Epidemic characteristics and influential factors of dengue fever in Wanzhou, Chongqing, 2019.

Objective To analyze the epidemiological characteristics and influential factors of dengue fever(DF), and we provide scientific basis for prevention and control of dengue fever outbreaks. Methods Descriptive epidemiology was used to analyze the data of dengue fever in Wanzhou in 2019, and Microsoft Excel 2007 software was used for data statistics. Results There were 333 cases of dengue fever in Wanzhou in 2019, and the attack rate of DF was 20.68/100 000. There were 4 imported cases and 329 local infections. Epidemic of dengue fever spread to 11 streets and 4 towns in Wanzhou, including 328 cases in urban area (98.49%) and 5 cases in rural area (1.51%). All the 4 imported dengue cases were domestic, including 2 from Yunnan, 1 from Hainan and 1 from Taiwan. Among the local infection cases, except one case of Yubei District infection in Chongqing returned to Wanzhou District for treatment, the other 328 cases were distributed in 11 districts in Wanzhou urban area, belonging to local infection cases. Of the 333 cases, 250 cases were clinically diagnosed and 83 cases were laboratory confirmed, all of which were dengue serotype 1. The time distribution was 2 cases in August, 288 cases in September, 42 cases in October, and 1 case in November. The peak of dengue fever occurred in September. 328 locally infected cases were distributed in 11 districts in the main urban area of Wanzhou, and 5 cases were in rural areas. The top 5 towns and townships with the highest incidence were Zhonggulou Street (155 cases), Pailou Street (93 cases), Gaosuntang Street (29 cases), Taibai Street (16 cases) and Chenjiaba Street (11 cases). The age of patients was from 11 months to 82 years, with an average age of 37.49 years old. Conclusion The epidemic of dengue fever has shown a sharp increase. Wanzhou has opened international flights to Cambodia and Thailand, where dengue fever is more severe, which also has accelerated the movement of people. And the density of Aedes albopictus has not been controlled effectively. Therefore, continuous monitoring of dengue fever, density of Aedes albopictus, real-time analysis and early warning of monitoring results are suggested for departments of government. [ABSTRACT FROM AUTHOR]