The effect of climate variables on the risk of dengue incidence in Singapore: A temporal analysis for the period 2000-2012

Abstract

THE EFFECT OF CLIMATE VARIABLES ON THE RISK OF DENGUE INCIDENCE IN SINGAPORE: A TEMPORAL ANALYSIS FOR THE PERIOD 2000-2012 Authors: Kavitha Palaniappan, Santu Ghosh Background: In spite of the multi-pronged dengue control strategy, the dengue epidemic remains a major public health concern in Singapore. The increased frequency of unusual weather conditions may favour the presence of Aedes mosquitoes. Hence there is a need to examine the relationship between climate variables and dengue risk so to assess the impact of the climate change on it in Singapore. Objective: This study examined the effect of seasonal factors and relationship between climate variables and dengue incidence per month in Singapore during 2000-2012 to identify the weather parameters that can predict the risk of the dengue epidemic. Methods: The weekly dengue incidence data were collected from the Ministry of Health Singapore’s weekly epidemiological publications for the period 2000-2012 and were merged with the climate data reported by Changi Meteorological Station. Generalized Linear Model was used with Quasi-Poisson distribution to examine the association. Results: The best fitted model was the one with average monthly temperature, dew point and precipitation, controlled for year. We found 12%(p-value<0.05) and 21%(p-value<0.05) increase in dengue cases per month per 1ºF increase in average monthly temperature and dew point respectively, while an one inch increase of precipitation per month led to 5% increase in dengue cases, but was not statistically significant. Conclusions: The radical changes in the seasonal factors of Singapore during the study period and significant association between climate variables and dengue incidence indicate that the unpredictable dengue cases in Singapore could be the hazardous impacts of climate change. Hence, projected changes in the weather patterns suggest that climate change will have a serious impact on the intensity and magnitude of dengue epidemic in the near future.