VDRL Test in Singapore: A Key Tool for Syphilis Detection and Prevention

What is the VDRL test?

The venereal disease research laboratory (VDRL) test is a widely used blood test designed to screen for syphilis, a sexually transmitted infection (STI) caused by the bacterium named Treponema pallidum. This is a test that detects antibodies that the immune system produces in response to syphilis rather than detecting the bacteria itself. While the VDRL test is a good screening method, further confirmatory tests are required for a definite diagnosis.

In recent years, the rate of syphilis has been increasing, particularly among certain high-risk groups. If left untreated, syphilis can lead to serious complications, such as neurological conditions, cardiovascular disease, and pregnancy complications, including congenital syphilis (when a mother transmits the infection to her baby).

What can the VDRL test detect?

VDRL testing is primarily employed to screen for syphilis, but false-positive results will also be seen in other illnesses. These include:

• Autoimmune diseases:

  • Conditions such as systemic lupus erythematosus (SLE) and rheumatoid arthritis will cause a false-positive result.

• Other infections: 

  • Certain infections, including HIV/AIDS, malaria, tuberculosis, Lyme disease, and leprosy, may cause a misleading positive result.

• Medical conditions: 

  • Pregnancy, recent vaccinations, and liver diseases (such as hepatitis) may also result in temporary false-positive readings.

If you suspect you may have syphilis infections or require STI screening, request an appointment with Thomson Medical today to determine if a VDRL test is the right step for your diagnosis and care.

Why do doctors perform a VDRL test?

Healthcare professionals order the VDRL test for an array of important reasons:

• Syphilis screening: 

  • The test is broadly utilised in the detection of syphilis among individuals at risk, including those who engage in unprotected sexual intercourse or have multiple sexual partners.

• Diagnosis of syphilis: 

  • If a patient presents with genital ulcers, skin rashes, lymphadenopathy, or influenza-like syndrome, the VDRL test is employed to diagnose the syphilis disease.

• Monitoring treatment response: 

  • In patients undergoing treatment for syphilis, the VDRL test is used to monitor treatment responses, reduce the spread of the disease, and ensure that the infection is resolved.

How to prepare for the VDRL test

Usually, no special preparation is required before undergoing a VDRL test, as it is just a simple blood test. However, patients should consider:

• Informing your doctor about any existing medical conditions, recent vaccinations, or autoimmune diseases, as these can affect test results.

• Avoiding unprotected sexual activity before testing to reduce the risk of transmitting infections if diagnosed with syphilis.

• Drinking water and eating normally before the test unless instructed otherwise by your doctor.

How is the VDRL test administered?

The VDRL test can be performed using two main methods depending on the suspected severity of the infection: 

Blood test (Most common method)

• A healthcare provider cleans the skin with an antiseptic to prevent infection.

• A needle is inserted into a vein, typically in the arm.

• A small sample of blood is drawn into a vial for laboratory analysis.

• The needle is removed, and pressure is applied with a cotton swab to stop any bleeding.

• A bandage is placed over the puncture site to prevent further bleeding or infection.

Cerebrospinal fluid (CSF) test  (For neurosyphilis)

• If doctors suspect that syphilis has spread to the brain or nervous system, they may perform a lumbar puncture (spinal tap) to collect cerebrospinal fluid (CSF). The procedure includes:

  • The patient lies on their side or sits upright while the lower back is numbed with a local anaesthetic.

  • A thin needle is inserted into the spinal canal to extract a small amount of spinal fluid.

  • The fluid is then tested in a laboratory to check for syphilis antibodies.

Understanding the results of your VDRL test

1. Normal results:

   • A non-reactive (negative) result indicates that no antibodies (no treponemal infections) associated with syphilis were detected. However, in the early stages of infection, antibodies may not be present in detectable amounts. If you are at high risk or have symptoms, your doctor may recommend retesting after a few weeks.

2. Abnormal results:

   • A reactive (positive) result suggests the presence of antibodies and thus a possible syphilis infection. But because the VDRL test is a non-treponemal test, a definitive diagnosis requires further confirmatory tests.

   • A false-positive result can occur due to other medical conditions, so additional testing is necessary to confirm the presence of syphilis and rule out other potential causes.

Risks of taking the VDRL test

The VDRL test is a safe and simple blood test with very few risks and should not have any long-term complications. However, like any blood test, there are some minor side effects, such as:

Risks of the blood test

• Mild pain or discomfort: 

  • A slight pinch when the needle is inserted.

• Bruising or soreness: 

  • A small bruise may form at the needle site.

• Dizziness or light-headedness: 

  • Rare, but some people might faint after a blood draw.

• Minor bleeding: 

  • Usually stops quickly with pressure.

