Table 1.

Diagnostic tests for syphilis

Approach	Method	Use	Features
Direct detection	Dark ground microscopy PCR		Require exudates and fluids from lesions PCR improving diagnostic thresholds
Treponemal tests	EIA TPHA/TPPA Western blot (IgG or IgM)	Screening	Highly sensitive Do not correlate with disease activity
Non-treponemal tests (against anti-cardiolipin antibodies)	VDRL RPR	Monitor treatment response Qualitative titre	Correlate with disease activity and treatment response Risk of false positive results

EIA enzyme immunoassay, IgG immunoglobulin G, IgM immunoglobulin M, PCR polymerase chain reaction, TPHA Treponema pallidum haemagglutination assay, TPPA Treponema pallidum particle agglutination assay, RPR rapid plasma reagin, VDRL venereal disease research laboratory