Let’s Talk About PEP Pt. II

A Conversation with Dr. Ami Singh
Let’s Talk About PEP Pt. II
Dr. Ami Singh, Infectious Disease Specialist


When we looked at the data from the 2014-15 Edmonton Sex Now survey, based on 363 responses, we saw that only about half of them were aware of what PEP was. That’s significantly lower than what we saw for PrEP which is a much newer concept than PrEP. So, for those who don’t have a great understanding of what PEP is, could you explain it for us?

PEP is really a way for people who may have been exposed to HIV, to prevent them from getting HIV in the first place. How that is done is that the person needs to take HIV medications as soon as possible after the exposure has occurred; ideally we say within one to four hours of the exposure, but up to 72 hours after the exposure, and then the medications need to be continued for twenty-eight days after.

Where can someone access PEP in Edmonton? Can they come to the STI clinic or does it need to be one of the emergency rooms?

For most people, we’re asking that they go to the emergency departments. The STI clinic is able to offer PEP, but as you probably know, we do have a problem with capacity. People coming to the STI clinic may have to wait and then there may not be time for one of the nurses to see them. So in order to guarantee that the person is seen we are recommending that they go to the emergency departments. But if they do come here, and are able to get in, then PEP can also be started here.

If somebody gets assessed for PEP and it’s determined that they are eligible and they get a prescription, is that 100% covered similarly to a lot of other STI drugs or is there the potential that somebody may need to go through private insurance?

It really depends on whether they’re assessed to be eligible or not. If they meet public health criteria, as per the Alberta PEP guidelines, then what needs to happen is that the physician seeing the patient needs to get approval from the medical officer of health on call. If they agree that PEP is indicated, then the cost of the medication is covered for that person. Unfortunately, if it isn’t approved then it is possible the person may have to pay for the medications out of pocket.

If they’re not found to be eligible under public health criteria, could they still get the prescription, choose to go on it, and then go through their private insurer?

Yes, absolutely. They can get a prescription from their prescribing physician and fill the prescription if they have coverage or are willing to pay for it.

I did look at the Alberta Health PEP guidelines. And I also reviewed the new draft Canadian guidelines on PrEP and PEP. In those guidelines there seems to be more of the understanding of what we now know about an undetectable viral load and whether or not we’d consider that somebody had “transmissible HIV”. That seemed to be an element that was considered more in those guidelines than what I saw in the Alberta Health PEP guidelines. Now that it’s becoming an emergent view among many top tier medical professionals in the field of HIV that an undetectable viral load essentially means non-transmissible? Again, not everybody is there yet. But it seems we’re shifting more towards that understanding. Do you see a day – maybe even now – that our guidelines should evolve to reach that understanding?

I believe the last draft of the Alberta guidelines were prepared in early 2015 and since then further information has come from the PARTNER Study confirming that the risk is very low and they observed no linked transmissions in this study. But you’ll notice that even in the PARTNER Study, the authors are not saying that the risk is zero. They have stated that there is always a margin of error (reported as confidence intervals) and the upper limit of the confidence interval for this study is 4%, meaning that there is theoretically up to a 4% risk of transmission per year via receptive anal sex with an partner with an undetectable viral load. If you read the background in the Alberta guidelines you’ll see they say they’re awaiting the final report of that study, which is actually expected sometime in 2017, before they make more definitive recommendations. I was a bit surprised that the national group wanted to be so definitive right now. I could see us saying that in a few months when we see the final published data from the study.

When you start to see some of these new consensus statements from very well respected people in the field of HIV who are now saying that even though we still haven’t gotten to zero transmissions with the data they are confident in saying that if somebody is truly undetectable they’re HIV is not transmissible… Do you think that’s jumping the gun a bit?

I think that’s where things are heading. I’m just not sure that everyone is willing to make that leap without the final study data being available at this point. Probably within a year or two people will have a higher degree of confidence to make more formal recommendations.

So, I have another job at HIV Edmonton. And sometimes you get people calling in after they’ve found out about PEP somehow through googling or through the HIV Edmonton website and they want to get it. And so, of course, I can’t give official advice and what not but often they’re telling me about what’s happening, and with the knowledge I have I get thinking about the risk factors and often they’re actually quite low. And I do have questions in my head as to whether or not they’d qualify. From your perspective, is there a way to, first of all, ensure that people do know what it is, because I believe they have the right to know what’s available to them, but also ensuring that a bunch of “worry-wells” aren’t necessarily…

You know, those are the situations typically where PEP wouldn’t be approved (that is the costs covered). We’ve had some guys come in and say, “Okay, I think I had sex last night but I’m not really sure ‘cause I was kind of out of it, and even if I did, I am not sure if the other person would have used a condom,” and so you don’t even know number one: did any type of sex occur. But if it did and they want to take PEP, those types of situations wouldn’t normally be approved. The criteria are in the guidelines. Basically, if you’ve been either top or bottom with a known HIV positive partner [and something happened where you may have been exposed to HIV], regardless of reported viral load, you would get started on PEP. Then you’d see the Infectious Disease Specialist who would review in more detail what you know about the HIV-positive partner, such as viral load, etc. But, say, in the case of unprotected oral sex, it generally wouldn’t be approved.

