The use of one type of test alone can be insufficient, and can produce false positive results.
Nontreponemal tests
You will first be screened for syphilis and only given further testing to confirm if the initial screening results turn out positive.
These screening tests include:
- Venereal disease research laboratory (VDRL) test – This test looks for a high amount of antibody production to confirm infection.
- Red plasma reagin (RPR) test – This looks for antibodies produced against syphilis. They specifically look for antibodies directed against the cells already damaged by the infection.
- Rapid immunochromatographic test – This test uses a nitrocellulose strip, similar to a pregnancy test. The strip contains a mix of antigens and a selenium colloid (a serum) which reacts to antibodies against syphilis. Just like a pregnancy test, the area with the colloid will show up as a line if there is a reaction between the antigen-selenium mix and the antibodies that the test is looking for.
Treponemal tests
More detailed tests to confirm syphilis include:
- Fluorescent treponemal antibody absorption (FTA-ABS) test – This test looks for compounds present in antigens found on the surface of the bacteria. A special light source and filters illuminate those compounds in the antigen. This causes the antigen to glow, making the bacteria far easier to locate.
- Dark-field microscopy – Dark-field microscopy darkens the areas around the observed bacteria to make it easier to observe. It filters out the unnecessary parts of the image and amplifies the observed object. This creates a stark contrast of a nearly black background with bright objects in it.
- Polymerase chain reaction (PCR) test – This test uses the bacteria’s DNA and makes millions of copies using advanced machinery. This will make it easier to observe and identify the bacteria present in the sample.
Key Takeaway
In conclusion, testing and diagnosis for syphilis have become fairly advanced and very reliable. These include nontreponemal and treponemal-specific tests. As long as you can detect the infection on time and have it treated, you can say goodbye to syphilis.