I have been taking daily PREP everyday around 18h00. This morning, I took her to the doctor for HIV testing. We got blood drawn for the HIV Elisa which is being done and results will be out tomorrow. However, on the way home, I got rapid self test kits for us both. I tested negative and she tested positive.

The doctor had indicated that chances of HIV infection are low from my exposure and that they’d be high if she was on her period or had a discharge. Which she didn’t. At my insistence, he then prescribed a single pill of HIV PEP for me to take as we wait for results. The plan being if her result would be positive, I just continue with the whole course for a month. 

I took the PEP pill around 17h00 today. My questions are: what is the chance that I may have been infected? Would it be advisable to have unprotected sex with any partner before completing my course? What are the chances of the Prep I was on working and should I take the doctor’s PEP until I finish it? 

What should I do with my PREP that I was taking? The brands are different. 

I also must mention that I had not indicated to the doctor that I was on daily prep. He will see us tomorrow when the ELISA results are out. 

The domaine of your email address suggests you are in a southern African country (which I won't name where HIV is quite prevalent. The advice of expert providers where you are probably is more valid than my own. They will better understand the risks and routinely advised tests, treatment, etc. Therefore I will respond in general terms, and advise you to keep working with your doctor(s).

You say nothing about your partner -- but the context suggests someone you do not know well and who might indeed be at high risk for HIV. However, I agree with our own doctor that the HIV risk is low. It sounds like the intent is to stop PEP if your partner's HIV test is negative. That makes sense to me.

As for sex with your regular partner, I would also advise following the recommendation of the physician managing your exposure and PEP. For sure you should not have sex with her until you know your new partner's HIV status. If she doesn't have HIV, you can safely resume sex at home.

Those comments pretty well cover your specific questions. 1) We have covered the chance you are infected with HIV (nearly zero). 2) It should be safe to have sex with your regular partner, but you need to wait for your new partner's test result and your own doctor's advice about PEP. 3) Assuming you do not need to continue PEP, but plan to continue to have sex with more than one partner, probably continuing PrEP makes sense -- but this also should depend on your own doctor's advice, based on his or her knowledge of HIV frequency etc in your geographic area.

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

HHH, MD

Does this change your risk assessment? The Prep, as I gather, should be effective at preventing infection by close to 99%? What I’m trying to determine is if Prep alone would have been more effective than a condom alone at preventing HIV infection. Also, what would be the effectiveness of pep which I started taking about 11 hours after the exposure? Also note that about 3 hours after the exposure I had continued with my prep as this was before the doctor’s visit.

He says chances of infection are practically zero if I take the PEP consistently. I plan on doing that. He also said I should not take alcohol. 

Last questions: 

1. Does alcohol interfere with PEP. 

2. If I was on PreP, why would PEP be necessary? I thought I could stop PreP 2 days after an exposure. I don’t intend to go against my doctor’s advice but, I just want to know the medical reasons that could be behind it? Is it because PreP is less effective or there could be questions over my adherence and it would be better safe than sorry? 

3. I’ve seen on the forum where you mention that condoms add little, if anything, to the protection that properly taken PreP gives. Is it safe to say PreP is as effective as a condom? 

This concludes my post. You may close it after your response.

1. No worries. Alcohol does not interfere with PEP.

2. I discussed this above. Indeed, PEP may be unnecessary, but there are no research data and PrEP is not quite as reliable. But your doctor is the one to discuss this with.

3. You have misunderstood whatever you think I said. I would never advise not using condoms just because of PrEP. You might be confusing this with advice for sex when a partner with HIV is on effective treatment,  with no detectable virus in his or her blood. This is irrelevant for partners who might have HIV and are not being treated for it. And of course condoms also prevent other STDs.