The Venereal Disease Research Laboratory (VDRL) test is a blood test used to screen for syphilis, a sexually transmitted infection caused by the bacterium Treponema pallidum. The test measures the antibodies produced by the body in response to antigens produced by cells damaged by the bacteria. The VDRL test is a nontreponemal test, which means it is not specific to syphilis and can produce false-positive results in certain conditions such as HIV/AIDS, Lyme disease, certain types of pneumonia, malaria, and systemic lupus erythematosus.
The VDRL test is usually performed by drawing blood from a vein at the crease of the elbow or the back of the hand. The test does not require fasting or stopping any medications, and there is little risk involved with having blood taken. A negative test result means that no antibodies to syphilis have been seen in the blood sample, while a positive test result means that the person may have syphilis. If the test is positive, the next step is to confirm the results with a more specific syphilis test, such as the fluorescent treponemal antibody absorption (FTA-ABS) test.
The VDRL test is commonly used to screen for syphilis during prenatal care, as well as for people who have signs and symptoms of a sexually transmitted illness (STI) . The tests ability to detect syphilis depends on the stage of the disease, with the test being less sensitive during the earlier and later stages. If a persons doctor suspects that the syphilis infection has spread to their brain, they may choose to test their spinal fluid in addition to their blood.
In summary, the VDRL test is a blood test used to screen for syphilis by measuring the antibodies produced by the body in response to antigens produced by cells damaged by the bacteria. A negative test result means that no antibodies to syphilis have been seen in the blood sample, while a positive test result means that the person may have syphilis. The test is commonly used to screen for syphilis during prenatal care and for people who have signs and symptoms of an STI.
