Treponema pallidum PCR testing for diagnosis of mucocutaneous ulcers suspicious for syphilis.

In individuals with T. pallidum PCR-positive lesions, around one in six in our cohort were negative on standard diagnostic serological tests for syphilis. Treponemal DNA testing is an important addition to serological assays in individuals with mucocutaneous ulceration who are at risk of recent syphilis infection and facilitates early diagnosis and contact tracing.