ORIGINAL RESEARCH article

Front. Public Health

Sec. Infectious Diseases: Epidemiology and Prevention

Volume 13 - 2025 | doi: 10.3389/fpubh.2025.1606491

Age-period-cohort Analysis of Syphilis epidemics in Eastern China, China, 2005 -2024

Provisionally accepted
Zheyuan  DingZheyuan Ding1Shuangqing  WangShuangqing Wang2Junjie  LiJunjie Li1Haocheng  WuHaocheng Wu1Qinbao  LuQinbao Lu1Xinyi  WangXinyi Wang1Tianyin  FuTianyin Fu1Kui  LiuKui Liu1*Chen  WuChen Wu1
  • 1Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
  • 2Quzhou Center for Disease Control and Prevention, Quzhou, China

The final, formatted version of the article will be published soon.

Background: Syphilis remains one of the serious public health challenges in China and worldwide. This study aims to assess the potential independent risks associated with age, period, and birth cohort for the reported incidence of syphilis in Eastern China.Methods: Data on all syphilis cases from 2005 to 2024 in Zhejiang Province in Eastern China were collected from the China Information System for Disease Control and Prevention. The Age-Period-Cohort (APC) model was used to analyze the effect coefficients, which were then converted into relative risks (RRs).Results: From 2005 to 2024, a total of 617,097 syphilis cases were reported in Zhejiang Province. The reported incidence of syphilis decreased by an average of -3.53% per year across all age groups (95% CI: -4.34%, -2.70%). The age effect showed that the highest reported incidence was among individuals aged 20-24 years, with a relatively high rate also observed in those aged 60 years and above. The period effect indicated that compared with the reference group of 2010-2014 with the highest reported incidence risk, the risk in 2020-2024 was the lowest (RR = 0.48; 95% CI: 0.43, 0.54).The cohort effect shows that the risk decreased in later birth cohorts, with the highest reported incidence risk in the birth cohort of 1960-1964 (RR = 1.30; 95% CI: 1.08, 1.57) and the lowest risk in the birth cohort of 2020-2024 (RR = 0.00; 95% CI: 0.00, 0.18).Conclusions: The reported incidence of syphilis in Zhejiang Province has shown an overall downward trend. The implementation of national syphilis control programs has achieved significant results. There is a need to strengthen the management of late-stage syphilis among the elderly and enhance syphilis prevention and control efforts among adolescents.

Keywords: Syphilis, reported incidence, age-period-cohort model, eastern China, Cohort Effect

Received: 12 Apr 2025; Accepted: 13 Jun 2025.

Copyright: © 2025 Ding, Wang, Li, Wu, Lu, Wang, Fu, Liu and Wu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Kui Liu, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.