431. Asymptomatic Latent Syphilis and Stroke in Geriatric Patients; Analysis of Routine Syphilis Tests

Background Increasing incidence of syphilis in the young to middle age population is a concern in Japan. Although stroke is a known complication of syphilis, it is unknown for asymptomatic latent syphilis (ALS). Our aim was to investigate the results of routine syphilis tests to find the association between stroke and ALS in geriatric patients. Methods This retrospective observational study included patients above 65 years of age who underwent the rapid plasma reagin (RPR) and treponema pallidum hemagglutination assay (TPHA) tests (Showa Medical Science, Kanagawa, Japan) as routine evaluation at an institute from August 2014 to February 2019. Asymptomatic patients with positive TPHA were diagnosed with ALS. Clinical data were collected, including the age, gender, history of stroke, underlying diseases, complications (thoracic aortic aneurysm, aortic regurgitation, dementia), habits, indication for syphilis test, and syphilis description in the medical records. Negative TPHA was the exclusion criterion. A multivariate analysis was used to determine the independent risk factors for stroke. All variables with P < 0.1 in the univariate analysis were evaluated using the multivariate model with the level of significance set at P < 0.05. Statistical analyses were performed using R version 3. 3. 1. Results A total of 10,117 geriatric patients underwent the syphilis test in the study period. The TPHA test was positive for 96 patients (0.95%), including 45 (46.9%) men, who were included in the study. The median age was 86 years (range: 65–102). The RPR test was positive for 51 cases (53.1%). The indications for syphilis test were syphilis screening for admission (n = 71), endoscopy (n = 16), health checkup (n = 3), and others (n = 6). No past treatment history for syphilis was found in the medical records. Syphilis descriptions were found for 6 patients (6.25%). One patient had been treated for ALS. A multivariate analysis revealed that positive RPR [odds ratio: 3.39; 95% confidence interval: 1.17 to 9.78; P = 0.0241] was associated with history of stroke. Conclusion For ALS in geriatric patients, positive RPR is associated with history of stroke. Medial evaluation about risk for stroke is necessary for ALS in geriatric patients. Disclosures All authors: No reported disclosures.