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
The accuracy of testing often depends on the
stage of syphilis. Testing may need to be repeated if:
- Results of the first test
- 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
- You have a blood transfusion in the weeks before having the
- You have another condition or disease, such as
HIV infection, or
a tropical bacterial infection called yaws.
What To Think About
- 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,
autoimmune diseases (such as systemic lupus
erythematosus, or SLE),
Lyme disease, rheumatoid arthritis, and, in rare cases, pregnancy.
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: