Objective To analyze the epidemiological characteristics and trends of varicella in Taizhou, Zhejiang Province from 2014 to 2023, and to provide evidence for surveillance, prevention, and control of varicella in Taizhou.

Method Individual case data of varicella reported in Taizhou from 2014 to 2023 were collected and analyzed. Descriptive epidemiological methods were used to analyze the distribution characteristics of varicella, and Joinpoint regression models were applied to assess trends in incidence rates.

Results A total of 29 845 cases of varicella were reported in Taizhou from 2014 to 2023, with an annual incidence rate of 47.65/100 000. A total of 22 varicella-related public health events were recorded, accounting for 13.25% of all reported outbreaks during the same period. The annual reported incidence rates for males and females were 51.49/100 000 and 43.56/100 000, respectively. The average annual incidence rate was significantly higher in males than that in females. The age of onset was mainly from 5 to 20 years old, with a total of 20 382 cases reported, accounting for 68.29% of the total cases. Students constituted the majority of cases (62.15%). A distinct seasonal pattern was observed, with a major incidence peak from November to January of the next year and a secondary peak period from May to June. Varicella cases were reported in all counties and districts. The average annual incidence rates in urban districts, mountainous counties and coastal cities were 53.28/100 000, 50.24/100 000 and 41.46/100 000, respectively. Joinpoint regression identified 2019 as a turning point in the overall incidence trend, dividing the period into two phases, but the changes in trend of the two phases were not statistically different (P>0.05). Age-specific analyses revealed divergent trends: incidence rates among the 1‒ and 5‒year-old groups showed steady declines over the 10-year period (APC=-8.481%, P=0.006; APC=-11.690%, P=0.006). The incidence rate of 10‒year-old group showed a rapid decreasing trend from 2019 to 2023 (APC=-21.670%, P=0.026). In contrast, the 15‒ and 20‒year-old groups showed significant increases during the first phase (APC=20.531%, P=0.001; APC=10.778%, P=0.038).

Conclusion From 2014 to 2023, the reported incidence rate of varicella was higher in males than that in females. The highest average annual incidence rate occurred in the 10‒19-year-old age group, with regional variations observed across different areas. The peak incidence period was from November to January of the following year. The overall incidence of varicella in Taizhou was slightly lower than that of the national average level. However, the number of varicella-related outbreaks reported during the same period remained relatively high, underscoring the need for continued and comprehensive prevention and control measures.