[Question #5525] Question 5501 follow-up

20 months ago

Hello doctors, this is a follow-up to question 5501. To summarize. May 20, encounter with a CSW, condom protected fellatio, vaginal intercourse mostly protected ( condom slipped off for 15-30 seconds with possible external genitals contact ) . May 29 , CSW tested for HIV ( negative ) VDRL and TPHA ( positive ) . Denies previous syphilis,  I doubt she’ s telling the truth  though . Anyway considering her  as having active syphilis I got on the 10th of June ( day 21 post event ) as suggested, prophylactic  benzathine penicillin 2.2 million i.m. ( 0.2 million to dense to inject remained in the syringe, my weigh is 76 kg. ) . Absolutely no local signs or changes at the penis, scrotum and pubic area  level . Today ( day 23 post event )  I’ ve got tested  in a private lab: VDRL ( monophase syphilis card  ) negative, TPHA ( microplate hemoagglutination ) negative  (in a score between   neg and 4+ ) .

Questions.

1.       At this point considering the absence of local signs and the negative test is it possible to rule out syphilis , or should I repeat the test  ( maybe a different one ) in the next weeks? As I stated before I’ ve read various answers indicating  6 weeks negativity  as the definite time to exclude syphilis .

2.       Following the risky event I had only a single vaginal intercourse with my wife on the 4th of June (  15 days post event - at that time I was aware of the CSW  HIV negativity only  and could not presume the syphilis test positivity ) . Considering the complete absence  any local lesions ( “No lesion, no reactive tests, no risk encounter  “ , Dr. Hook answer to question 5436 ) , and subsequent negativity of test ( even if early, maybe ) , can I be positive that my wife was non exposed to the risk of syphilis transmission and , if it that’ s the case no test will be needed and more so  no treatment for her  ?

3.       The dose of benzathine penicillin 2.2 instead of 2.4 could be a problem? Also I recall that I had 2 pills of doxyciclin on the 9th of June when It seemed difficult to get benzathine penicillin.

4.       Is that true that from 7 days following benzathine penicillin injection one can resume a regular sexual activity without any risk for partner ?

I mostly appreciate your help.

 

H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
20 months ago
Welcome back. I reviewed your discussion with Dr. Hook. The new information now (unless I missed it there) is that have had a negative serological test for syphilis. That makes it clear you did not have syphilis before the encounter. And done 3 weeks after the exposure to a possibly infected partner, it is slightly reassuring that you did not acquire syphilis at that time. But only slightly. More important is that you developed no lesion suggestive of a chancre. That fact, plus the likelihood that your partner did not have active (transmissible) syphilis, plus the negative blood test add up to a very low probability you were infected. The benzathine penicillin further assure you do not have active syphilis. To your specific questions:

1) True that it takes up to 6 weeks for blood test positivity. However, there is no possibility now. With BPG before either chancre or detectable antibody, even if you were infected, the syphilis has been aborted. Nobody in this situation ever develops positive blood tests later. So another test is really not necessary. You could do it if you will find another negative test result reassuring, which I would understand. But it is optional, strictly for reassurance, not because of any realistic chance it would be positive.

2) Even if exposed to syphilis, sex before development of chancre is risk free. As just discussed, it is unlikely you were infected. But even if you were, your wife was not yet at risk 2 weeks after exposure. She does not need treatment.

3) There are no data on that exact dose, but even 1.2 million units usually would be effective at aborting incubating syphilis, even though not officially recommended. There certainly can be no difference in effectiveness between 2.2 and 2.4 MU.

4) Even with active syphilis with chancre, the infection becomes non-transmissible within 24 hours. 7 days is recommended to provide a conservative safety interval but probably is unnecessary. In any case, in your situation it doesn't matter. You never were infectious for your wife and certainly are not now. You need not wait even another day.

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

HHH, MD
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20 months ago
Thank you Dr. Handsfield and Dr. Hook, one last point to clarify : you say my wife doesn't need treatment, I assume she doesn't need to be tested either. Am I correct?
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
20 months ago
Correct.---
20 months ago
Thank you again Dr. Handsfield , everything is completely clear to me now. Let me 

stress that your 
20 months ago
Let me stress that your job is of outmost importance for patients and heathcare professional also. All the best,
 A.G.
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
20 months ago
Thanks for the thanks. Dr. Hook and I are glad to have helped you through this difficult period. Best wishes.---