Definition of RPR:

RPR (rapid plasma reagin) is a screening test for syphilis. It looks for antibodies that are present in the blood of people who have the disease.

The test is similar to the venereal disease research laboratory (VDRL) test.

How the test is performed:

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic. An elastic band is placed around the upper arm to apply pressure and cause the vein to swell with blood.

A needle is inserted into the vein, and the blood is collected in an airtight vial or a syringe. During the procedure, the band is removed to restore normal blood flow. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, the area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a small glass tube (pipette), on a slide, onto a test strip, or into a small container. A bandage may be placed on the puncture site if bleeding continues.

How to prepare for the test:

No special preparation is usually needed.

How the test will feel:

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, you may feel some throbbing.

Why the test is performed:

The RPR test can be used to diagnose syphilis. It is used to screen people who have symptoms of sexually transmitted diseases and is routinely used to screen pregnant women for the disease.

Several states also require that couples be screened for syphilis before getting a marriage license.

The test is also used to see how treatment for syphilis is working. After treatment with antibiotics, the levels of syphilis antibodies should fall. These levels can be monitored with another RPR test. Unchanged or rising levels can mean a persistent infection.