Unreliability of current screening tests for syphilis in chronic psychiatric patients

OBJECTIVE: This study examined whether psychiatrists perform adequate diagnostic screening for syphilis in patients with chronic mental illness. METHOD: Two hundred patients with chronic mental illness underwent testing for syphilis with the commonly used RPR test and the microhemagglutination assay for Treponema pallidum (MHA-TP). Sensitivities of the two tests were compared. RESULTS: A substantial number of patients with negative results on RPR tests had reactive MHA- TPs and would have not been identified as having had syphilis with the use of RPR testing alone. CONCLUSIONS: Nontreponemal tests such as the RPR test are less likely than treponemal tests to detect syphilis appropriately in chronically mentally ill patients, and specific treponemal tests such as the MHA-TP should be considered.