Air pollution, temperature and pediatric influenza in Brisbane, Australia

Abstract

Previous studies have demonstrated the importance of weather variables in influencing the incidence of influenza. However, the role of air pollution is often ignored in identifying the environmental drivers of influenza. This research aims to examine the impacts of air pollutants and temperature on the incidence of pediatric influenza in Brisbane, Australia. Lab-confirmed daily data on influenza counts among children aged 0-14years in Brisbane from 2001 January 1st to 2008 December 31st were retrieved from Queensland Health. Daily data on maximum and minimum temperatures for the same period were supplied by the Australian Bureau of Meteorology. Winter was chosen as the main study season due to it having the highest pediatric influenza incidence. Four Poisson log-linear regression models, with daily pediatric seasonal influenza counts as the outcome, were used to examine the impacts of air pollutants (i.e., ozone (O3), particulate matter≤10μm (PM10) and nitrogen dioxide (NO2)) and temperature (using a moving average of ten days for these variables) on pediatric influenza. The results show that mean temperature (Relative risk (RR): 0.86; 95% Confidence Interval (CI): 0.82-0.89) was negatively associated with pediatric seasonal influenza in Brisbane, and high concentrations of O3 (RR: 1.28; 95% CI: 1.25-1.31) and PM10 (RR: 1.11; 95% CI: 1.10-1.13) were associated with more pediatric influenza cases. There was a significant interaction effect (RR: 0.94; 95% CI: 0.93-0.95) between PM10 and mean temperature on pediatric influenza. Adding the interaction term between mean temperature and PM10 substantially improved the model fit. This study provides evidence that PM10 needs to be taken into account when evaluating the temperature-influenza relationship. O3 was also an important predictor, independent of temperature.

Geogenic PM10 exposure exacerbates responses to influenza infection

“…Exposure to geogenic PM has been linked to exacerbations of respiratory infections (Lin et al, 2005), including influenza (Xu et al, 2013). These studies have, however, been mostly restricted to cross-sectional epidemiological studies or anecdotal observations, and the specific effects of this prevalent environmental exposure have not yet been fully elucidated.…”

“…Ambient PM 10 concentrations have been associated epidemiologically with increased hospitalisations for respiratory diseases, including lower respiratory tract infections (Lin et al, 2005;Xu et al, 2013).…”

Haze is an important medium for the spread of rotavirus

“…Moreover, this impact was characterized by an evident dosage effect, a lag effect and a cumulative effect. Many studies showed that air pollution could cause a high incidence of respiratory disease (Gordon et al, 2014;Liang et al, 2014;Xu et al, 2013), but the manner in which it impacts diseases of the digestive tract with the hand-mouth approach as the primary route of transmission is unknown. The research team led by Professor Jiang from Peking University described one possibility in their latest study.…”

Extreme temperatures and paediatric emergency department admissions

“…Low temperatures assist survival of bacteria in water droplets 53. Furthermore, low temperatures may increase the incidence of paediatric influenza, and consequently, increase paediatric respiratory diseases 54. Results from the adult population suggest that in cold temperatures respiratory tract infections may occur through either inhalation of cold air (eg, the temperature of the respiratory surface becomes optimal for virus transmission and replication), cooling of the body surface or through cold stress, which causes pathophysiological responses that may contribute to increased susceptibility to these infections.…”