« Go Back

Syphilis Diagnosis


3 Months ago i started having a reddish rash (no warts or sores) on my face, over the cheeks area. I went to the doctor and he suggested getting some exams, i got tested for HIV, Chlamydia and Syphilis and the last one came out positive (1:32)

After the exams i got 3 shots of penicillin with the last one being applied by January 2nd. After that i haven't had any follow up exams until last week that i took the VDRL and it came out (1:32) reactive again.

Does that mean the penicillin didn't work?

PS: i haven't had any sexual activity in the past 4 months



Thank you for your inquiry. From what we gather from the question, you were asking about a 1:32 reactive Venereal Disease Research Laboratory (VDRL) syphilis test 3 months after receiving treatment for syphilis, which was diagnosed with a 1:32 reactive VDRL test.

It is responsible to get tested for HIV and other sexually transmitted infections after engaging in risky activity. Syphilis is a bacterial sexually transmitted infection that can be successfully treated with penicillin. Of the available tests for syphilis there are two different types of antibody tests that could be used at a laboratory. Note that they are often both used together for identification or for confirmation of a syphilis infection (1). One type of test is called a treponemal test (eg. Treponema Pallidum Particle Agglutination (TPPA)) which detects antibodies that the body makes against the actual syphilis bacteria (2). Treponemal tests will typically stay positive for the rest of your lifetime (similar to an HIV antibody test). The other type is called a non-treponemal test (eg. VDRL or Rapid Plasma Reagin (RPR)) and it detects antibodies against specific molecules that are released when cells in your body are damaged by the syphilis bacteria (2). A non-treponemal test, such as a VDRL, is typically used to identify if a syphilis infection is active since it detects the immune response to the infection. A non-treponemal test can stay positive for many months after successful treatment of the infection since these specific antibodies take a while to be cleared out of the body, but will typically become undetectable after 6 months. Please note that syphilis infections that have lasted many years may take up to 2 years to become undetectable or may never become undetectable using a non-treponemal test.

It is very unlikely that the penicillin did not work, as it is an extremely effective drug against syphilis infections. Re-testing after 6 months using a non-treponemal test (VDRL) may help ease your worry.

Recommendation: Refer to a physician for other health related questions.


AIDS Vancouver Helpline/Online, Marie