61 ingresos por temporada vs. 24 durante la pandemia, observándose una reducción de ingresos del 60,7%. Durante la pandemia, el brote epidémico se inició con retraso abarcando la primavera-verano de 2021. El virus respiratorio sincitial fue el agente etiológico más frecuente en ambos períodos. Conclusiones: Observamos un cambio estacional de la bronquiolitis durante la pandemia COVID-19, probablemente influenciado por las medidas de control frente a SARS-CoV-2.(AU)

Introduction: The COVID-19 pandemic has changed the circulation of some viruses associated with acute bronchiolitis. We analyzed the epidemiology of bronchiolitis admissions during the COVID-19 pandemic compared with 8 previous epidemic seasons. Methods: An observational and ambispective study was performed, including infants admitted with bronchiolitis in a tertiary hospital during 2 periods: COVID-19 pandemic (15th March 2020 to 3rd August 2021) and pre-pandemic (1st September 2012 to 14th March 2020). Demographic, clinical data and etiologies were collected. Results: Five hundred ten patients were hospitalized with bronchiolitis: 486 in the pre-pandemic period with an average of 61 admissions per season vs. 24 during the pandemic, observing a 60.7% reduction in bronchiolitis admissions. During the pandemic, bronchiolitis outbreak was delayed until spring–summer 2021. Respiratory syncytial virus was the most frequent etiological agent in both periods. Conclusion: We observed a change in the seasonality of bronchiolitis during the pandemic COVID-19, possibly influenced by control measures against SARS-CoV-2..(AU)

[Influence of the COVID-19 pandemic on the epidemiology of acute bronchiolitis]. / Influencia de la pandemia COVID-19 sobre la epidemiología de la bronquiolitis aguda.

Introduction: The COVID-19 pandemic has changed the circulation of some viruses associated with acute bronchiolitis. We analyzed the epidemiology of bronchiolitis admissions during the COVID-19 pandemic compared with 8 previous epidemic seasons. Methods: An observational and ambispective study was performed, including infants admitted with bronchiolitis in a tertiary hospital during 2 periods: COVID-19 pandemic (15th March 2020 to 3 rd August 2021) and pre-pandemic (1st September 2012 to 14th March 2020). Demographic, clinical data and etiologies were collected. Results: Five hundred ten patients were hospitalized with bronchiolitis: 486 in the pre-pandemic period with an average of 61 admissions per season vs. 24 during the pandemic, observing a 60.7% reduction in bronchiolitis admissions. During the pandemic, bronchiolitis outbreak was delayed until spring-summer 2021. Respiratory syncytial virus was the most frequent etiological agent in both periods. Conclusion: We observed a change in the seasonality of bronchiolitis during the pandemic COVID-19, possibly influenced by control measures against SARS-CoV-2.

Influence of the COVID-19 pandemic on the epidemiology of acute bronchiolitis.

INTRODUCTION: The COVID-19 pandemic has changed the circulation of some viruses associated with acute bronchiolitis. We analyzed the epidemiology of bronchiolitis admissions during the COVID-19 pandemic compared with 8 previous epidemic seasons. METHODS: An observational and ambispective study was performed, including infants admitted with bronchiolitis in a tertiary hospital during 2 periods: COVID-19 pandemic (15th March 2020 to 3rd August 2021) and pre-pandemic (1st September 2012 to 14th March 2020). Demographic, clinical data and etiologies were collected. RESULTS: Five hundred ten patients were hospitalized with bronchiolitis: 486 in the pre pandemic period with an average of 61 admissions per season vs 24 during the pandemic, observing a 60.7% reduction in bronchiolitis admissions. During the pandemic, bronchiolitis outbreak was delayed until spring-summer 2021. Respiratory syncytial virus was the most frequent etiological agent in both periods. CONCLUSION: We observed a change in the seasonality of bronchiolitis during the pandemic COVID-19, possibly influenced by control measures against SARS-CoV-2.

Variation in the seasonality of the respiratory syncytial virus during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has caused a variation in the circulation of common respiratory viruses. Our objective was to analyse the epidemiology of respiratory syncytial virus (RSV) bronchiolitis admissions during the COVID-19 pandemic in comparison with previous epidemic seasons. METHODS: We conducted an observational study involving infants with RSV bronchiolitis admitted to a tertiary hospital during two periods: pandemic COVID-19 (15 March 2020-30 September 2021) and pre-pandemic (1 October 2014-14 March 2020). Demographic and clinical characteristics were collected. RESULTS: A total of 270 patients were admitted for RSV bronchiolitis: 253 in the pre-pandemic period with an average of 42 admissions per season vs 17 in the pandemic. During the pandemic, the RSV outbreak started late in June 2021 with a higher percentage of prematurity and PICU admissions. CONCLUSION: A change in RSV seasonality was observed during the COVID-19 pandemic, with an unusual outbreak in summer 2021 of lower magnitude than previous seasons.