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    Syphilis Tests


    Syphilis tests tell if a person has the disease. They look for antibodies to the bacterium, or germ, that causes syphilis. Some tests look for the syphilis germ itself.

    Results are usually available in 7 to 10 days.

    Darkfield microscopic examination

    No syphilis germs are seen.


    Syphilis germs are seen.

    Syphilis tests of blood and spinal fluid

    No syphilis antibodies are found. This is called a nonreactive or negative result.


    Antibodies are found. 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

    Syphilis antibodies are not found. This is called a nonreactive or negative result.


    Antibodies are found. This is called a reactive or positive test.

    The accuracy of testing often depends on the stage of syphilis. Testing may need to be repeated if:

    • Results of the first test are uncertain.
    • You have had repeated exposure to syphilis, such as from repeated unprotected intercourse.

    What Affects the Test

    You may not be able to have the test, or the results may not be helpful, if:

    • You use antibiotics before you have the test.
    • You have a blood transfusion in the weeks before having the test.
    • You have another condition or disease, such as lupus, liver disease, HIV infection, or a tropical bacterial infection called yaws.

    What To Think About

    Test results

    • A reactive or positive test result does not always mean that you have syphilis. Other conditions can cause positive test results. These include injecting illegal drugs, recent vaccinations, endocarditis, autoimmune diseases (such as systemic lupus erythematosus, or SLE), tuberculosis, mononucleosis, leprosy, malaria, hepatitis, Lyme disease, rheumatoid arthritis, and, in rare cases, pregnancy.
    • With treatment, a positive VDRL or RPR test result usually becomes negative. Positive FTA-ABS, MHA-TP, or TPPA tests stay positive for a lifetime, even after syphilis has been cured.
    • In the United States, your health professional must report to the state health department that you have syphilis.

    Syphilis and HIV infection

    • Sores caused by syphilis make it easier to get and spread an HIV infection.
    • People with HIV who have a negative VDRL test should have a second test for syphilis if the infection is suspected.

    To learn more about testing for sexually transmitted infections, see:

    WebMD Medical Reference from Healthwise

    Last Updated: November 14, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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