Syphilis infections (Treponema pallidum) continue to be reported at a high rate, both nationally as well as in Spokane County. Unless a person is symptomatic with primary lesions present on exam, syphilis must be confirmed through serologic testing. Unfortunately, there is no singular diagnostic test available for syphilis. Instead, we rely on multiple serologic tests in combination to confirm a syphilis diagnosis. Historically, two testing algorithms have been used.