建立以氣候資訊為基礎的台灣登革流行預測模式：1998-2007年登革流行病學和氣象學因子之時序分析

Abstract

Travelers who acquire dengue infection are often routes for virus transmission to other regions. Nevertheless, the interplay between infected travelers, climate, vectors, and indigenous dengue incidence remains unclear. The role of foreign-origin cases on local dengue epidemics has thus been largely neglected by research. This study investigated the effect of both imported dengue and local meteorological factors on the occurrence of indigenous dengue in Taiwan. Using logistic and Poisson regression models, we analyzed bi-weekly, laboratory-confirmed dengue cases at their onset dates of illness from 1998 to 2007 to identify correlations between indigenous dengue and imported dengue cases (in the context of local meteorological factors) across different time lags. Our results revealed that the occurrence of indigenous dengue was significantly correlated with temporally-lagged cases of imported dengue (2-14 weeks), higher temperatures (6-14 weeks), and lower relative humidity (6-20 weeks). In addition, imported and indigenous dengue cases had a significant quantitative relationship in the onset of local epidemics. However, this relationship became less significant once indigenous epidemics progressed past the initial stage. Polytomous Logistic regression model with relevant meteorological variables stepwise selected were able to fitting the value of Dengue Risk Index (DRI) in both Taiwan and Thailand. The Spearman correlation between observed DRI and model-expected DRI ranged from 0.71 to 0.86 in Taiwan and from 0.66 to 0.77 in Thailand, respectively. These findings imply that imported dengue cases are able to initiate indigenous epidemics when appropriate weather conditions are present. Early detection and case management of imported cases through rapid diagnosis may avert large-scale epidemics of dengue/dengue hemorrhagic fever. The potential application of DRI with meteorological modeling in both Taiwan and Thailand demonstrated that its feasibility to be extended to other countries for the current important issue on global warming and dengue. The deployment of an early-warning surveillance system, with the capacity to integrate meteorological data, will be an invaluable tool for successful prevention and control of dengue, particularly in non-endemic countries.