• Infection (very rare): 

  • If not properly cleaned, healthcare providers follow strict hygiene protocols.

Risks of the CSF test 

• Headache:

  • Common after a lumbar puncture.

• Back pain: 

  • Temporary soreness at the needle site.

• Nausea or dizziness: 

  • Some people may feel unwell for a short time.

• Rare complications: 

  • Infection, bleeding, or nerve irritation (extremely rare).

If you experience prolonged discomfort or unusual symptoms after the test, seek medical attention. Request an appointment with Thomson Medical for further evaluation and care.

Where can I get the VDRL test in Singapore?

There are several options for getting a VDRL test in Singapore, including:

• Public hospitals and polyclinics: 

  • Provide subsidised STI testing for Singapore citizens and PRs. You may need a referral from a general practitioner (GP) or visit a polyclinic offering STI screening.

• Private clinics and sexual health clinics: 

  • Many private clinics offer fast and confidential syphilis testing, with results available within a few days.

• Specialist clinics for sexual health: 

  • Some clinics specialise in STI screening and treatment, offering discreet and comprehensive testing services.

• Non-governmental organisations (NGOs) and community health centres: 

  • Certain organisations provide free or subsidised STI testing services for high-risk groups, including individuals with financial constraints.

Costs of the VDRL test for syphilis in Singapore

The cost of a VDRL test in Singapore varies depending on the healthcare provider and whether additional confirmatory tests are required. Here is a general cost breakdown:

• Public healthcare institutions (polyclinics & government hospitals): 

  • Approximately S$10 – S$50 (subsidised rates for Singaporeans and PRs).

• Private clinics and hospitals: 

  • Around S$50 – S$150, depending on the clinic and additional testing requirements.

• Non-governmental organisations (NGOs) and community clinics: 

  • Some organisations provide low-cost or free STI testing for high-risk individuals.

If you're facing any symptoms of syphilis, a VDRL test is necessary for early detection and treatment. Request an appointment with Thomson Medical to protect your health and prevent complications.

FAQs

How accurate is the VDRL test?

The VDRL test has a relatively high sensitivity (between 50-80%) in primary syphilis and nearly 100% in secondary syphilis, but it becomes less reliable in late-stage syphilis.

Can syphilis be cured?

Yes, syphilis can be cured with antibiotic treatment, primarily penicillin. A single dose of benzathine penicillin G is effective for early syphilis, while late or latent syphilis may require multiple doses.

For those allergic to penicillin, alternatives like doxycycline or azithromycin may be used, but penicillin is still the preferred treatment. Early detection and treatment are crucial to prevent complications. However, damage from late-stage syphilis may be irreversible, even after the infection is cleared.

Is the VDRL test enough for syphilis?

No, the VDRL test alone is not enough to diagnose syphilis. It is a screening test that detects antibodies but can produce false positives due to other conditions like autoimmune diseases or infections.

A confirmatory treponemal test (for example, FTA-ABS, TPHA, or TPPA) is required to verify the diagnosis. If both tests are positive, syphilis is confirmed, and we will need treatment.

What is the difference between RPR and VDRL?

What is the difference between RPR and VDRL?

RPR and VDRL are both non-treponemal syphilis tests, but RPR is faster and does not need a microscope, while VDRL requires a microscope and can test CSF for neurosyphilis. RPR is more commonly used for screening, but both need a treponemal test (for example, TPHA, FTA-ABS) for confirmation.

How can syphilis be transmitted?

Syphilis is transmitted through direct contact with syphilitic sores during unprotected sexual activity (vaginal, anal, or oral sex). It can also spread from a pregnant mother to her baby (congenital syphilis) during pregnancy or childbirth.

Less commonly, syphilis may be transmitted through blood transfusions (rare due to screening) or sharing needles. It does not spread through casual contact, such as hugging, sharing utensils, or using the same toilet.

Why is syphilis testing recommended during pregnancy?

Pregnant women should be tested for syphilis because the infection can be transmitted to the baby during pregnancy (congenital syphilis), causing miscarriage, stillbirth, or severe birth defects. Early detection through VDRL or RPR tests allows for timely treatment with penicillin, which can cure the infection and prevent transmission to the baby.

What additional tests are needed after a positive VDRL test?

If the VDRL test is positive, a treponemal test such as the FTA-ABS test (Fluorescent treponemal antibody absorption), TPHA (Treponema pallidum haemagglutination assay), or TPPA (Treponema pallidum particle agglutination) is required to confirm syphilis. In cases of suspected neurosyphilis, a VDRL test on cerebrospinal fluid (CSF) may also be done.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations based on your medical conditions, request an appointment with Thomson Medical.