British Columbia’s Experience after Implementation of the Treponema pallidum Reverse Algorithm and PCR Detection, 2015 to 2020
Muhammad Morshed, Min-Kuang Lee, Jonathan Laley, Darrel Cook, Annie Mak, Navdeep Chahil, Venessa Ryan, Carolyn A. Montgomery, S Makaroff, Sarah Malleson, Barbra Arnold, Troy Grennan, Jason Wong, Mel Krajden
Abstract
In this study, we summarize the performance characteristics of the algorithm, together with PCR direct detection and epidemiological analysis, and report on syphilis cases identified from 2015 to 2020. This allowed us to paint a complete picture of the outcome of the utilization of the reverse algorithm for diagnosing syphilis cases. The study clearly showed that the reverse algorithm had a low false-positive rate and very few equivocal screening results but did identify previously undiagnosed late latent syphilis cases. PCR was more sensitive than both DF and IF microscopy for direct diagnosis and enabled monitoring for azithromycin resistance.