Evaluating the MedMira Multiplo® Complete Syphilis (TP/nTP) antibody test in a sexually transmitted infection clinic in Ottawa, Canada: increased rapid diagnosis and improved antibiotic stewardship

Abstract

Abstract Background Syphilis now affects every population and serology is the mainstay of diagnosis. The issue is that serology has a turnaround time of several days. One solution is point-of-care tests (POCTs), which can provide results in minutes. We consequently evaluated the MedMira Multiplo® Complete Syphilis Test in an STI clinic in Ottawa, Canada. Methods Anyone 16 + years old who consented and was undergoing syphilis testing at our clinic was eligible. Those who enrolled completed the POCT and saw a clinician to review their result. We calculated sensitivities and specificities for the POCT, compared to serology and diagnosis. Results From August 2024 to May 2025, we performed 622 syphilis POCTs on 600 participants. Compared to serology when chemiluminescent microparticle immunoassay (CMIA) and Treponema pallidum particle agglutination (TP.PA) tests were reactive, the POCT treponemal (TP) test had a sensitivity of 90.1% and specificity of 97.9%. Compared to any dilution of rapid plasma reagin (RPR), the POCT non-treponemal (nTP) test had a sensitivity of 82.5% and specificity of 99.1%. When we stratified POCT nTP results based on RPR titers, the POCT nTP had a sensitivity of 94.1% for RPR dilutions ≥ 1:8. Compared to serology, the POCT identified 91.4% of new syphilis infections and 97% of infectious syphilis. Conclusions POCTs informed clinical syphilis management. While most research has focused on how POCTs can facilitate treatment, in our study, there was a second major utility: to withhold antibiotics when recommended as empiric treatment but when the patient does not have active syphilis. Future research on syphilis POCTs should focus on their abilities to rule in and rule out infections. Trial registration NCT06586905 (Registered Sept 4, 2024).