Revisiting the role of rainfall variability and its interactive effects with the built environment in urban dengue outbreaks. (December 2018)

• Record Type: Journal Article
• Authors: Chen, Tzu-Hsin Karen; Chen, Vivian Yi-Ju; Wen, Tzai-Hung
• Is Part Of: Applied geography. Volume 101(2018)
• Page Start: 14
• Page End: 22
• Publication Date: 2018-12
• Subjects: Rainfall -- Built environment -- Multilevel model -- Dengue -- Taiwan; Geography -- Periodicals; Human geography -- Periodicals; Human ecology -- Periodicals; 910
• DOI: 10.1016/j.apgeog.2018.10.005
• Languages: English
• ISSNs: 0143-6228

Abstract

Abstract: Dengue fever is a rapidly spreading mosquito-borne disease. Previous studies have shown that dengue vector mosquitoes are weather sensitive, and the effect of temperature on dengue transmission has been confirmed. However, associations between rainfall events and dengue incidence are not consistent, and few studies have addressed the roles of the magnitude and frequency of rainfall events in dengue transmission. Therefore, the purpose of this study was to differentiate the long-term and short-term effects of rainfall variation on dengue transmission and to investigate these effects within different socio-ecological contexts in southern Taiwan, which is a high-epidemic tropical region. A negative binomial multilevel model with Gaussian serial correlation was used in this study to investigate the intra- and inter-annual rainfall variability to determine the effects of rainfall on dengue occurrence in the pre-epidemic and epidemic seasons. Our significant results indicate that short-term rainfall and dengue occurrence show a non-linear relationship in which medium rainfall during the dengue season poses the most significant risk. We also found that rainfall effects are interactive to the percentage of old houses. Our results show strong synergistic interactions between low rain frequency and old house percentage, and between cumulative rainfall and old house percentage, contributing to dengue outbreaks. Our findings also differentiate the effects of short-term and long-term rainfall in old built-up environments on dengue occurrence. This implies that during rainy periods, old neighborhoods may require more attention from the public and private sectors to improve environmental quality and promote resident health. Highlights: We addressed the roles of rainfall magnitude and frequency in dengue transmission from long and short-term perspectives. We used a negative binomial multilevel model to differentiate intra- and inter-annual rainfall variability. The effect of short-term rainfall magnitude on dengue outbreaks is non-linear—medium rainfall events pose the highest risk. Old neighborhoods and little rainfall events have synergetic effects on dengue outbreaks. Dengue occurrence is the result of interactions between rainfall variability and built environments.