What screening method is recommended for high-risk populations for Syphilis?

The recommended screening method for high-risk populations for syphilis is the Rapid Plasma Reagin (RPR) test. This test is a non-treponemal serological assay that detects nonspecific antibodies that are typically present in the setting of syphilis infection. It is particularly useful as an initial screening tool due to its rapid turnaround time and relatively low cost.

High-risk populations, such as men who have sex with men, individuals with multiple sexual partners, and those who are HIV positive, are often screened for syphilis using the RPR test. If the RPR test yields a positive result, it is usually followed by more specific treponemal tests to confirm the diagnosis of syphilis.

In contrast, complete blood count (CBC) and urinalysis are not specific tests for syphilis and typically do not provide relevant information regarding syphilis infection. X-ray imaging is not used for screening syphilis; instead, it may be utilized for assessing certain complications associated with advanced syphilis, such as osteitis or gummas in late-stage disease. Thus, the RPR test stands out as the appropriate choice for screening high-risk individuals for syphilis.