The venereal disease research laboratory VDRL test is designed to assess whether you have syphilis , a sexually transmitted infection STI. Syphilis is caused by the bacterium Treponema pallidum. The bacterium infects by penetrating into the lining of the mouth or genital area. Instead, it checks for the antibodies your body makes in response to antigens produced by cells damaged by the bacteria.
Antibodies are a type of protein produced by your immune system to fight off invaders like bacteria or toxins. Testing for these antibodies can let your doctors know whether you have syphilis. Because it checks for antibodies produced as a result of a syphilis infection, the VDRL test can be used regardless of whether you currently have any symptoms. Learn more about another type of syphilis test, the RPR test. Early symptoms that may prompt your doctor to order this test include:.
Usually, all you need to do for the VDRL test is allow a healthcare professional to draw your blood. Blood is generally drawn from a vein at the crease of the elbow or the back of the hand.
This blood sample will then be sent to a laboratory and tested for the antibodies produced as a result of syphilis. If your doctor suspects that the syphilis infection has spread to your brain, your doctor may choose to test your spinal fluid in addition to your blood. If your test comes back positive for syphilis antibodies, you probably but not definitely have syphilis. If this occurs, your doctor will order a more specific test to confirm the results.
A treponemal test is often used to confirm the positive test. The VDRL blood test is not always accurate. Infections, such as HIV or pneumonia , as well as other autoimmune disorders, can trigger a false-positive result. If the result is positive, a doctor will perform another test, such as the fluorescent treponemal absorption assay.
This test will be able to confirm whether the infection is syphilis. If a person receives a positive result, a doctor will typically perform a treponemal test, which detects the antibodies to the T Pall i dum proteins.
If this is positive, it indicates that syphilis has infected the central nervous system. Sometimes, however, doctors test for syphilis in reverse.
They will begin by testing a person with a syphilis-specific treponemal test. If this proves positive, they will follow it up with a nontreponemal test, such as a VDRL. The VDRL test offers a safe and convenient way to screen for syphilis infections.
The test itself does not carry any significant risks. However, there may be some slight complications associated with the process of drawing blood and lumbar punctures.
A chancre appears during the primary stage of syphilis. This is when skin rashes and lesions appear. They may occur in the vagina, the anus, or the mouth.
A person may also develop a fever, muscle aches, swollen lymph glands, sore throat, and hair loss. This stage can be fatal and typically occurs between 10—30 years after the initial infection.
This can occur at any stage of the infection. Ocular syphilis affects the eyes, and neurosyphilis affects the brain and nervous system. Symptoms include headaches, paralysis, dementia, difficulty coordinating muscles, and a change in behavior. Doctors and other healthcare providers use the VDRL test to screen for syphilis. Syphilis is an STI caused by the T.
In order to perform the test, a healthcare provider must collect blood or a sample of spinal fluid. These procedures can cause minor side effects, such as headaches, bruising, and soreness near the injection site.
People who have negative results mostly likely do not have syphilis. However, a doctor may recommend repeating the test at a later date if someone had a recent exposure or has a high risk for syphilis. The zone of equivalence defines this optimal ratio. In the eve of antibody or antigen, excess prozone and postzone, respectively false-negative test result will arrive. It needs to be confirmed by a treponemal test. If history of syphilis is present, then the criteria should be a fourfold rise in titer.
In all patients with late latent syphilis, lumbar puncture is recommended to exclude neurosyphilis. As the number of organisms are too low in late stages, polymerase chain reaction PCR technique may be a very useful test in establishing a diagnosis.
Optimally pregnant women should be screened for syphilis at their first prenatal visit, during third trimester, and at the time of delivery with a nontreponemal test VDRL or RPR. For mothers with:. The infant should receive an evaluation for clinical signs and symptoms of syphilis. This evaluation must include a nontreponemal serological test performed on infant serum, not cord blood. Titers may increase slightly in serofast women who were previously treated for syphilis become pregnant.
It is generally less than fourfold increase. Serological response to treatment is similar to that of non-pregnant women. The diagnosis of congenital syphilis is complicated by the trans-placental transfer of maternal nontreponemal and treponemal IgG antibodies to the fetus.
This transfer of antibodies makes the interpretation of reactive serologic tests for syphilis in infants difficult. Treatment decisions frequently must be made on the basis of 1 identification of syphilis in the mother; 2 adequacy of maternal treatment; 3 presence of clinical, laboratory, or radiographic evidence of syphilis in the infant; and 4 comparison of maternal at delivery and infant nontreponemal serologic titers using the same test and preferably the same laboratory.
