I am a new user and this is my first question. I wasn't able  to locate where you  submit the first question. I hope you get this. 

If you indeed were tested at 6 month intervals, i.e. if your syphilis diagnosed in September had been present less than a year, then by definition you had "early" syphilis. That's a good prognostic category and predicts excellent redsponse to penicillin. Your high RPR (or VDRL) titer of 1:256 tends to confirm early infection. You probably were over treated:  a single dose of benzathine (long acting) penicillin would have been sufficient. (That's not a criticism of your doctor. Over treatment is always better than taking chances of under treatment.) The decline in your titer to 1:8 is right on schedule or even ahead of it. The standard evidence of adequate response to treatment is a 3-dilution decline in titer by 6 months; in other words, even a titer of 1:32 at this time would be on schedule. You should plan on continued testing at roughly 3 month intervals, or whatever your doctor recommended. Most likely your titer will continue to decline, perhaps to entirely negative by next September -- although it would not be abnormal or alarming for it to remain weakly positive for still longer. You should then plan on retesting about once a year for the next 4-5 years. Late treatment failure is unlikely, but better safe than sorry; and follow-up testing also is recommended to detect potential reinfection.

As for contagiousness, no worries. You were non-contagious within a day or two of the first penicillin injection. Even in the unlikely event of late treatment failure -- i.e. if your RPR/VDRL titer were to rise again after dropping to its low point, whatever that turns out to be -- you will remain non-contagious for partners. Distant reactivations of syphilis generally are not transmissible. However, you say nothing about your regular partner. Assuming you and he were having sexual contact with one another during the past year, he was exposed and possibly infected. If not yet done, he of course needs to be informed and tested, and he should have already been treated with benzathine when you were, i.e. without waiting for his own test result. (If that was not done, it throws my analysis above into doubt. In that event, you could have been reinfected from him, and you also will need another round of treatment.)

Presumably you are HIV negative or you would have mentioned it. But if positive, speak to your doctor about possibly more frequent follow-up syphilis blood tests, perhaps every 3-6 months instead of annually. Having HIV somewhat raises the risk of distant reactivation.

The bottom line is that almost certainly you are cured and for sure you are not infectious for partners. But stick with the program for follow-up testing just to be on the maximally safe side. But please do confirm that your regular partner has been treated. I hope this information has been helpful; let me know if anything isn't clear.

Best wishes and stay safe--  HHH, MD

Thank you so much for your response. Yes your response was very clear, and makes me feel much better. Since receiving treatment  my partner and I haven't really been sexually intimate. We have only kissed, no anal sex at all or oral sex since treatment...that I can remember. I know for sure since mid December.  But yes I do agree it would be a good and safe thing for him to get tested to be sure.  I am overall a very healthy male, HIV negative and was negative for the other basic STD's on my last visit. 

What prompted my question and to reach out for your help and expertise was an recent experience. 

I was out of town on a vacation  and played around with a guy that I know for the weekend. Friends but live far apart and hadn't seen each other in a few years.  We kissed, had oral sex (both to each other), anal sex (with a condom, and once  with out for just a  minute, where I penetrated him but again for a minute..nothing continuous and no exchange of fluids). He was a little freaked out the next morning, and of course I was also.  I just needed some reassurance from you to make me feel a little better. I would hate and feel devastated if I gave him something. Thanks again for your help and time.  Again please reassure me or let me know if I need to follow up with anything or communicate anything to him. I do plan of getting tested in a few months to follow up with the titer etc. 

As for the more recent encounter, for the reasons described above, there is no possibility your infected your partner with syphilis.

However, I hope you don't mind an unsolicited observation. I think you have a lot of denial about your sexual risks. Obviously you have a sense of concern for your health and responsibility for protecting it, and for preventing harm to your partners. Congratuations -- it's a great start. But on the other hand, sometime in the past year you had at least one exposure when you acquired syphilis, which implies high risk both in who you select as partners outside your main relationship and in sexual practices -- i.e. there has been high risk unprotected sex. And now you describe "brief" unprotected anal penetration with someone who, you probably can assume, may have risky practices himself. (He agreed to casual sex with you, so why not others?) And you're kidding yourself in rather outstanding fashion if you believe there is any kind of anal sex that doesn't involve "exchange of fluids". I suspect you are habitually riskier than you think, or than you have admitted to yourself, and that there's a good chance HIV is in your future if things don't change. (Simply having had syphilis marks you, epidemiologically and statistically, as very high risk for HIV.) This isn't intended as criticism -- just the words of someone who has dealth with hundreds of patients with stories like yours.

No I totally agree with you and I appreciate your response and concern. Having had syphilis this past year and being in other situations has really been an eye opening experience for me.  I am aware of my behavior and actions and actually feel blessed that I haven't gotten anything that is not curable, like HIV. It is a scary world and people lie and are hard to trust. I have had to really be careful, pray, and look at my life  the past few months for sure. I again appreciate your help, advice and concern. 

My friend from the trip is actually married and doesn't do much "high risk" behavior to my knowledge. That is way I was so worried and concerned about things. Again a very eye opening experience for me. I do care very much about my health and the health and well being for others. Thank you again. 

Thanks for the thanks. I'm glad to have helped. Best wishes.