Abstract: Objective　To investigate the epidemiological characteristics of dengue fever in Shenzhen City in 2024, so as to provide insights into formulation of the preventive and control measures for dengue fever.  Methods　The epidemiological data of dengue cases reported in Shenzhen City in 2024 were extracted from the China Disease Prevention and Control Information System and field epidemiological survey data of dengue fever in Shenzhen City, and the temporal, regional and population distributions of dengue fever cases, source of acquire dengue virus infections, disease diagnosis and treatment and outbreaks were analyzed. The dengue virus nucleic acid was tested and the serotypes of dengue virus were characterized using real⁃time quantitative reverse transcription PCR (RT⁃qPCR) assay, and the dengue virus gene was sequenced using next⁃generation sequencing (NGS). In addition, the surveillance on the density of Aedes albopictus was performed using Breteau index (BI) and mosquito oviposition index (MOI).  Results　A total of 1 735 dengue fever cases were reported in Shenzhen City in 2024, including 952 local cases and 783 imported cases. Most imported dengue fever cases acquired infections from eight cities of Foshan, Guangzhou, Zhongshan, Jiangmen, Dongguan, Zhaoqing, Huizhou, and Zhuhai in the Pearl River Delta region (664 cases, 84.8% of total imported cases) into Baoan, Longgang, and Nanshan districts. The epidemic exhibited an early onset and rapid progression, peaking during the period between September and November (1 632 cases, 94.1% of total cases), and dengue fever cases were distributed across 73 subdistricts in 10 districts, with most cases reported in densely populated central and western regions. The dengue fever cases had a male⁃to⁃female ratio of 1.9 ∶ 1, and a median age of 37 (21) years, with a higher median age among local cases than among imported cases [40 (20) years vs. 33(15) years; Z = -10.303, P < 0.05]. Housework, unemployment, workers, and business service were predominant occupations (1 405 cases, 81.0% of total cases), and there was a significant difference in the constituent ratio of occupations between local and imported cases ([χ2] = 92.3, P < 0.05). Among the 1 735 dengue fever cases, the median duration from onset to definitive diagnosis was 3.3 (2.9) days, and 1 686 cases (97.2%) were identified in healthcare facilities, with a low rate of hospitalization and isolation seen in 1 701 inpatients with available epidemiological data (485 cases, 28.5% of total inpatients). A total of 29 outbreaks of dengue fever occurred in Shenzhen City across 2024, which primarily in construction sites (27 outbreaks, 93.1% of total). Dengue virus typeⅠwas the dominant serotype causing dengue fever in Shenzhen City in 2024. Sequencing showed that the genomes of dengue virus from multiple dengue fever cases in Shenzhen City shared a high sequence homology with those from cities neighboring Shenzhen City, and there might be intra⁃city transmission of dengue virus among multiple construction sites in Shenzhen City. The Aedes albopictus density was significantly higher in Shenzhen City in 2024 than in 2023, peaking from May to September. The annual MOI values ranged from 0.9 to 14.0, and the BI values ranged from 0.6 to 6.0. Conclusions　The overall epidemic of dengue fever was severe in Shenzhen City in 2024, which was greatly affected by case importation from neighboring cities, construction sites⁃centered local transmission, and the effectives of routine mosquito vector control was not satisfactory. Integrated dengue fever control measures should be implemented, focusing on regional joint prevention and control mechanisms, capacity building for mosquito vector control, addressing challenges in epidemic containment at construction sites, and strengthening case detection and management systems.

Key words: Dengue fever, Aedes albopictus, Epidemiological characteristic, Outbreak, Surveillance, Shenzhen City

摘要： 目的　对2024年深圳市登革热流行特征进行分析，为制定该市登革热防控措施提供科学依据。方法　从中国疾病预防控制信息系统和深圳市登革热现场流行病学调查资料中收集2024年深圳市登革热病例信息，对病例三间分布、感染来源、发病诊疗情况以及疫情暴发情况进行流行病学分析。采用荧光实时定量 PCR法对病例感染的登革病毒进行核酸检测和型别鉴定，并通过二代测序技术进行登革病毒基因测序分析。采用布雷图指数（Breteau index，BI）法和诱蚊诱卵指数（mosquito ovitrap index，MOI）法在深圳市各登革热监测点和疫点开展白纹伊蚊密度监测。结果　2024年深圳市累计报告登革热病例1 735例，其中本地病例952例，输入病例783例。84.8%（664例）的输入病例来自佛山、广州、中山、江门、东莞、肇庆、惠州市和珠海市等8个珠三角地区城市，主要流向宝安、龙岗、南山区等。2024年深圳市登革热疫情呈现发病时间早、传播速度快的特点，高峰期出现在9—11月，期间共报告1 632例，占病例总数的94.1%。疫情波及深圳市10个区73个街道。病例主要分布在人口稠密的中西部区域；男女性别比1.9 ∶ 1，中位年龄为37（21）岁，其中本地病例中位年龄［40（20）岁］大于输入病例［33（15）岁］（Z = -10.303，P < 0.05）；病例职业分布以家务及待业、工人和商业服务居多，共1 405例（占81.0%），本地病例和输入病例职业构成差异有统计学意义（[χ2] = 92.3，P < 0.05）。1 735例登革热病例发病到确诊时间中位数为3.3（2.9）d，以医疗机构发现为主（1 686例，占97.2%）；已上报流行病学调查信息的1 701例病例住院隔离率较低（485例，占28.5%）。全年共暴发登革热疫情29起，发生场所主要为建筑工地（27起，占93.1%）。2024年深圳市登革热病例以感染登革病毒Ⅰ型为主，测序结果显示深圳市多个病例与邻近城市发现的病毒基因组序列同源性较高。2024年深圳市白纹伊蚊密度较2023年明显升高，5—9月为高峰期；全年MOI值为0.9 ~ 14.0，BI值为0.6 ~ 6.0。结论　2024年深圳市登革热疫情整体规模大，受周边城市输入、本地工地疫情影响较大，蚊媒控制效果不佳。应针对区域联防联控、蚊媒控制能力建设、工地疫情防控难点、病例发现与管理等方面落实各项防控措施。

关键词: 登革热, 白纹伊蚊, 流行特征, 暴发, 监测, 深圳市