Venous blood from both the mother and the child should be tested. Asymptomatic congenital syphilis requires a comprehensive approach. All infants born to mothers who have reactive nontreponemal and treponemal test results should be evaluated with a quantitative nontreponemal serologic test RPR or VDRL performed on infant serum because umbilical cord blood can become contaminated with maternal blood and could yield a false-positive result and should be examined thoroughly for evidence of congenital syphilis e.
Conducting a treponemal test i. A BFP test result is rare in spinal fluid. A nonreactive VDRL test may indicate that the patient does not have neurosyphilis. However, a negative result can occur in some patients with neurosyphilis. CSF treponemal test have high sensitivity and are helpful only when test is negative. A nonreactive test probably excludes neurosyphilis, but a positive test is not always diagnostic for neurosyphilis.
However, in a patient co-infected with HIV and syphilis, it is difficult to diagnose neurosyphilis on the basis of CSF changes. For patients with neurosyphilis, repeat serologic testing and CSF examinations at 6-month intervals are recommended until the findings have stabilized. If the CSF white blood cell count is not normal or the CSF-VDRL remains reactive at 2 years, and if no other cause is identified, then the patient should be re-evaluated and re-treated for neurosyphilis.
In conclusion, it seems that the Treponema pallidum particle agglutination technique TP. PA can be used in CSF to diagnose neurosyphilis, although as for other serological tests, interpretation of results should be done in conjunction with other neurosyphilis parameters. The interaction between syphilis and HIV infection is complex and remains incompletely understood, despite there being more than two decades of clinical experience with co-infected patients.
Serologic tests for syphilis are the cornerstone of diagnosing untreated syphilis infection, independent of HIV status. Nontreponemal assays, such as the RPR card or VDRL test, use cardiolipin-, lecithin-, and cholesterol-containing antigen to measure antilipoidal antibodies and are often used initially to diagnose syphilis.
Because the sensitivity of nontreponemal tests is lower that that of treponemal tests in the primary stage, a negative nontreponemal test in an HIV-infected individual with a genital lesion cannot exclude primary syphilis. It may be useful to consider both a nontreponemal and a nonreflexed treponemal test as a diagnostic strategy in newly infected persons with suspicious lesions.
Unusual serologic responses have been reported in HIV-infected persons with syphilis. Most reports involved higher than expected serologic titers, but false-negative serologic results and delayed appearance of sero-reactivity have also been reported, albeit rarely. Nevertheless, serologic tests appear to be accurate and reliable for the diagnosis of syphilis and the evaluation of treatment response in most HIV-infected patients. The clinician should seek confirmatory evidence for the diagnosis from any available source, including the patient's history, clinical findings, direct examination of lesion material for spirochetes, and serologic tests for syphilis.
Reports of nontreponemal antibody test results should be quantitative and describe the lowest dilution i. The interaction of syphilis and HIV infection is complex and remains the subject of ongoing research.
Although case reports have suggested that coexisting HIV infection may alter the natural history of syphilis, only a few such effects have been demonstrated in large observational studies.
Initial serologic responses to early syphilis were shown to be generally equivalent in HIV-negative and HIV-positive patients. Nevertheless, both treponemal and nontreponemal serologic tests for syphilis are accurate in the majority of patients with syphilis and HIV co-infection.
Irrespective of sign and symptoms, all HIV-positive patients should have baseline VDRL screening and follow-up at 3 months to rule out the possibility of false-negative results, as seroconversion generally takes about 4—6 weeks after infection.
Repeat testing is indicated in both instances. HIV is considered to be one of the important causes of false-positive reaction to syphilis serology; but this conception needs to be reinterpreted as most of the studies on syphilis serology in HIV positives have used populations that include those involved in IV drug use, a behavior that is an independent risk factor for false-positive serology.
Further prospective study on the HIV-infected patients with biological false-reactive VDRL results to assess the seroconversion pattern and possible silent abnormality is recommended. There is no ideal test of cure of syphilis available that can be carried out within days or weeks after treatment to determine the status of a patient. Patients should have serological tests for syphilis done on the day treatment is initiated. When serological test is negative, patient is assured to be cured.
Generally, seropositivity is achieved in majority of the patients with primary syphilis in about 12 months after the treatment and in those with secondary syphilis in about 24 months. Seroconversion is more rapid after therapy if duration of infection is short and initial titer is low. As seroconversion is a slow process requiring months to years, the rate of decline is a better indicator of therapeutic response.
A 4-fold decrease in titer is considered as good response, and this should occur within months after therapy in patients with primary and secondary syphilis and within 12 months in patients with early latent syphilis. There is no satisfactory monitoring test available for nontreponemal test-negative late disease. Nonreactive serologic tests and normal clinical evaluation cannot exclude incubating syphilis.
Some experts recommend that HIV-infected patients be followed more closely at 3-month interval.
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