VDRL And TPHA Tests
Afternoon dock. I want to ask about VDRL and TPHA tests. I have symptoms of a red rash that is not itchy, with a diameter of approximately 0.5 cm, the rash is on the wrist, neck and back of the knee folds. I have had serological tests for hepatitis, HIV, herpes, syphilis and all the results are negative, but what I suspect is syphilis, because the symptoms are similar to syphilis, I feel the results of the VDRL and TPHA tests are wrong. what I want to ask: 1. Do both tests include rapid tests? 2. Can the test produce false negatives after 7 months to 1 year after performing risky actions? 3. How accurate are the results of the test after 7 months of taking risky actions?
Hello Arifin, thank you for asking at HealthReplies.com.
Syphilis is a sexually transmitted infection that is caused by the bacterium Treponema pallidum. The symptoms that are caused vary depending on the stage of the disease. If what happens to you is a rash on your body, it is likely that syphilis is at a secondary stage.
To detect syphilis screening can be done at least once a year or every 3-6 months if it is very risky. Syphilis screening is broadly divided into two types:
Nontreponema test, this examination is sensitive to see the presence or absence of syphilis infection, but because it can be positive in several other conditions such as in passing or malaria, the examination is not specific to syphilis infection. This examination is very easy and inexpensive to do. One of these tests is the VDRL (Venereal Disease Research Laboratory)
Treponema test, conducted to confirm the results of nontreponema examination. This type of examination will specifically detect antibodies that are related to the bacteria that cause syphilis. With a combination of the two types of examination, it can be seen whether the infection is active or the old infection has healed. One such examination is the TPHA (Treponema Pallidum Haemagglutination Assay).
Examination can be a false negative if done during the initial phase of infection, which is around the first 3 months. And the accuracy of the examination certainly depends on the time of examination and also how severe the disease has occurred, but in general the level of accuracy of syphilis screening reaches 75-85 percent. However, this must also be confirmed by clinical genala and examinations carried out. You can see your doctor to further discuss your complaint. For now, avoiding sexual relations by changing partners is highly recommended.
That's all, hope it helps.