Dengue
Version: November 2025
Introduction
Dengue is a mosquito-borne viral infection caused by the dengue virus, which belongs to the Flaviviridae family. It is transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes. Dengue is prevalent in tropical and subtropical regions worldwide, affecting millions annually. Symptoms typically include high fever, severe headache, joint and muscle pain, rash, and mild bleeding. In severe cases, dengue hemorrhagic fever or dengue shock syndrome may occur, leading to potential fatalities. There is no specific treatment for dengue, but early detection and supportive care can significantly reduce death rates. Prevention relies on mosquito control and vaccination.
Highlights
- Dengue incidence peaked in October 2024, showing the highest number of cases (11,083) across the documented years, with no reported deaths. This signals increased spread during warmer seasons.
- 2023 marked another significant surge, particularly between July and October, where case numbers were consistently high, but there was only one associated death.
- Recent data for 2025 indicates an overall decline in cases from October (3,727) to November (849), suggesting a potential seasonal pattern in diffusion.
- While mortality remains low with isolated deaths, the consistent surge in cases annually underscores the need for enhanced preventive measures to manage transmission effectively.
Analysis
Cases Analysis
The Dengue case data in mainland China from November 2015 to November 2025 highlights distinct seasonal trends, with significant case surges typically occurring from August to October each year. Notably, cases spike during these months, peaking in years like 2019 and 2024, when September alone recorded over 8000 and 4800 cases respectively. These trends point to environmental or climatic factors influencing the increased transmission during these months, likely linked to favorable conditions for mosquito vectors.
Mortality across these years remains low, usually zero, with occasional peaks like October 2019 reporting two deaths. This low mortality rate may suggest effective healthcare interventions and public health measures in mitigating severe outcomes, despite the rise in cases.
Between January and April, case numbers generally drop, indicating lower transmission rates during cooler months, which are less conducive to mosquito activity. Comparatively lower case numbers in the years 2020-2022 suggest variability, potentially due to changes in vector control and public health initiatives. The resurgence of cases in subsequent years underscores the persistent and unpredictable nature of Dengue, suggesting an ongoing need for vigilant disease monitoring and response efforts to manage and mitigate outbreaks effectively.
Deaths Analysis
The analysis of dengue-related deaths on the Chinese mainland from 2015 to 2025 shows a remarkably low number of fatalities compared to the fluctuating number of cases. Across this decade, only seven deaths were recorded, indicating a sporadic occurrence of fatalities amidst varied case numbers. The first death was noted in February 2016, during a month with 45 reported cases, suggesting an initial case fatality rate of 2.22%. Subsequent deaths occurred in October and December 2017, October and November 2019, and September 2023, with no further fatalities post-September 2023.
Dengue case numbers varied significantly, peaking in warmer months like August to October. Despite high case counts in years such as 2019 and 2024, deaths remained low, suggesting effective clinical management, vector control, and possibly less virulent strains. Improved surveillance, early diagnosis, and healthcare accessibility likely contributed to the absence of fatalities from 2024 onwards, even as cases rose. This suggests that, while the disease burden is substantial in terms of case numbers, public health strategies have effectively mitigated severe disease outcomes. The low mortality rate highlights advancements in medical interventions and public health measures that prevent significant loss of life, reflecting successful handling of the disease despite its presence across numerous cases.