title: Did socio-ecological factors drive the spatiotemporal patterns of pandemic influenza A (H1N1)?
abstract: BACKGROUND
  Pandemic influenza A (H1N1) has a significant public health impact. This study aimed to examine the effect of socio-ecological factors on the transmission of H1N1 in Brisbane, Australia.
  
  
  METHODS
  We obtained data from Queensland Health on numbers of laboratory-confirmed daily H1N1 in Brisbane by statistical local areas (SLA) in 2009. Data on weather and socio-economic index were obtained from the Australian Bureau of Meteorology and the Australian Bureau of Statistics, respectively. A Bayesian spatial conditional autoregressive (CAR) model was used to quantify the relationship between variation of H1N1 and independent factors and to determine its spatiotemporal patterns.
  
  
  RESULTS
  Our results show that average increase in weekly H1N1 cases were 45.04% (95% credible interval (CrI): 42.63-47.43%) and 23.20% (95% CrI: 16.10-32.67%), for a 1 °C decrease in average weekly maximum temperature at a lag of one week and a 10mm decrease in average weekly rainfall at a lag of one week, respectively. An interactive effect between temperature and rainfall on H1N1 incidence was found (changes: 0.71%; 95% CrI: 0.48-0.98%). The auto-regression term was significantly associated with H1N1 transmission (changes: 2.5%; 95% CrI: 1.39-3.72). No significant association between socio-economic indexes for areas (SEIFA) and H1N1 was observed at SLA level.
  
  
  CONCLUSIONS
  Our results demonstrate that average weekly temperature at lag of one week and rainfall at lag of one week were substantially associated with H1N1 incidence at a SLA level. The ecological factors seemed to have played an important role in H1N1 transmission cycles in Brisbane, Australia.
authors.affiliation: School of Population Health, The University of Queensland, Australia. w.hu@sph.uq.edu.au
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Hu
authors.forename: Gail
authors.initials: G
authors.lastname: Williams
authors.forename: Hai
authors.initials: H
authors.lastname: Phung
authors.forename: Frances
authors.initials: F
authors.lastname: Birrell
authors.forename: Shilu
authors.initials: S
authors.lastname: Tong
authors.forename: Kerrie
authors.initials: K
authors.lastname: Mengersen
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Huang
authors.forename: Archie
authors.initials: A
authors.lastname: Clements
mesh_terms: D004463:Ecology; D006801:Humans; D015994:Incidence; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology*; D058873:Pandemics / Q000706:statistics & numerical data*; D011793:Queensland / Q000453:epidemiology; D013696:Temperature; D014887:Weather