Longitudinal Trend in Hospital-Wide Syphilis Testing and Clinical Characteristics of Syphilis Requiring Treatment

Globally, syphilis cases are rising, and varied symptoms hinder diagnosis, highlighting the role of serological testing. Comprehensive institutional analysis is needed, as many reports are limited. We retrospectively reviewed 23 persons with syphilis treated at Kanazawa University Hospital (January 2007-December 2023). Of 9145 individuals tested for treponemal (chemiluminescent enzyme immunoassay) and nontreponemal (rapid plasma reagin, RPR) antibodies, diagnoses were based on clinical assessment and serology. Data on history, stage, lesions, and treatment were collected. From 2007 to 2023, antibody testing increased, but treated cases stayed stable (0-4/year). Males comprised 60.9% and females 39.1%. In the treated 23 patients, ophthalmology (30.4%) and dermatology (17.4%) accounted for nearly half of test requests, though cases arose across specialties. Early-stage and ocular syphilis each occurred in 34.8%. Uveitis was the most common lesion (26.1%). Treatment included amoxicillin (69.6%) or penicillin (21.7%). At diagnosis, 78.3% were dual-positive and 21.7% treponemal-only positive. Nine patients (64.3%) had a ≥4-fold RPR titer decline (median 143.5 days); no RPR increases suggested treatment failure or reinfection. This study found stable treated numbers, with ocular syphilis and uveitis frequent. In specialized institutions, clinicians should consider syphilis in persons with varied symptoms across departments, ensuring comprehensive testing and appropriate follow-up.