[Question #5032] Testing and medicine

23 months ago
Good evening Doctors,

I had a sexual encounter on the 15th of December with a women, vaginal sex and no condom. I took a 4th gen ag/ab test 23 days post exposure - negative and also 38 days post exposure- also negative.

I am now reading that 6 weeks is 100% so I am just curious how accurate is my 38 day test vice 42 days?  Is there a major difference in 4 days?

Also I was given 1g azythromycin followed two days later by a suprax 400mg tablet for possible chlamydia and gonnorhea prevention, should I have been given both pills and taken them the same day? Thank you in advance for your time.
Edward W. Hook M.D.
Edward W. Hook M.D.
23 months ago
Welcome to the Forum.  I happened to be on the Forum at the time your question arrived so you are receiving this reply a bit sooner than is the norm.  

In the past we quoted 4 weeks as being the time point at which 4th generation, combination HIV antigen/antibody tests provided conclusive results but we modified our statement about a year ago when the CDC published guidelines that used the 6 week timepoint as their cutoff.  It is our understanding that there are a very small number of persons who have become positive on these tests between weeks 4 and 6 after exposure.  that number of persons however is very small and neither of us has ever seen such a case.  Your 38 day result is at lest 99% conclusive and unless there is something particularly high risk about the encounter you describe (few women have HIV and the risk of HIV from any single unprotected vaginal sex exposure with an untreated HIV infected woman is less than 1 infection per 1000 acts of intercourse) I really would not be at all worried and would not feel the need for further testing related to that event.

Taking the azithromycin and cefixime two days apart for a possible infection would not change their effectiveness meaningfully.

I hope these replies are helpful.  EWH
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23 months ago
Dr. Hook, that was some great timing! The encounter was at a party, I later found out the girl had slept with another man prior to me that evening. So that had me very worried. I had found out she had unprotected sex with him also. When I questioned her she said she had a test completed at planned parenthood 2 weeks after the party, a finger prick test that was negative.

Also so the timing and dosage of medications prescribed for sti is adequate? And what is the time for those medications to fully function and take car of any sti I may have gotten?
Edward W. Hook M.D.
Edward W. Hook M.D.
23 months ago
Your partner certainly sounds as though she was at relatively high risk for infection but you still do not know that she was infected and in fact, it is unlikely that she was from a statistical perspective.  Further, she indicated recent negative testing.  I would not worry that your antibiotics (which were probably not needed) did not work.  EWH---
23 months ago
Thank you for your replies, I guess I am more worried then anything about sti, even after having antibiotics. I haven’t had any discharge from my penis, but I’ve been feeling like it is itchy Or throbbing, I guess it may just be stress. I really don’t feel pain while urinating. I took the anzythromycin on Thursday and the suprax this last Saturday. How long does it take to clear or or resume having sex with my girlfriend after taking the medications? Am I still contagious now if I do have it?
Edward W. Hook M.D.
Edward W. Hook M.D.
23 months ago
I happened to be on-line when your reply arrived so you are getting a very rapid response  The odds are very high that you were not exposed to an STI.  Even if you were, the therapy you took would prevent/cure chlamydia, NGU, syphilis and virtually all gonorrhea. The symptoms you describe are not at all typical of any STI but they are the sorts of things anxious people notice when they are looking for any possible sign of STI.  They also are the sort of thing that tends to happen to people who take antibiotics without know what they are trying to treat.  

I will once again, urge you to stop worrying and move forward.  Although I do not see the need, if you must, you could test now- I am confident that if you do, the tests will be negative, indicating that no STI is present.  I see no reason for you to abstain from unprotected sex with your regular partner either.

As you know, this is my third reply and for that reason, this thread will be closed shortly without further replies.  I also see no reason that you should need to return to the Forum.  Repeat anxiety-driven questions may be deleted without reply or return of your posting fee.  We do this for your sake.  EWH
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