Objective To investigate the epidemiological characteristics and effectiveness of emergency responses to epidemic foci in Guangzhou City in 2024, so as to optimization of the dengue fever control strategy in Guangzhou City. Methods All data pertaining to dengue fever cases in Guangzhou City in 2024 were collected from the National Notifiable Infectious Disease Surveillance Information Reporting System. The temporal, spatial and population distributions of dengue fever cases and sources of infections were descriptively analyzed, and the effectiveness of emergency responses to epidemic foci of dengue fever was evaluated through standard space index (SSI), the interval from disease onset to case reporting and the percentage of isolation in hospital. Results A total of 3 656 dengue fever cases were reported in Guangzhou City in 2024, including 3 102 local cases and 554 imported cases. Of all cases, 67.86% (2 481 cases) occurred at ages of 20 to 59 years, and the three most common occupations included housework/unemployment (793 cases, 21.69%), business servants (744 cases, 20.35%) and retirees (669 cases, 18.30%). The peak of dengue fever epidemics was concentrated during the period from the 39th to the 45th weeks in 2024, when a total of 2 317 local cases were reported, accounting for 74.69% of all local cases in 2024. Dengue fever cases were reported across all 11 districts in Guangzhou City in 2024, with local cases concentrated in Baiyun District (754 cases, 24.31%), Liwan District (398 cases, 12.83%), Panyu District (365 cases, 11.77%), Haizhu District (332 cases, 10.70%) and Tianhe District (328 cases, 10.57%). Imported dengue fever cases were predominantly domestically imported (492 cases, 88.81%), with the majority imported from Foshan City (377 cases), and overseas imported cases were predominantly imported from southeastern Asian countries. The mean proportion of case isolation in hospital was 9.16% (284/3 102), and the mean interval from disease onset to case reporting was (3.99 ± 2.70) days, while the percentages of mosquito density meeting the required standard were 61.68% (462/ 749) and 66.32% (126/190) on the 4th and 7th day of emergency responses to epidemic foci, respectively. Conclusions The prevention and control cycle of dengue fever in Guangzhou in 2024 took longer than in previous years, with a larger scale of the epidemic. Although some progress has been made in epidemic management, there are still problems such as unsustainable mosquito vector control and low hospitalization isolation rates for cases. Further optimization of control measures in mosquito vector control, case monitoring and management is required to improve the effectiveness of dengue fever control measures.

Objective: To analyze the epidemiological characteristics of dengue fever outbreaks in schools from Guangzhou in 2024, so as to provide a reference for formulating targeted prevention and control policies and measures. Methods: By using the National Infectious Disease Surveillance Information Reporting Management System to obtain information on dengue fever cases in Guangzhou from January 1st to December 31st, 2024. Descriptive data analysis was conducted on the temporal distribution, regional distribution, and school distribution of dengue fever outbreaks in schools. A mediation effect model was used to analyze the mediating effect of the time between onset and reporting between the type of school and the occurrence of recurrent cases. Results: In 2024,12.41% (385 cases) of dengue fever cases in Guangzhou involved schools, with 300 schools affected. Among these, 16 schools (5.33%) reported cluster outbreaks, and 24 schools (8.00%) reported secondary cases. The first dengue case at the school was reported at 26 July and the last case was reported at 4 December, the peak reporting period for cases was October 7 to November 3. The incidence of secondary cases in schools in central urban areas (5.19%) was lower than that in suburban schools ( 17.39 %), and the difference was statistically significant ( χ 2=9.15, P <0.01). The time from onset to reporting partially mediated the relationship between school type and the occurrence of recurrent cases ( β=0.23, P <0.05), accounting for 21.50% of the total effect. Conclusions Dengue fever is a key infectious disease facing schools in Guangzhou during summer and autumn. Surveillance of dengue fever outbreaks in schools should be strengthened during the peak season to reduce the risk of cluster outbreaks and the occurrence of secondary cases.