A 22-year-old patient presents with a genital ulcer suspicious for syphilis. Which is the most appropriate initial serologic screening test?
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Correct answer: VDRL or RPR
Nontreponemal serologic tests (VDRL or RPR) are the standard initial screening tests for syphilis; a reactive result is then confirmed with a treponemal test such as FTA-ABS. Dark-field microscopy and PCR are direct-detection methods rather than serologic screens, and FTA-ABS is a confirmatory treponemal test, not an initial screen.
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