| Weather Variability, Tides, and Barmah Forest Virus Disease in the Gladstone Region, Australia Suchithra Naish,1 Wenbiao Hu,1 Neville Nicholls,2 John
S. Mackenzie,3 Anthony J. McMichael,4 Pat Dale,5 and
Shilu Tong1 1School of Public Health, Queensland University of Technology, Queensland,
Australia; 2Bureau of Meteorology Research Centre, Melbourne, Australia; 3Department
of Microbiology and Parasitology, University of Queensland, Queensland, Australia; 4National
Centre for Epidemiology and Population Health, Australian National University,
Canberra, Australia; 5Australian School of Environmental Studies,
Griffith University, Nathan, Queensland, Australia Abstract
In this study we examined the impact of weather variability and tides on the transmission of Barmah Forest virus (BFV) disease and developed a weather-based forecasting model for BFV disease in the Gladstone region, Australia. We used seasonal autoregressive integrated moving-average (SARIMA) models to determine the contribution of weather variables to BFV transmission after the time-series data of response and explanatory variables were made stationary through seasonal differencing. We obtained data on the monthly counts of BFV cases, weather variables (e.g., mean minimum and maximum temperature, total rainfall, and mean relative humidity) , high and low tides, and the population size in the Gladstone region between January 1992 and December 2001 from the Queensland Department of Health, Australian Bureau of Meteorology, Queensland Department of Transport, and Australian Bureau of Statistics, respectively. The SARIMA model shows that the 5-month moving average of minimum temperature (b = 0.15, p-value < 0.001) was statistically significantly and positively associated with BFV disease, whereas high tide in the current month (b = -1.03, p-value = 0.04) was statistically significantly and inversely associated with it. However, no significant association was found for other variables. These results may be applied to forecast the occurrence of BFV disease and to use public health resources in BFV control and prevention. Key words: Barmah Forest virus, control, forecasting, Gladstone region, risk factors, time series modeling. Environ Health Perspect 114:678-683 (2006) . doi:10.1289/ehp.8568 available via http://dx.doi.org/ [Online 15 December 2005]
Address correspondence to S. Tong, School of Public Health, Queensland University of Technology, Kelvin Grove, Brisbane, Queensland 4059, Australia. Telephone: 61-7-3864 9745. Fax: 61-7-3864 3369. E-mail: s.tong@qut.edu.au We thank the Queensland Department of Health, Australian Bureau of Meteorology, Queensland Transport, and the Australian Bureau of Statistics for providing the Barmah Forest virus data, weather, tides, and population data, respectively. S.T. is supported by a National Health and Medical Research Council (NHMRC) research fellowship. This study was partly funded by the NHMRC, Australian Research Council and Queensland University of Technology. The authors declare they have no competing financial interests. Received 8 August 2005 ; accepted 15 December 2005. The full version of this article is available for free in HTML or PDF formats. |
