The correlation of climate factors on dengue transmission in urban area: Bangkok and Singapore cases

The objective of this study is to find the correlation between climate factors and dengue incidence rate in Bangkok and Singapore during 2009-2015. Spearman's rank correlation tests with time-lag are performed to investigate the overall correlation between dengue incidence rates and climate factors , minimum, mean, and maximum temperatures, DTR, and rainfall. A Linear and Poisson regression analysis was performed. Spearman's rank correlation tests show that in Bangkok monthly rainfall (r=0.451, p<0.001), the number of rainy days (r=0.411, p<0.001) are positive correlation with 2 month lag time. DTR (r=-0.335, p<0.001) is negative correlation with 2 month lag time. Maximum (r=0.256, p<0.001), mean (r=0.304, p<0.001) and minimum (r=0.323, p<0.001) temperature are positive correlation with 4 month lag time. In Singapore, only minimum temperature (r=-0.299, p<0.001) with 1 month lag time is negative correlation and DTR (r=-0.289, p<0.001) with zero month lag time is positive correlation. The rest has no statically significance (p>0.05). This study concluded, climate factors play moderate role in dengue incidence in Bangkok. There is no statistical significance between rainfall and dengue incidence rate and temperature play a marginal role in Singapore.