“…Failure to recognize a prozone effect in maternal serum tested during pregnancy has resulted in failure to diagnose congenital syphilis [247]. Nontreponemal test results may also be falsely negative (i.e., nonreactive) in early (prechancre state) primary syphilis, latent acquired syphilis of long duration, and late congenital syphilis because over the course of time even some untreated patients may revert to seronegative nontreponemal status [198,[317][318][319]. Nontreponemal tests are used primarily for screening (i.e., to establish a "presumptive" diagnosis) and monitoring of therapy [320].…”