Prevalence and association of syphilis reactivity in an Asian memory clinic population

Data on the association between syphilis reactivity and dementia in memory clinic patients are scarce. We studied the prevalence of syphilis reactivity and investigated its association with dementia and markers of cerebrovascular disease (CeVD) and neurodegeneration. Data on age, gender, education, brain computed tomography scan findings and syphilis reactivity were obtained from patients who attended the National University Hospital memory clinics (February 2006-February 2016) and subjects from the community. Binary logistic regression models were used to investigate associations between syphilis reactivity and dementia, CeVD and neurodegeneration, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Of 1271 memory clinic patients eligible for the study, 57 (4.5%) were syphilis reactive, with the rate of syphilis reactivity higher in demented (44/745; 5.9%) compared to non-demented (13/526; 2.5%) patients ( p = 0.004) and non-demented community-based (21/872; 2.4%) subjects ( p < 0.001). Binary logistic regression showed a significant association between syphilis reactivity and dementia in memory clinic patients independent of demographic factors (odds ratio: 2.06; 95% CI: 1.02-4.17, p = 0.044). A significant association between syphilis reactivity and dementia was found in memory clinic patients. The mechanism of this association requires further research and may involve neuroinflammation.