Diagnosing Syphilis with PCR-Based Assessment of Oral Swabs

In a small study, 44% of men with primary, secondary, or early latent syphilis had positive oral swabs detected with quantitative PCR targeting a T. pallidum gene.

While gonorrhea and chlamydia infections are now diagnosed routinely with nucleic acid amplification assays, no such test is available for syphilis. However, asymptomatic oral and anal shedding of Treponema pallidum have recently been described, suggesting that detection at these sites is a useful screening tool. Can such oral shedding be identified during early syphilis? In a study at two U.S. centers from September 2020–March 2022, oral swabs were obtained from 32 men with diagnoses of primary, secondary, or early latent syphilis prior to antimicrobial therapy (29 were living with HIV). Quantitative polymerase chain reaction (qPCR) directed at the T. pallidum gene tp0574 (not present in oral Treponema) was performed.

Swabs were qPCR positi…

Reviewing Author

Neil M. Ampel, MD

Disclosures

Editorial BoardsUpToDate

Leadership Positions in Professional SocietiesCoccidioidomycosis Study Group (Past President, Secretary, Treasurer)

Neil M. Ampel, MD

Disclosures

Editorial BoardsUpToDate

Leadership Positions in Professional SocietiesCoccidioidomycosis Study Group (Past President, Secretary, Treasurer)

Diagnosing Syphilis with PCR-Based Assessment of Oral Swabs

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Reviewing Author