关键词: 登革热, 输入病例, 分布, 趋势, 流行特征

Abstract:

Objective: To investigate the epidemiological characteristics of dengue fever in Nantong City, Jiangsu Province, China, so as to provide a reference for formulating appropriate prevention and control strategies. Methods: The data of dengue fever cases in Nantong City in 2014-2022 were collected from the China Information System for Disease Control and Prevention and epidemiological investigation reports, and the descriptive epidemiological method was used to perform statistical analyses of the temporal, regional, and population distribution, imported sources, disease onset, and medical treatment of the cases. ArcGIS 10.8 software was used to visualize the regional distribution of the cases. SPSS 22.0 software was used to perform the Shapiro-Wilk test to investigate the normality of the interval time from disease onset to confirmed diagnosis and the interval time from arriving in Nantong City to confirmed diagnosis. Results: In 2014-2022, a total of 52 dengue fever cases were reported in Nantong City, with a mean annual incidence rate of 0.08/100 000, and the highest incidence rate of 0.51/100 000 was observed in 2019. The peak of dengue fever was observed in June to September, with 37 cases accounting for 71.15%. Cases were reported in all seven counties (cities/districts), among which Haimen District reported 19 cases, accounting for 36.55%. The age group of 40- years showed the highest number of 21 cases, which accounted for 40.38%. The male/female ratio was 9.4∶1. As for occupation, most of the patients were migrant workers, with 30 cases accounting for 57.69%. All cases were imported from abroad, mainly Southeast Asia, with 47 cases accounting for 90.38%. The majority of the cases were firstly diagnosed in tertiary medical institutions, with 28 cases accounting for 53.85%. For these 52 cases, the median time interval from disease onset to confirmed diagnosis was 6.0 days. A total of 20 cases were diagnosed in the viremia stage, accounting for 41.67%. Conclusions: The epidemic situation of dengue fever in Nantong City in 2014-2022 shows obvious imported and seasonal characteristics. It is suggested that inbound individuals from Southeast Asia should be regarded as the key population for quarantine and follow-up observation in June to September each year, and it is also recommended to enhance the surveillance and control of mosquito vectors.

Key words: Dengue fever, Imported case, Distribution, Trend, Epidemiological characteristic