Background: Dengue has been prevalent in Guangdong Province, China, for more than forty years and has shown an increasing trend over the past decade.
Method: A fine-scale analysis of dengue clusters was conducted. The relationship between virus evolution time and spatial distance was analyzed, and a genetic algorithm was used to quantify the effects of environmental, social, and economic factors on the transmission of dengue.
Results: A retrospective study analyzed 172 confirmed dengue cases (April 2019 to April 2020) at the Seventh Affiliated Hospital of Southern Medical University. Whole-genome sequencing revealed a unique transmission origin in Lishui town, Guangdong Province (99.64% to 100% homology). Regardless of the duration of the outbreak (1, 3, or 6 months), the probability that cases within 5 km belonged to the same transmission chain decreased with distance, with a 60-70% probability observed within 200 m. Population density and income were more influential factors than vegetation and precipitation in terms of virus transmission.
Conclusion: The geographical distance among cases and the population density are crucial for determining dengue transmission during fine-scale outbreaks, highlighting important implications for control and surveillance and informing precise prevention strategies for dengue and other vector-borne viruses in China and tropical regions globally as well.
Clinical trial number: Not applicable.
Keywords: Dengue; Fine-scale analysis; Social factors; Spatial-temporal clustering; Vector control.
© 2026. The Author(s).