Characterization of dengue epidemics in mainland China over the past decade.

INTRODUCTION Dengue is an important public health concern in developing countries. As it is increasingly serious in mainland China, its spatiotemporal variations in this region must be further understood. METHODOLOGY On the basis of the data on dengue cases in 2004-2013 collected from the China Information System for Disease Control and Prevention, examinations of spatiotemporal variations of local, imported, and total dengue cases were conducted to characterize this epidemic at the city scale in China. RESULTS Local cases in September and October accounted for more than half of the total cases in each year. The cities with more than 50 accumulative local cases were mainly distributed along the southeast coastal areas and southwest border regions of China. In 2004-2013, local dengue transmission (indicated by the number of local cases and the locally infected cities) increased yearly and was closely associated with epidemics (represented by the amount of imported cases and the cities with imported cases). At the city level, local transmission tended to be spatially clustered in the Zhejiang-Fujian coastal area, the Pearl River Delta, and Yunnan-Burma border region, especially in 2005, 2010, 2012, and 2013. CONCLUSIONS The results showed that China's local dengue transmission is spatially and temporally featured, and that the prevalence of this epidemic is mostly related to imported cases from overseas epidemic areas. This study provides useful support for hygiene authorities of central and local governments to take effective measures to prevent and control this disease.