The influence of air quality and meteorological variations on influenza A and B virus infections in a paediatric population in Singapore

Environ Res. 2023 Jan 1;216(Pt 1):114453. doi: 10.1016/j.envres.2022.114453. Epub 2022 Sep 29.

Abstract

Introduction: Influenza is an important cause of paediatric illness across the globe. However, information about the relationships between air pollution, meteorological variability and paediatric influenza A and B infections in tropical settings is limited.

Methods: We analysed all daily reports of influenza A and B infections in children <5 years old obtained from the largest specialist women and children's hospital in Singapore. In separate negative binomial regression models, we assessed the dependence of paediatric influenza A and B infections on air quality and meteorological variability, using multivariable fractional polynomial modelling and adjusting for time-varying confounders.

Results: Approximately 80% of 7329 laboratory-confirmed reports were caused by influenza A. We observed positive associations between sulphur dioxide (SO2) exposure and the subsequent risk of infection with both influenza types. We observed evidence of a harvesting effect of SO2 on Influenza A but not Influenza B. Ambient temperature was associated with a decline in influenza A reports (Relative Risk at lag 5 [RRlag5]: 0.949, 95% CI: 0.916-0.983). Rainfall was positively associated with a subsequent increase in influenza A reports (RRlag3: 1.044, 95% CI: 1.017-1.071). Nitrogen dioxide (NO2) concentration was positively associated with influenza B reports (RRlag5: 1.015, 95% CI: 1.005-1.025). There was a non-linear association between CO and influenza B reports. Absolute humidity increased the ensuing risk of influenza B (RRlag5: 4.799, 95% CI: 2.277-10.118). Influenza A and B infections displayed dissimilar but predictable within-year seasonal patterns.

Conclusions: We observed different independent associations between air quality and meteorological variability with paediatric influenza A and B infections. Anticipated seasonal infection peaks and variations in air quality and meteorological parameters can inform the timing of community measures aimed at reducing influenza infection risk.

Keywords: Air pollution; Climate variability; Harvesting effect; Influenza; Paediatric; Singapore.

MeSH terms

  • Air Pollutants* / analysis
  • Air Pollution* / analysis
  • Child
  • Child, Preschool
  • Female
  • Herpesviridae Infections*
  • Humans
  • Influenza, Human* / epidemiology
  • Nitrogen Dioxide / analysis
  • Singapore / epidemiology

Substances

  • Air Pollutants
  • Nitrogen Dioxide