Clinical Phenotype of Respiratory Syncytial Virus Bronchiolitis before and during the Coronavirus Disease 2019 Pandemic

Abstract

Objective The main objective of this report was to comprehensively analyze the clinical characteristics of children hospitalized with respiratory syncytial virus (RSV) infections in 2021 during the coronavirus disease 2019 (COVID-19) pandemic and to compare them with those in the five previous RSV seasons. We hypothesized that the clinical and demographic features of children hospitalized with RSV infection in 2021 were different from those hospitalized in previous respiratory seasons.

Study Design In this retrospective observational study, children younger than 2 years hospitalized with RSV bronchiolitis from January 1, 2015, to December 31, 2021, at the Department of Pediatrics of the Hospital Gregorio Marañón, Madrid, Spain, were included. We compared the clinical characteristics of children hospitalized with RSV bronchiolitis in the five seasons before the COVID-19 pandemic and during the subsequent off-seasonal surge of RSV infections.

Results We found a significant reduction in hospitalizations for RSV bronchiolitis during the usual winter epidemic period due to the COVID-19 pandemic. Children hospitalized with RSV infection in 2021, during the COVID-19 pandemic, were older than children hospitalized in the prepandemic period (2015–2020; 4.0 [1.6–9.2] vs. 3 [1.5–6.5] months; p < 0.01). We also found shorter duration of oxygen days during the COVID-19 period compared with previous respiratory seasons (3 [2–5] vs. 4 [2–6] days; p = 0.02).

Conclusion The COVID-19 pandemic modified the RSV seasonality with a significant reduction in RSV hospitalizations during the expected 2020–2021 season and a reappearance of RSV 7 months later than expected. We also found changes in the median age of children with RSV bronchiolitis during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic compared with the prepandemic RSV seasons and shorter duration of oxygen days suggesting a modest reduction in disease severity. We hypothesize that this observation reflects the lack of RSV circulation in the previous months (April 2020-March 2021), with a larger pool of vulnerable infants that had not been previously infected.

Key Points

• The COVID-19 pandemic shifted RSV seasonality.

• RSV children hospitalized during the pandemic were older.

• Modest reduction in disease severity was observed during the pandemic.

Keywords

bronchiolitis - RSV - COVID-19 - epidemiology

• References

• 1 Hall CB, Simőes EA, Anderson LJ. Clinical and epidemiologic features of respiratory syncytial virus. Curr Top Microbiol Immunol 2013; 372: 39-57
• 2 Lozano R, Naghavi M, Foreman K. et al. Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet 2012; 380 (9859): 2095-2128
• 3 Glezen WP, Taber LH, Frank AL, Kasel JA. Risk of primary infection and reinfection with respiratory syncytial virus. Am J Dis Child 1986; 140 (06) 543-546
• 4 Li Y, Wang X, Blau DM. et al; Respiratory Virus Global Epidemiology Network, RESCEU investigators. Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: a systematic analysis. Lancet 2022; 399 (10340): 2047-2064
• 5 Bloom-Feshbach K, Alonso WJ, Charu V. et al. Latitudinal variations in seasonal activity of influenza and respiratory syncytial virus (RSV): a global comparative review. PLoS One 2013; 8 (02) e54445
• 6 Foley DA, Phuong LK, Peplinski J. et al. Examining the interseasonal resurgence of respiratory syncytial virus in Western Australia. Arch Dis Child 2022; 107 (03) e7
• 7 Torres-Fernandez D, Casellas A, Mellado MJ, Calvo C, Bassat Q. Acute bronchiolitis and respiratory syncytial virus seasonal transmission during the COVID-19 pandemic in Spain: a national perspective from the pediatric Spanish Society (AEP). J Clin Virol 2021; 145: 105027
• 8 Fourgeaud J, Toubiana J, Chappuy H. et al. Impact of public health measures on the post-COVID-19 respiratory syncytial virus epidemics in France. Eur J Clin Microbiol Infect Dis 2021; 40 (11) 2389-2395
• 9 Saravanos GL, Hu N, Homaira N. et al. RSV epidemiology in Australia before and during COVID-19. Pediatrics 2022; 149 (02) e2021053537
• 10 Camporesi A, Morello R, Ferro V. et al. Epidemiology, microbiology and severity of bronchiolitis in the first post-lockdown cold season in three different geographical areas in Italy: a prospective, observational study. Children (Basel) 2022; 9 (04) 491
• 11 Agha R, Avner JR. Delayed seasonal RSV surge observed during the COVID-19 pandemic. Pediatrics 2021; 148 (03) e2021052089
• 12 Rodríguez-Grande C, Buenestado-Serrano S, Alcalá L. et al; Gregorio Marañón Microbiology-ID COVID 19 Study Group. SARS-CoV-2 B.1.1.7 decline is not driven by the introduction of a more successful variant. Microbiol Spectr 2021; 9 (03) e0112821
• 13 Ferrés Mataró J, Mangues Bafalluy MA, Farré Riba R, Juliá Brugues A, Bonal de Falgas J. Subcutaneous adrenaline versus inhaled salbutamol in the treatment of childhood asthmatic crisis [in Spanish]. An Esp Pediatr 1987; 27 (01) 37-40
• 14 Tang X, Dai G, Jiang X. et al. Clinical characteristics of pediatric respiratory tract infection and respiratory pathogen isolation during the coronavirus disease 2019 pandemic. Front Pediatr 2022; 9: 759213