Association between syphilis seroprevalence and age among blood donors in Southern China: an observational study from 2014 to 2017

Wu, Xiaobing; Guan, Yang; Ye, Jianbin; Fu, Hanlin; Zhang, Chunlai; Lan, Lina; Wu, Fengxin; Tang, Fen; Wang, Feng; Cai, Yumao; Yu, Weiye; Feng, Tiejian

Our study has several limitations. First, limited financial and human resources restricted us in using a population-based design, which is considered as the gold standard in evaluating disease epidemics. 12 The choice of blood donors as population samples may result in potential bias, such as selection bias for age coverage and self-identified health conditions. Second, the syphilis seroprevalence among first-time donors was significantly higher than that among repeat donors. 12, 15 This study did not collect the information of first-time donors and repeat donors, which may lead to underestimation of syphilis seroprevalence. Third, false-negative results attributable to the window period of syphilis infection may result in an underestimation of syphilis seroprevalence. However, the residual risk of syphilis infection is very low according to a residual risk analysis conducted in Shenzhen. 37