The VDRL test is a screening test for syphilis, designed to detect antibodies (proteins) that your body may produce in response to an active infection with the bacteria Treponema pallidum, which causes syphilis. It is commonly used to screen for syphilis, particularly when signs and symptoms of a sexually transmitted infection (STI) are present. The test may also be part of routine prenatal care during pregnancy. The VDRL test is similar to the newer rapid plasma reagin (RPR) test, both of which are used to detect syphilis infection.