Socioecological Changes and Dengue Fever Transmission in Queensland, Australia: A Spatial Bayesian Approach

Abstract

O-31A5-1 Background/Aims: This study examined the impact of socioecologic factors on the transmission of dengue fever (DF) and assessed the difference in the potential predictors of DF between locally and overseas-acquired cases, Queensland, Australia. Methods: We obtained data from the Queensland Health on numbers of notified DF cases by local government area (LGA) in Queensland for the period 1 January 2002–31 December 2005. The data on weather and socioeconomic index for areas (SEIFA) and overseas visitors were obtained from the Australian Bureau of Meteorology and the Australian Bureau of Statistics. A Bayesian spatial conditional autoregressive (CAR) model was used to quantify the relationship between variation of DF and socioecologic factors and to determine spatial patterns of DF. Results: Our results show that the average increase of locally acquired DF was 6% (95% credible interval [CI]: 2%–11%) and 61% (95% CI: 2%–241%) for a 1-mm increase in average monthly rainfall and a 1°C increase in average monthly maximum temperature between 2002 and 2005, respectively. The average increase of overseas-acquired DF cases was 1% (95% CI: 0%–3%) and 1% (95% CI: 0%–2%) for a 1-mm increase in average rainfall and a 1 unit increase in SEIFA. No significant association between numbers of overseas travellers, SEIFA, and DF was found for locally acquired DF cases. For overseas-acquired cases, DF had no significant associations with temperature and numbers of overseas travellers. Conclusion: The results of this study indicated that socioecological factors may have played a significant role in the transmission of DF. Socioecological drivers of locally and overseas-acquired DF appear to differ in Queensland, Australia.