[Question #11770] Syphilis Results and Staging

12 months ago

I am a 29-year-old homosexual male. Last week, I was diagnosed with syphilis via a reactive RPR test (1:128 titer). I was treated with one penicillin shot (2.4 million units). About three weeks ago, I had an unusual sore on my chin that excreted clear liquid and had a yellow crust. I also recall a small dot/pimple on my tongue about a month ago and a swollen lymph node under my jaw.

My doctor suspects a recent infection. My last STD test, 12 months ago, did not include syphilis. Over the past year, I have had 1-2 sexual partners per month, mostly unprotected oral sex. On one or two occasions, a partner briefly inserted their penis into my anus before I asked them to stop.

My questions:

Is a titer level of 1:128 consistent with a very recent infection (within the past 3 weeks to 1 month)?
Could the sore on my chin or the bump on my tongue have been chancres?
If I had oral syphilis, how could I have transmitted it to others? Would my partners need open sores/broken skin to become infected? Could it be transmitted through kissing?

Thank you.

H. Hunter Handsfield, MD

12 months ago

Welcome. I'm happy to address these issues.

RPR titers as high at 1:128 often indicate syphilis of under a year in duration (the cut-off definition for "early" syphilis), but 3-4 weeks definitely is too soon. The RPR doesn't even start to become detectable at low titer sooner than that time, and most cases at your level are at least 2-3 months in duration. And it certainly is possible you have been infected a year or more. Too bad syphilis wasn't included last time you were tested for STDs a year ago. What sort of potential risks were there beyond a year ago?

The lesion of primary syphilis (chancre) can be highly variable in appearance, but usually doesn't drain liquid (clear or otherwise). The tongue lesion plus regional lymph node inflammation could have been primary syphilis, but that's still a problem in interpreting your high RPR titer.

Do you have HIV? People with HIV often have higher than usual RPR titers and sometimes accelerated progression of RPR to high levels.

Syphilis does not need obvious open sores or symptoms to be transmissible. You should assume all your sex partners in the past few months and perhaps even longer were at risk or could have been the source of your infection. Most likely your infection has been reported to your local or state department of public health. You should expect to be contacted, or to contact them yourself. Don't be intimidated by this process: it's less coercive than many people fear and usually very helpful in judging the duration of infection and helping protect partners.

Those comments cover your first two questions. For question 3, you probably have (or recently had) secondary syphilis, regardless of absent symptoms; and secondary syphilis is associate with multiple sites of potential transmission, regardless of where the inoculation occurred. Your brief anal sex exposures could have been the source of your infection, and also likely put your partners at risk. Absence of anal symptoms doesn't exonerate that as a source of transmission or acquisition.

Finally, if early syphilis cannot be confirmed, you and your doctor should consider the possibility it is a year or more in duration. If so, or if there is any doubt, you need two more doses of benzathine penicillin; standard treatment is 2.4 million units weekly for 3 doses. Judging this also is a potential benefit of contact with public health.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

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12 months ago

Thank you for your response. I do not have HIV thankfully. I had a sexual encounter 6 weeks ago with someone who seemed to have a lot of random sex. I am wondering if this timeframe could coincide with a 1:128 level? Would you consider this level to be highly unusual for an infection that has existed for over one year?

In terms of trying to stage this - if the one shot of penicillin successfully brings down my levels , does that not provide sufficient evidence that it was in fact early stage syphilis?

H. Hunter Handsfield, MD

12 months ago

Six weeks would be awfully early for RPR 1:128, but might be possible. If that partner is identifiable and can be located (here too the health department probably would take responsibility), and if found to have active transmissible syphilis, that would support this possibility. But still, I think it's much more likely your infection is at least 3 months in duration. A titer of 1:128 is not at all unusual for syphilis more than a year in duration (but probably not longer than 2-3 years).

Your RPR titer will decline even after one dose of penicillin, but if there is any significant possibility you have had it a year or more, you definitely should have the additional two doses. Please discuss all this with your doctor; you could consider printing out this thread as a framework for that discussion.

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12 months ago

I am a bit unclear regarding the need for additional shots of penicillin. My doctor seemed to suggest if during my follow-up tests if a fourfold decrease in my titer level is observed than it was successful and indicative of an early syphilis case. She also said that after my shot last week I am no longer contagious. Am I misunderstanding?

Regarding past sexual partners, I have advised everyone to get testing. Since I typically only give oral and on rare occasion bottom, then I assume anyone infected would have had a chancre on their penis. In the majority of cases of syphilis, does a penis chancre appear if the person in infected? How would I describe what the chancre typically looks like / what to look out for? I understand they are vary in appearance.

12 months ago

Also, lastly, what percentage of secondary syphilis cases are symptomatic (i.e., lesions, rash, etc.)?

H. Hunter Handsfield, MD

12 months ago

Your doctor is correct about the 4-fold titer decline standard. Still, the universal advice -- CDC, WHO, European Union, and most if not all countries' recommendations -- is that syphilis a year or more in duration should be treated with three weekly doses of 2.4 million units of benzathine penicillin G (BPG). Here are the current CDC guidelines; the syphilis section starts on page 39 and treatment of latent syphilis p. 44 (see the box at lower left of the page). https://www.cdc.gov/std/treatment-guidelines/STI-Guidelines-2021.pdf

The science behind this, i.e. the need for more than one dose, is weak -- and at a personal level, I doubt it's always necessary. But that's the scientific consensus. An initial 4-fold titer decline does not rule out the possibility of later relapse. (FYI Dr. Hook and I have been involved in CDC's guidelines every cycle, roughly every 4-5 years, since 1989. We have helped write the syphilis treatment recommendations.)

Your doctor also is right about transmission after treatment: syphilis ceases to be transmissible within a few hours of the first dose.

I would advise not being highly specific about the kinds of contact that could have resulted in your syphilis and the risk to your partners since you were infected, whenever that was. And it should not be your responsibility to tell them what symptoms to look for. Regardless of symptoms, they should be professionally examined and tested. (Here once more is the desirability of public health involvement. They're the experts in such advice and partner management in general.)

All in all, it sounds like your doctor is very knowledgeable about syphilis. My guess is that she has advised only one dose in the belief you've had it less than a year. It seems likely she would agree with the need for 3 doses if there is a chance you've had it more than a year. In my clinic, there is little doubt that would be our advice, and it certainly is my professional advice now.

All things considered, undoubtedly you will do well. You can expect to have at least a 4-fold decline in RPR titer over the next few months. But I do hope you'll get two more doses of BPG.

That completes the two follow-up exchanges included with each question and so ends this thread. I hope the discussion has been helpful.

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