The Venereal Disease Research Laboratory test (VDRL) is a blood test for syphilis that was developed by the eponymous lab.

The VDRL test becomes negative after successful therapy, and can be used to monitor treatment.

Unlike the VDRL test, it is a specific test for syphilis.

Quantitative RPR or VDRL tests should be taken at six, 12 and 24 months after treatment.

• Obtain sample for VDRL test (for syphilis)

The VDRL test is used to screen for syphilis (it has high sensitivity), whereas other, more specific tests are used to diagnose the disease.

However, because of the non specific nature of the VDRL test, occasional biological false positives occur in patients with underlying disease processes other than syphilis.

The laboratory diagnosis of neurosyphilis is problematic as the present CSF VDRL test is positive in only 22% to 69% of patients.

Replacement tests such as the VDRL test and the RPR test, initially based on flocculation techniques (Hinton), have been shown to produce far fewer false positive results.

Serological tests may be non-specific, such as the VDRL test, or specific, such as the TPHA and FTA(abs) tests.

With the exception of ocular tissues, serologic tests currently recommended for blood donors should also be used for the donors of these tissues; however, the result of a VDRL test is not required before transplantation.