Quick Facts
- Sample: Blood draw from arm
- Fasting: Not required
- Turn-around: 1–2 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Confidential screening - Get tested privately without needing a doctor's visit
- Rapid detection - Identifies syphilis antibodies before symptoms may appear
- Treatment monitoring - Tracks your response to syphilis treatment with titer measurements
- Cost-effective - Affordable screening option available at over 2,000 locations
- Comprehensive results - Includes physician review and secure online access
- No appointment needed - Walk-in testing available at most locations
Who Is This Test For?
- Sexually active individuals seeking routine STI screening
- People with multiple sexual partners or high-risk behaviors
- Anyone experiencing syphilis symptoms (sores, rash, swollen lymph nodes)
- Individuals monitoring syphilis treatment progress
- Those with partners diagnosed with syphilis or other STIs
- People with substance use history or unstable housing situations
How It Works – Just 3 Steps
- Visit a lab location - No appointment required at most walk-in facilities
- Provide blood sample - Quick blood draw from your arm, no special preparation
- Access secure results - Get results online within 1-2 days
FAQ
What does the RPR test detect? The test identifies antibodies your immune system produces in response to syphilis infection.
Can other conditions cause false positives? Yes, autoimmune diseases, pregnancy, tuberculosis, and recent vaccinations may cause false-positive results (UCSF Health 2024).
Do I need to fast before this test? No fasting is required, and you can take medications normally before testing.
What happens if my test is positive? Positive results require confirmatory testing with treponemal-specific tests like FTA-ABS (CDC 2024).
How accurate is the RPR test? The test shows nearly 100% sensitivity during secondary and latent syphilis stages (Mayo Clinic 2024).
Should I tell my sexual partners about testing? Yes, sexual partners should be notified and tested if you receive positive results.
More Details
What is the purpose of this test?
The RPR (Rapid Plasma Reagin) test screens for syphilis by detecting non-specific antibodies produced when your immune system responds to Treponema pallidum, the bacterium causing syphilis (CDC 2024). Unlike tests that look for the bacteria directly, RPR identifies antibodies that react to substances released by cells damaged by the infection. This makes it an excellent initial screening tool and treatment monitoring test.
The test uses a flocculation method where antibodies, if present, cause visible clumping of charcoal particles on a testing card (Mayo Clinic 2024). RPR serves dual purposes: detecting new infections and tracking treatment response through quantitative titer measurements.
Who would benefit from this test?
This test is particularly valuable given that syphilis cases reached epidemic proportions with over 202,000 cases reported in 2022 - an 80% increase since 2018 (CDC 2024). Anyone sexually active should consider RPR testing, especially those with multiple partners, substance use history, or high-risk behaviors.
Pregnant women require universal syphilis screening to prevent congenital syphilis, which increased 740% over the past decade (American Academy of Pediatrics 2024). The disease has expanded beyond traditional high-risk groups to include heterosexual men and women, making routine screening essential for comprehensive sexual health.
When should I order an RPR testing?
Get tested if you experience syphilis symptoms including painless sores, skin rashes (especially on palms and soles), swollen lymph nodes, fever, or fatigue (Mayo Clinic 2024). Order testing before starting new sexual relationships, during pregnancy, or annually if sexually active with multiple partners.
Consider immediate testing if sexual partners have been diagnosed with syphilis or other STIs. Many syphilis infections are asymptomatic, so regular screening enables early detection before complications develop (CDC 2024).
How do I interpret the results?
Negative/Nonreactive
- What it means: No evidence of current syphilis infection
- Typical action: Continue routine screening as appropriate
Positive/Reactive (Low titer 1:1–1:8)
- What it means: May indicate treated infection or early disease
- Typical action: Requires confirmatory treponemal testing
Positive/Reactive (High titer 1:16+)
- What it means: Suggests active infection requiring treatment
- Typical action: Immediate confirmatory testing and clinical evaluation
Prozone Effect
- What it means: False negative due to very high antibody levels
- Typical action: Repeat testing with diluted sample
All positive RPR results require confirmatory testing with treponemal-specific tests like FTA-ABS to distinguish true syphilis infection from false positives.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
No special preparation is needed for RPR testing. You don't need to fast, and you can continue taking medications normally. However, avoid biotin supplements 72 hours before testing if your lab uses certain automated assays, as biotin can interfere with results (Mayo Clinic Labs 2024).
Inform your healthcare provider about autoimmune conditions, recent vaccinations, or pregnancy, as these factors may affect test interpretation. The blood draw requires only a standard arm vein sample with no special handling requirements.
How often should I get tested?
- Sexually active with single partner: Annually or when starting new relationships
- Multiple sexual partners: Every 3–6 months
- High-risk behaviors: Every 3 months
- Pregnancy: First prenatal visit and third trimester
- Treatment monitoring: 3, 6, 12, and 24 months post-treatment
Why early detection matters
Untreated syphilis progresses through stages and can cause severe complications including cardiovascular damage, neurological problems, blindness, and death (Mayo Clinic 2024). Early detection and treatment prevent these complications and reduce transmission risk to sexual partners.
The estimated lifetime medical cost of syphilis is $1,190 per infection, with additional productivity costs of $411 per case (CDC Economic Analysis 2021). Early detection through screening like RPR testing prevents these substantial economic and health burdens.
Related tests you may consider
FTA-ABS (Fluorescent Treponemal Antibody Absorption) - Essential confirmatory test for positive RPR results that distinguishes true syphilis infection from false positives and remains positive for life after infection (CDC 2024).
HIV Testing - Strongly recommended alongside syphilis screening due to similar transmission routes and increased HIV risk in syphilis patients. Dual HIV/syphilis rapid tests are now available for simultaneous screening (WHO 2024).
Hepatitis B Surface Antigen (HBsAg) - Recommended for comprehensive STI screening, especially in high-prevalence areas, as hepatitis B shares transmission routes with syphilis and can cause serious long-term complications if untreated (LabCorp 2024).
