Examining the interseasonal resurgence of respiratory syncytial virus in Western Australia

Arch Dis Child. 2022 Mar;107(3):e7. doi: 10.1136/archdischild-2021-322507. Epub 2021 Aug 25.

Abstract

Background: Following a relative absence in winter 2020, a large resurgence of respiratory syncytial virus (RSV) detections occurred during the 2020/2021 summer in Western Australia. This seasonal shift was linked to SARS-CoV-2 public health measures. We examine the epidemiology and RSV testing of respiratory-coded admissions, and compare clinical phenotype of RSV-positive admissions between 2019 and 2020.

Method: At a single tertiary paediatric centre, International Classification of Diseases, 10th edition Australian Modification-coded respiratory admissions longer than 12 hours were combined with laboratory data from 1 January 2019 to 31 December 2020. Data were grouped into bronchiolitis, other acute lower respiratory infection (OALRI) and wheeze, to assess RSV testing practices. For RSV-positive admissions, demographics and clinical features were compared between 2019 and 2020.

Results: RSV-positive admissions peaked in early summer 2020, following an absent winter season. Testing was higher in 2020: bronchiolitis, 94.8% vs 89.2% (p=0.01); OALRI, 88.6% vs 82.6% (p=0.02); and wheeze, 62.8% vs 25.5% (p<0.001). The 2020 peak month, December, contributed almost 75% of RSV-positive admissions, 2.5 times the 2019 peak. The median age in 2020 was twice that observed in 2019 (16.4 vs 8.1 months, p<0.001). The proportion of RSV-positive OALRI admissions was greater in 2020 (32.6% vs 24.9%, p=0.01). There were no clinically meaningful differences in length of stay or disease severity.

Interpretation: The 2020 RSV season was in summer, with a larger than expected peak. There was an increase in RSV-positive non-bronchiolitis admissions, consistent with infection in older RSV-naïve children. This resurgence raises concern for regions experiencing longer and more stringent SARS-CoV-2 public health measures.

Keywords: child health; respiratory medicine; virology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bronchiolitis / epidemiology
  • Bronchiolitis / virology
  • COVID-19 / epidemiology
  • Female
  • Hospitalization
  • Humans
  • Infant
  • Male
  • Pandemics
  • Respiratory Sounds / etiology
  • Respiratory Syncytial Virus Infections / diagnosis
  • Respiratory Syncytial Virus Infections / epidemiology*
  • Respiratory Syncytial Virus, Human
  • Respiratory Tract Infections / epidemiology
  • Respiratory Tract Infections / virology
  • SARS-CoV-2
  • Seasons*
  • Western Australia / epidemiology