[Question #5799] Unprotected vaginal HIV and STDs

73 months ago

Dear doctor, Im male 30 yrs. recently I engaged into unprotected vaginal sex. On the following day I went to a clinic and they gave me PEP. They also gave me azithromycin (pill)+ ceftriaxone (intravenous) as prophylaxis.

Even with the prophylaxis 2 days later I had some yellowish discharge, I went back clinic on that same day and they made me repeat only azithromycin. On the next day discharge became much less and continued to decrease even more the following days. Few days later with still little tiny discharge I went to doctor who gave me ceftriaxone (intramuscular) and asked urine PCR exams for thichomonas, Chlamydia, gonorrhea, mycoplasma hominis and ureaplasma urealyticum. All came back negative.

My questions are:

- What is my risk for HIV taking PEP (starting around 20h after exposure) taking into account the vaginal exposure that lead to some discharge.

- The negative PCR results are conclusive? Is there any chance a false negative because I made it the same day I took 2nd dose of ceftrexione? Did I have to await?

- these antibiotics that I took, would kill potential syphilis?

- how long is a reasonable window time after exposure that would appear symptoms of other STDs (other than hiv hep b/c and syphilis) if I catch them?

Many thanks!

H. Hunter Handsfield, MD

73 months ago

Welcome to the forum. Thanks for your confidence in our services.

There are peculiar aspects to your story. I'm guessing you're in China, or maybe Japan or Korea: I don't know anywhere else likely to use IV ceftriaxone in this situation. I'm also not aware of many situations what would warrant anti-HIV PEP in this situation -- but perhaps the setting or your partner suggested especially high risk. But a single vaginal sex exposure rarely warrants PEP, even unprotected -- unless the female partner is know to have HIV.

As for urethral discharge 2 days after exposure and immediate treatment with ceftriaxoe and azithromycin, I have no good explanation. Chlamydia, Mycoplasma genitalium, and other known causes of nongonococcal urethritis (NGU) don't cause symptoms sooner than 7-10 days. Gonorrhea can do so, but even in that part of the world, gonorrhea bacteria so resistant to ceftriaxone are very rarel. (By the way, M. hominis and U. urealyticum are normal genital bacteria and rarely cause symptoms at all. Testing for them is not normally done in expert STD clinics in most countries.) But if your discharge has now cleared up and does not reappear, you were cured and no further worries.

To your specific questions:

1) PEP against HPV, started within 24 hours, is thought to be highly effective. Given both the low risk of vaginal sex for HIV (average 1 chance in 2,500 if the woman is infected) and the effectiveness of PEP, you needn't be at all worried about HIV.

2) The negative tests for chlamydia etc probably are highly reliable, although I cannot comment on specific tests used in your location.

3) Ceftriaxone definitely would have prevented syphilis if you were exposed to it.

4) I would not recommend testing for other STDs. But if you decicde to do it, the blood tests for hepatitis B and C are conclusive after 6 weeks, and HSV after 3-4 months. However, you definitely should not be tested for HSV. The tests are not sufficiently reliable and often give uncertain results.

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

HHH, MD

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73 months ago

Many thanks for the fast reply! I’m at Latin America. Her hiv status is unknow. I think they were extra conservative here. Your reply was very helpful. Only a last question for the sake of clarity: in question 2 I’m not questioning the sensitivity/reliability of the test itself. My concern is, considering the test here is reliable, could taking the 2nd dose of ceftriaxone at the same day of the test “mask” the result? I mean, could the medicine make some sort of immediate effect just enough to make result negative but than latter on some residual grow again? Or this assumption is only my mind starting to be very anxious creative? I’m asking this because when I took 2nd dose of ceftriaxone the doctor asked to wait 5 days to test, but my anxiety made me test at the same day.

Would you recommend Chlamydia and/or Gonorrhoea test after few days again?

Thanks.

H. Hunter Handsfield, MD

73 months ago

I agree your doctors were being very (overly) conservative.

Antibiotics do not alter test result reliability in the way your question implies. The standard tests detect DNA, which persists for more than a week even after effective treatment. Your tests reliably show you did not acquire gonorrhea or chlamydia. There is no point in repeat testing.

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73 months ago

Dr, understood. Many thanks! Great service you provide here.

H. Hunter Handsfield, MD

73 months ago

Thanks for the thanks. I'm glad to have helped. Take care and stay safe.---