The venereal disease research laboratory (VDRL) test is designed to assess whether or not you have syphilis, a sexually transmitted infection (STI). Syphilis is caused by the bacteria Treponema pallidum. The bacteria infects by penetrating into the lining of the mouth or genital area. That means it is spread through sexual contact of vaginal, anal, or oral sex.
The VDRL test's ability to detect syphilis depends on the stage of the disease. The test's sensitivity to detect syphilis nears 100% during the middle stages; it is less sensitive during the earlier and later stages.
The test is most often done using a blood sample. It can also be done using a sample of spinal fluid.
A negative test is normal. It means that no antibodies to syphilis have been seen in blood sample.
The screening test is most likely to be positive in the secondary and latent stages of syphilis. This test may give a false negative result during early and late stage syphilis. This test must be confirmed with another blood test to make the diagnosis of syphilis.
Abnormal Results
A positive test result may mean you have syphilis. If the test is positive, the next step is to confirm the results with an FTA ABS test, which is a more specific syphilis test.
Some conditions may cause a false positive test, including:
HIV
Lyme disease
Certain types of pneumonia
Malaria
Systemic lupus erythematosus
The body does not always produce antibodies specifically in response to the syphilis bacteria, so this test is not always accurate.
