Syphilis tests detect antibodies in blood or body fluid or tissue to the bacterium that causes syphilis (Treponema pallidum). Results are usually available in 7 to 10 days.
Darkfield microscopic examination
No syphilis bacteria are seen.
Syphilis bacteria are seen.
Syphilis tests of blood and spinal fluid
No antibodies to syphilis are present. This is called a nonreactive or negative result.
Antibodies to syphilis bacteria are present. This is called a reactive or positive test.
A result that is not clearly normal or abnormal is called inconclusive or equivocal.
Venereal disease research laboratory (VDRL) and rapid plasma reagin (RPR) tests
The antibody to the syphilis bacteria (reagin) is not present. This is called a nonreactive or negative result.
The antibody reagin is present. This is called a reactive or positive test.
The accuracy of testing often depends upon the stage of syphilis. Syphilis testing may need to be repeated if initial results are uncertain or if you have had repeated exposure to syphilis, such as from repeated unprotected intercourse.