[Question #5725] Very Risky Exposure and PEP

73 months ago

Very troubled to write this. In a momentary lapse of reason, and fuelled by controlled substances, I made the biggest mistake of my life. I had unprotected sex with multiple csw’s in Mumbai’s red light area. I think it would have primarily been vaginal, but I do recollect attempting anal penetration as well. I cannot remember how long it lasted with each one (I don't think very long and I did not ejaculate). I did ask them if they had hiv or any problems, and I do recollect them saying they were fine. I started PEP within 19 hours and its been 3 days now. I do not have a doctor I am working with and got the PEP on my own.

From the research I have done, it seems the prevalence of HIV in Mumbai csw’s is 7.5% (some sources even go up to 50%). Since I am NOT circumcised, and if we just restrict to vaginal, the risk is 1/500, so the odds are 1/500 x 7.5/100 = 1/6700. And if 3 were involved, then it would be 1/2200. If I start looking at anal, then given risk is 1/160 for uncircumcised, for all 3 exposures total risk is around 1/700. Can you please help me with the epidemiology and risk?

I guess I really have only two choices – continue the PEP or stop and take my chances and find out earlier. As you can imagine, I am in a very bad state mentally and emotionally, but need to be logical now in my approach.

In your opinion, does PEP really work or are there just too many variables involved? And even if it does work, from archives I believe it is only 90% effective and its possible it can fail even if started early and adhered to as well. I guess what I’m asking is: (1) Would you have taken PEP if you were in my position, and (2) Does PEP really work or is it just a Hail Mary at this point and am I better off discontinuing it and taking my chances – seems like my only hope at this point is if all of them were HIV negative at the time!

H. Hunter Handsfield, MD

73 months ago

Welcome to the forum. Thanks for your question. You obviously regret these exposures, but don't expect advice or comments about that aspect. We don't moralize or otherwise judge peoples' behavior, unless there is evidence of unwanted or physically dangerous contact.

You have pretty well analyzed the situation, except that the average transmission risks are lower than you used. The average risk for a single episode of unprotected vaginal sex, if the woman is infected and not taking anti-HIV drugs, is around 1 in 2,500 (according to calculations by the US Centers for Disease Control and Prevention). It's around 1 in 900 for insertive anal sex with an infected partner. The risk is lower (usually zero) if on treatment for HIV. Also, be careful about data on frequency of HIV in sex workers. There may be data about 7.5% in parts of Mumbai, but such estimates are highly variable depending on where and how CSWs are recruited for such studies, and can vary dramatically even between one bar or brothel and the next.

So your risks start out correspondingly lower than you quote. Was PEP warranted? Probably yes, if indeed there are reliable data that up to 7.5% of CSWs have HIV in the area this happened; and with multiple exposures, including attempted anal. If these facts are true, then I definitely would take PEP if I were in your situation. And yes, PEP "really works", especially if started wtihin 24 hours of exposure (probably well over 90% effective) and probably highly effective out through 48 hours. Beyond that, it becomes less certain and PEP usually is not prescribed if it cannot be started within 72 hours.

Once PEP is started, almost always it should be completed for the full month of prescribed treatment. However, that is a decision for the patient and the doctor/clinic and I will not advise you on it one way or the other. You need to find a doctor or clinic with experience in HIV and its prevention and follow their advice. Do not stop PEP before that.

You allude to but don't go into detail about the main (and only) downside of PEP -- that testing for HIV must be more prolonged. If PEP doesn't work, it might delay blood test positivity, and most experts would test persons out to 3 or even 6 months. But in the meantime, don't panic. If we calculate the chance you were actually exposed, it's 0.075 x 3 x 0.0004 = 0.00009, or 1 1 in 10,000 -- pretty good odds. Even if PEP is "only" 90% effective, it would reduce your risk to 1 in a hundred thousand.

So based on what you know now, I think you made the right decision and now can kick back and not be freaked out over the next 3 months or so. In the meantime, find a doctor for in-person evaluation if her advice is different than mine.

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

HHH, MD

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73 months ago

Dear Dr. Handsfield,

Thank you for your reply. I believe the risk per incident figures you have quoted are for circumcised individuals? As I am not circumcised, it seems the risk is 5-8 times more (as per PEP guidelines in UK and Australia). Is this correct? If so, if we take a 5x risk, then the revised cumulative risk is 0.075 x 3 x 0.002 = 0.0005 or 1/2000 for vaginal and if pep is 90% effective, then 1/20,000 with pep. Does not seem very encouraging...and if we do this for anal, then its even worse - 0.075 x 3 x 0.006 = 0.001 or 1/1000 (or 1/10,000 with pep).

