Abstract:
Objective To analyze the characteristics of dengue fever epidemic in China and provide reference to risk assessment of dengue fever epidemic. Methods The incidence data of dengue fever were obtained from the national notifiable communicable disease reporting information system in China for the analysis of the spatial and time distribution of dengue fever cases. The sources of imported dengue fever cases and the time distributions of the imported and indigenous cases were also summarized. Results As of 31th August in 2017, a total of 1 468 cases of dengue fever were reported nationwide, an increase of 77% compared with the same period in 2016 (831 cases). Among them, 980 were indigenous cases, which mainly distributed in Yunnan (589 cases), Zhejiang (221 cases), Guangdong (111 cases), Shandong (58 cases) and Anhui provinces (1 case).The number of imported cases were 488 and the source countries were Myanmar (137 cases), Malaysia (61 cases), Thailand (54 cases),Vietnam (39 cases) and Sri Lanka (34 cases).The early cases of dengue fever of Yunnan, Guangdong, Zhejiang and Shandong provinces were all imported cases. Local outbreaks were reported in Xishuangbanna, Dehong and Lincang in Yunnan province, Hangzhou in Zhejiang province, Guangzhou in Guangdong province, and even Jining in Shandong province. The Brett index of vector density of Yunnan, Hainan, Fujian, Guangxi, Guangdong and Zhejiang and other provinces at high-risk was greater than the threshold of 5. Conclusion As of 31th August, the dengue fever epidemic was more serious in China compared with the same period in 2016, and the northern province of Shandong was also affected. All the local outbreaks were caused by imported cases. The epidemic peak would occur in September with increased epidemic risk in Zhejiang, Yunnan, Guangdong, Guangxi and Hainan provinces. It is suggested to pay attention to dengue fever prevention and control before the epidemic season, even in northern provinces.