How long to wait for confirmation of effective syphilis treatment

[levi153]

Hello

During a routine STD testing (gonorrhea through throat, rectum, and uretha, chlymydia through urine, HIV and syphilis through blood) I tested postive for syphilis (negative for all other tests).  I show no symptoms, and haven't shown symptoms in the past year, therefore I have been diagnosed with a primary infection which was likely recent as in mid-December 2010 (3 months prior) I was negative for all STD tests and haven't shown any symptoms.

I have been treated with the standard benzathine penicillin G 2.4 million U IM in single session.

As syphilis is transfered through open sores and not necessarily through bodily fuilds such as HIV is, my assumption is that in the absense of sores and a full course of treatment (injection) I should be safe to resume having sex again in perhaps as soon as a week.   (Of course, ensuring that my partner has also been similarly treated, and had a "case history" similar to mine.)

A week following treatment, is it safe for me to engage in sex again?  If not, how long should I wait?  My understanding is sometimes blood test results may still be positive for syphilis for a period after treatment due to the presence of antibodies still in the body.  When are blood tests reliable again after an infection and subsequent treatment in the primary stage?

Thanks for your advice!

[Edward W Hook, MD]

Welcome to our Forum. I have several comments which I hope will be helpful to you.  First, I think that your syphilis would be classified as latent syphilis of unknown duration, not primary syphilis.  The diagnosis of primary syphilis is based on the presence of a sore or lesion.  On the other hand, persons with latent syphilis do not have lesions, by definition.  Unless you or your partner (presuming your partner's blood test is also positive) has a sore, or one of has had a negative blood test for syphilis in the past year, the duration of your infection is unknown.

Recommended therapy for latent syphilis which can be proven to have been present for less than a year (by having had a negative blood test in the past year or a partner who has a definitive lesion) is 2.4 million units of benzathine penicillin.  If the duration of the latent infection is unknown, then recommended therapy is weekly injections of 2.4 million units of benzathine penicillin for 3 successive weeks.

Following a single injection of benzathine penicillin, persons quickly become non-infectious to others and certainly can resume sex without concerns of transmission of infection a week following receipt of the first injection of penicillin.

Repeat blood tests are the correct way to follow response to syphilis therapy but this can take months to occur and in as many as 20% of persons with recently acquired syphilis, the blood test may not go down but will remain stable.  This is called a "serofast" state.  As long as the blod test is not going up however, you can probably assume your syphilis has been adequately treated.

I hope these comments are helpful. EWH

[Edward W Hook, MD]

The timeline for determining when persons's have responded to therapy or are serofast is determined based on the stage of syphilis diagnosed, as indicated above - 3 months for primary syphilis, 6 for early latent.  EWH

[levi153]

Thanks again Doctor for your quick and helpful advice.  I have contacted all my partners in the past 6 months to notify them they may be at risk and will abstain from any sexual activity for a week to ensure the infection is cured by the injection.  Also, when I become sexually active again, I'll ensure if it is with past partners they have also been treated and have waited the requisite week as well to prevent re-infection.

As a final question, at what point (how many months post-treatment) would you generally make the judgement call that a person is serofast assuming stable blood test results?

[Edward W Hook, MD]

The time for response depends on the stage of infection. Typically if you really did have primary syphilis it woul be expected for you to have blood test response by 3 months.  With early latent infection response can take up to six months.,  As I said, up to 20% of persons will not show a blood test response, being serofast with stable blood test results.  This is NOT an inidcation of treatment failure.  EWH

[levi153]

My apologies for not consolidating these two questions.  However, your initial response indicated it could take "months" for blood test results to come back negative again for syphilis even though the infection is likely cured within a week of the injection or in about 20% of the cases for the blood test to never go back to negative again.

In your experience, what is the general period you would except to go by until you make the judgement that the test simply won't come back negative again?  How long does it "normally" take for a negative result again if I fall within the 80% that would enter back into that territory after treatment?

[levi153]

Thanks Doctor for the quick and helpful response.

As indicated my last negative syphilis test was in mid-December 2010.  What is the window period for blood tests for syphilis?  I want to ensure that I contact my past partners so they too can be tested.

For example, if the window period is one month I'll contact partners from now until November 2010.  I am otherwise a healthy male who has not been ill at all this winter.

Thanks in advance!