Abstract：
Dengue fever is a viral illness, mainly transmitted by Aedes aegypti and Aedes albopictus. With climate change and urbanisation, more urbanised areas are becoming suitable for the survival and reproduction of dengue vector, consequently are becoming suitable for dengue transmission in China. Chongqing, a metropolis in southwestern China, has recently been hit by imported and local dengue fever, experiencing its first local outbreak in 2019. However, the genetic evolution dynamics of dengue viruses and the spatiotemporal patterns of imported and local dengue cases have not yet been elucidated. Hence, this study implemented phylogenetic analyses using genomic data of dengue viruses in 2019 and 2023 and a spatiotemporal analysis of dengue cases collected from 2013 to 2022. We sequenced a total of 15 nucleotide sequences of E genes. The dengue viruses formed separate clusters and were genetically related to those from Guangdong Province, China, and countries in Southeast Asia, including Laos, Thailand, Myanmar and Cambodia. Chongqing experienced a dengue outbreak in 2019 when 168 imported and 1,243 local cases were reported, mainly in September and October. Few cases were reported in 2013-2018, and only six were imported from 2020 to 2022 due to the COVID-19 lockdowns. Our findings suggest that dengue prevention in Chongqing should focus on domestic and overseas population mobility, especially in the Yubei and Wanzhou districts, where airports and railway stations are located, and the period between August and October when dengue outbreaks occur in endemic regions. Moreover, continuous vector monitoring should be implemented, especially during August-October, which would be useful for controlling the Aedes mosquitoes. This study is significant for defining Chongqing\'s appropriate dengue prevention and control strategies.
摘要：
登革热是一种病毒性疾病,主要由埃及伊蚊和白纹伊蚊传播。随着气候变化和城市化，越来越多的城市化地区正变得适合登革热媒介的生存和繁殖，因此越来越适合在中国传播登革热。重庆,中国西南部的一个大都市，最近受到输入性和本地登革热的影响，2019年经历首次局部疫情。然而,登革热病毒的遗传进化动态以及输入和本地登革热病例的时空模式尚未阐明。因此，这项研究使用2019年和2023年登革热病毒的基因组数据进行了系统发育分析,并对2013年至2022年收集的登革热病例进行了时空分析.我们对E基因的15个核苷酸序列进行了测序。登革热病毒形成单独的簇，与广东省的登革热病毒具有遗传相关性，中国,东南亚国家，包括老挝,泰国,缅甸和柬埔寨。2019年，重庆经历了登革热疫情，报告了168例输入性病例和1243例本地病例，主要在9月和10月。2013-2018年报告的病例很少，由于COVID-19的封锁，从2020年到2022年只有6例进口。我们的发现表明，重庆市的登革热预防应着眼于国内外人口流动，特别是在渝北和万州区，机场和火车站所在的地方，以及8月至10月期间，登革热在流行地区爆发。此外，应实施持续矢量监测，尤其是在8月至10月期间,这将有助于控制伊蚊。本研究对于明确重庆市适宜的登革热防控策略具有重要意义。