This is also without considering if they had an std which would make it even riskier. Speaking of which, the next morning, I woke up and there was white milky liquid around urethra witch scant thin white stringy material coming from urthera. I thought it was too soon for an std? However, by the next day, there was no further discharge, but the urethra was uncomfortable. I did prophylaxis of 2.5G azithromycin and 800mg cefixime thereafter. Do I also need to take tinidazole?

Looks like I'm in for a very long and stressful 3 months!

Thanks!

H. Hunter Handsfield, MD

73 months ago

I don't know where you're seeing 5-8 times increased risk from being uncircumcised. The accurate figure is double risk. So you can cut the risk calculations I provided in half. The increased risk from most STDs is in the same ballpark, probably around double for any single exposure. But even with your more pessimistic estimates, the odds remain strongly in your favor. I would suggest you staop searching the web on this -- like many anxious persons you seem to be drawn to information that enhances your fears and anxieties, and missing the reassuring information that also is present.

You took larger than recommended doses of azithromycin and cefixime, but they would have protected you sell against gonorrhea, chlamydia and syphilis. I would not recommend also self treating for trichomonas.

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72 months ago

Hi Dr. Handsfield,

Its now been 3 weeks for me on PEP - just 1 week to go. I suppose the real anxiety/stress will start once PEP is finished and I am awaiting testing. I am planning my post PEP testing schedule and wanted your thoughts on the same. The CDC says one should test 4 weeks and 12 weeks post exposure (BASSH say 4 weeks and 8 weeks is enough). My questions are:

1. If PEP delays the window period, then why do they even recommend a test at 4 weeks? Is there something I am missing here?

2. Would a PCR RNA at 6 weeks post exposure be equivalent to a Duo at 8 weeks post exposure? And are both of them fairly conclusive if negative? I would imagine if PEP was unsuccessful, then virus would be detectable in that timeframe? I know the official guidelines need to be conservative, so just wanted to know about more practical window periods.

3. Is it true that one cannot get any ARS symptoms while on PEP?

4. Will taking PEP longer than 28 days be more beneficial?

5. Is PEP failure due to late initiation and/or poor adherence, or does PEP fail for other reasons as well?

6. Is Hepatitis B or C transmitted by sex (vaginal and/or anal) or only blood?

Thanks for your time. I am just hoping for a miracle!

H. Hunter Handsfield, MD

72 months ago

You should follow the advice of the doctor or clinic where your PEP was prescribed about the schedule for HIV testing. Almost cerainly you to not have HIV. The odds you were infected were no higher than 1 chance in maybe 10,000. Since PEP is at least 90% effective, the chance you are infected despite that treatment is 1 in 100,000.

1. There are no conclusive data on proper testing intervals, and different clinics and doctors have different recommendations.

2. RNA testing at 6 weeks (2 weeks after completing PEP) will be very reassuring and I imagine nearly 100% conclusive at 8 weeks.

3. I've never heard of anyone having symptomatic ARS while on PEP and doubt it can happen. Again, no scientific data have been reported.

4. To my knowledge, there has been no study of longer courses of PEP. Since 4 weeks is nearly 100% effective, there probably is little or no benefit from longer treatment.

5. PEP failure is too rare to know the answers to thse questions.

6. Blood exposure is required for hep C transmission, but probably not for hep B.

You are NOT hoping for a "miracle". That implies you were at very high risk of catching HIV (you were not) and that PEP usually doen't work (which is wrong). You are hoping for the expected and highly probable outcome that you do not have HIV.

That completes the two follow-up comments and replies included with each question and so ends this thread. Please do not return with another question to post your test results if they are negative -- which they will be. All we will do is agree that the negative results are conclusive and reliable.

You are seriously overreacting to this situation. Do your best to settle down and stop worrrying. But I do hope the discussion has been helpful. All the science involved here is on your side and my replies throughout this long discussion were meant to be very reassuring. Please accept them in that spirit. You do not have HIV. If you continue to remain anxious, I recommend you go back and re-read all my replies above, and concentrate carefully.

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