Epidemiological Trends and Public Health Implications of Dengue Fever in Zhejiang Province, China: A Decadal Analysis from National to Cangnan Perspectives.

Objective: To analyze dengue fever outbreaks in China, Zhejiang Province, and a local region to provide a scientific basis for early warning surveillance and the prevention and control of dengue epidemics. Methods: This retrospective study examines dengue fever data from China and Zhejiang Province over the past decade, including incidence, mortality, seasonal distribution, age characteristics, and regional distribution. Local data from the past decade were also analyzed. Results: Over the last ten years, the average annual incidence rate of dengue fever in China has been 0.7764 per 100,000 individuals, with a mortality rate of 0.000945 per 100,000. In the same period, the incidence rate in Zhejiang Province was 0.4546 per 100,000, with no fatalities reported. Dengue fever cases in both China and Zhejiang Province are primarily seen during the summer and autumn seasons. Between 2014 and 2020, cases were documented across all age groups in China, demonstrating an age-specific pattern in the annual average incidence rate, with rates initially increasing to peak in young adults and subsequently declining with advancing age. The highest rates were noted in the 20-29.9 and 30-39.9 age brackets. With the exception of Tibet, all regions in China have recorded cases, with Guangdong, Yunnan, Fujian and Zhejiang in the southern part of the country being the main high-incidence areas. In Cangnan County, 30 cases of dengue fever were reported over the past decade, predominantly affecting imported cases, males, and young to middle-aged adults. Conclusion: Dengue fever cases are rising in China, particularly in southern regions. 15 to 50 years old people are most affected. There is a pressing need for region-specific strategies to mitigate the impact of dengue fever, particularly in high-incidence areas.