Predictors of serological cure after penicillin therapy in HIV-negative patients with early syphilis in Shenzhen, China

Abstract

Background Syphilis is a common infectious disease worldwide. Serological monitoring is important for syphilis management. We currently know little about the characteristics of this seronegative response. The aim of this study was to explore the factors associated with serological cure after treatment of early syphilis. Methods A retrospective cohort study was conducted and the data of patients with early syphilis in a clinic in Shenzhen from 2011 to 2019 were retrieved. Univariable and multiple Cox proportional hazard regression models were utilized to identify factors associated with a serological cure state among syphilis patients with early syphilis two years after treatment. Results A total of 346 (85.9%) syphilis patients achieved serological cure. The multivariate analysis results revealed that having a baseline TRUST titer >1:8 was associated with an increased probability of serological cure, compared with having a baseline TRUST titer ≤1:8 (HR = 1.43, 95% CI = 1.10–1.85, P<0.01); primary syphilis was positively associated with serological cure, compared with participants with latent early syphilis (HR = 1.72, 95% CI = 1.27–2.33, P<0.001). Conclusions Two years after treatment, a higher percentage of early syphilis patients achieved serological cure. The study indicated that the syphilis stage and baseline serum titer were crucial factors associated with serological cure.