Effects of climate parameters in dengue fever incidence in Taiwan - retrospective observation from 1998 to 2010

Abstract

Background: The epidemic patterns of dengue fever associated with climate changes in tropical and subtropical regions have attracted worldwide attention. Temperature, precipitations, relative humidity, and extreme climate events may complicate the epidemic of the disease. Transmitted by Aedes mosquitoes, the epidemic of the disease varied annually and clustered in southern part of Taiwan characterized with subtropical weather. Objective: The goal of this study was to investigate the relationship between climate factors and dengue fever epidemic in all Taiwan area. Methods: We obtained the meteorological data from the Taiwan Central Weather Bureau and used the insurance claims data to identify monthly newly diagnosed dengue fever cases from 1998 to 2010. Multivariable regression analysis was used to measure the association between incident cases of dengue fever and weather conditions in Taiwan including temperature, precipitations and humidity controlling for population density and geographical area. Results: The results showed that dengue fever incidence was positively associated with temperature, precipitations, relative humidity at lagged 1 to 5 months. The most significant associations, based on the value of r, for mean temperature (r = 0.47, p <0.01), precipitation (r = 0.41, p <0.01), and relative humidity (r = -0.32, p <0.001) were found at lags of 3 months, 2 months, and 11 months, respectively. In multiple regression, precipitations and relative humidity showed the significance in whole model (p = 0.001 and p = 0.009), indicating the air water content could be a remark factor in dengue fever occurrence. Conclusion: Ultimately, we have better understanding of the relationship between climate factors and dengue fever occurrence, and humidity and rainfall could be the predictor of dengue fever occurrence in Taiwan.