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Syphilis tests tell if a person has this infection, or if they've had an infection in the past. They look for antibodies to the bacterium, or germ, that causes syphilis. Some tests look for the syphilis germ itself.
Syphilis is a sexually transmitted infection (STI). That means it is spread through sexual contact: vaginal, anal, or oral sex, or sometimes just close physical contact, like foreplay. If you're pregnant and you have syphilis, you can pass the infection to your baby.
These tests are usually blood tests. Depending on your symptoms, you may have more tests done on body fluids or tissue samples.
If a first screening test is positive, the lab will run two more tests to be sure you have a syphilis infection. It can take up to 12 weeks from the time you're exposed to syphilis for blood tests to show the infection.
A syphilis infection can spread through your bloodstream to all parts of your body. Without treatment, syphilis can cause severe heart disease, brain damage, spinal cord damage, blindness, and death. If you're pregnant, your baby could develop congenital syphilis, and other health problems. There is also a risk of your baby dying before they are born (stillbirth).
A test for syphilis is done to:
Screening for syphilis and other sexually transmitted infections is often done for people who engage in sexual behaviours that put them at risk. If you have syphilis, your sex partner or partners should be told, tested, and treated to prevent serious problems and to stop the spread of the disease.
Tell your doctor if you:
If you have syphilis, do not have sex until the test results show that you are no longer infected or until you and your sex partner or partners have completed treatment and the infection has been cured. Your sex partners should be tested and treated as well.
If you think you might have syphilis, do not have sex until testing shows that you are not infected.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results may mean. To help you understand the importance of this test, fill out the medical test information form .
A syphilis test may be done on a sample of blood, sore, skin, or spinal fluid, depending on which type of test is done.
Blood test from a vein
The health professional taking a sample of your blood will:
A sample of fluid or tissue may be taken from an open sore or from a rash that might be caused by syphilis.
A spinal tap (lumbar puncture) is done to collect a spinal fluid sample for syphilis when the infection may have spread to the nervous system ( neurosyphilis).
For a lumbar puncture, a thin needle is inserted into the spinal canal in the lower back. After the needle is in place, a small amount of fluid is removed from the spinal canal. To learn more, see the topic Lumbar Puncture.
The blood sample is taken from a vein in your arm. You may feel nothing at all from the needle, or you may feel a quick sting or pinch. When blood is taken from a vein, an elastic band is wrapped around your upper arm and may feel tight.
You may feel some discomfort when fluid is collected from an open sore. But syphilis sores usually are not very tender or painful.
You may feel some discomfort during a lumbar puncture to collect spinal fluid. To learn more, see the topic Lumbar Puncture.
There is very little chance of a problem from having a blood sample taken from your vein.
There is very little risk of problems from having a sample taken from an open sore, skin rash, or mucous membrane.
There is little risk linked with having a lumbar puncture to obtain a spinal fluid sample. To learn more, see the topic Lumbar Puncture.
Syphilis tests tell if a person has the infection. 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.
No syphilis antibodies are found. This is called a non-reactive 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 indeterminate.
If you've tested positive for syphilis in the past, two of the tests that look for antibodies will likely be positive for life (EIA and TPPA). The RPR test is used to tell if you've been cured. It's also used to tell if you have been infected again and need to be treated again.
The accuracy of testing often depends on the stage of syphilis. Testing may need to be repeated if:
A test for syphilis is based on your risk of infection. You can, and should, still be tested even if:
To learn more about testing for sexually transmitted infections, see:
CitationsPublic Health Agency of Canada (2013). Canadian guidelines on sexually transmitted infections: Specific population—Pregnancy. Public Health Agency of Canada. http://www.phac-aspc.gc.ca/std-mts/sti-its/cgsti-ldcits/section-6-4-eng.php. Accessed October 3, 2014.Other Works ConsultedChernecky CC, Berger BJ (2013). Laboratory Tests and Diagnostic Procedures, 6th ed. St. Louis: Saunders.Pagana KD, Pagana TJ (2014). Mosby's Manual of Diagnostic and Laboratory Tests, 5th ed. St. Louis: Mosby.
Adaptation Date: 3/8/2021
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
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