VDRL False Positive Causes

Primary Causes of False-Positive VDRL Results

Biological false-positive (BFP) VDRL reactions occur in approximately 0.24-0.92% of the general population, with significantly higher rates in specific populations including women, elderly patients, HIV-positive individuals, pregnant women, and those with autoimmune diseases 1
Pregnancy is associated with BFP reactions in 0.6-0.72% of pregnant women 1
Autoimmune diseases, particularly systemic lupus erythematosus (SLE), are associated with BFP reactions in 11.8% of SLE patients 1
Other infectious and medical conditions, including malaria, hepatitis C virus infection, leprosy, and other treponemal diseases (non-syphilis treponematoses), are associated with increased BFP rates 1
Illicit drug use is associated with increased BFP rates 1
Vaccines can trigger transient BFP reactions 1

The Centers for Disease Control and Prevention recommends that all positive nontreponemal tests must be confirmed with treponemal-specific tests (FTA-ABS, TPPA, or TP-PA) to distinguish true syphilis infection from BFP reactions 2