Sexually Transmitted Disease by Lucinete Messina

The Venereal Disease Research Laboratory (VDRL) is a test to detect patients who have had syphilis, a sexually transmitted disease.

When the test is negative (non-reactive), it usually indicates that the patient never had contact with the syphilis bacterium, Treponema pallidum, or that, having already had the patient come in contact with the bacteria, the organism or treatment was sufficient To delete it.

However, the patient may have syphilis and the negative test is called the prozone effect, which occurs when there is a high number of antibodies produced by the organism during the latent or secondary stage of the disease.


When VDRL is positive (reagent), usually the result is shown in titers (1/2, 1/8, 1/64, 1/128, etc.), which reflects the amount of treponemal antigens present in the patient's blood The greater the denominator, the greater the amount of circulating antigens).

Sometimes the VDRL is positive, but the patient did not have contact with the treponema, it is the so-called false positive result, which can occur in some conditions, such as: infectious mononucleosis, systemic lupus erythematosus, hepatitis A, leprosy, malaria and occasionally, Until the pregnancy.

Since VDRL is not a very specific test for the diagnosis of syphilis, it is advisable to analyze it together with the history and clinical examination and the collection of specific treponemal test, such as FTA-ABS or TPHA, which may be positive or negative. Once the patient has had contact with the treponema, the test will remain positive for the rest of the life, regardless of the treatment.

VDRL collection, associated with a specific treponemal test, is part of the prenatal exams because congenital syphilis can cause several damages to the baby.

If you have a positive VDRL, you should seek an infectious or dermatologist or gynecologist for a better evaluation.