Okay, that’s interesting because a lot of the guidelines come down to the “source”, or the HIV-positive partner, which I mean…

You often don’t know right?

Well yeah, exactly! So how do we, in your opinion, square that with our understanding that the majority of new infections in Canada and the US can be attributed to people who are unaware of their status. So is that something that PEP can’t really solve? Because the majority of people probably aren’t having that conversation with their partner beforehand, so what happens when they don’t know?

What would happen is if they had an encounter where a man who has sex with other men, because there are so many new infections right now in that population, simply by virtue of having had such an encounter we’d consider them higher risk regardless of the source’s HIV status, or whether their status was known HIV positive or not. We’d consider them eligible for PEP.

This kind of touches a bit on PEP and also on testing window periods. Sometimes I feel like the answers vary a bit and in Alberta can sometimes be on the more conservative side of one month. I know in Vancouver they’re using different types of testing in some circumstances and that the window periods they’re giving are a bit lower. So, I asked someone within Vancouver Coastal Health specifically what window period they give people who might have been exposed to HIV. And I was told they don’t give them a window period; if someone thinks they’ve been exposed to HIV, they should go get assessed for PEP. And form the same survey I references earlier, in the Vancouver sample, there was a much higher awareness of PEP than in Edmonton. So, do you think we need to do a better job at referring people to get assessed for PEP here in Alberta?

In addition to lack of awareness on the part of the person seeking care, we also have a problem with lack of awareness by physicians as well. Many physicians may not be aware of the criteria for PEP so that is a challenge right now. You really should be assessed and I know if they came to the STI clinic and the person was eligible they would get it. The problem is trying to get in here. The clinic has done a number of things to improve access but this remains a challenge.

That is, I think, a part of the conversation now that I’ve been having. We look at things like Sex Now and we saw that about forty percent of respondents hadn’t received tests for either HIV or STIs in the last year. So, even if we could get the other forty percent in the door you literally couldn’t test them. There aren’t the capacities or resources. So, we definitely need more primary health care providers to get on board.

Absolutely. We need to improve access somehow for testing. But you asked about the window period; so we screen in Alberta with a fourth generation HIV test. The window period for that is between fifteen to twenty days. Theoretically, if the person has not been on any antiretroviral medication (HIV medication) within fifteen to twenty days the test should be positive.

If somebody didn’t get on PEP, and they feel there might have been a good chance of transmission) then would you say come here in fifteen days?

I’d get a test done right away, see where they’re at and get one repeated. If they’re able to wait I’d wait a month before repeating the test, depending on their level of anxiety.

So, you’d say to get a baseline because – is that the understanding – that if you’ve had this one experience you probably may have had another experience before, so let’s just find out your status right now?

Exactly. It’s good to get a baseline test. That also helps you to determine if they did become positive as a result of that exposure, or if they’re already positive.

You recently sent me a study as I had asked you a question about this… but if somebody goes on PEP, and it’s not successful, could that delay HIV infection, meaning that they would need to continue following up for HIV testing to a later date?

The bottom line is that the paper suggests yes. The question is how long. With this paper, it suggests for patients taking HIV medications, it could take up to six months for the test to become positive. So, if you’ve taken PEP or PrEP and you’ve had an exposure, what I’m thinking is we’re going to have to recommend at this point that the last follow-up test be done at six months, or an RNA test be done earlier. But getting that RNA test done earlier will mean having to see a specialist or have a specialist involved somehow.

We seem to be floating numbers in the eighties around as it relates to PEP efficacy based on this studies done quite some time ago..

Yes, that’s about how much the risk reduction is.

But I hear that it’s probably much more effective but that there’s not really an ethical way at this point to continue doing studies on PEP. Because I’m sure you can’t, say if someone came in who’s been exposed, give them a placebo…

That’s exactly right. Most of the information we have on the efficacy of PEP comes from occupational settings where the source was known to be HIV positive. They followed mostly healthcare exposures. The efficacy also been extrapolated from other settings such as reducing mother to child transmission of HIV. So if you take all that information combined it reduces the risk of transmission by about eighty percent. But let’s say you get a needle stick from a known HIV positive source that has a high viral load, and the needle penetrates the skin and blood gets injected into you, your chances of acquiring HIV from that type of exposure is estimated to be 0.25 percent. So if you take PEP it reduces your risk by eighty percent and has taken it down to a very small fraction of 0.25 percent. All that’s happening is that it’s getting you closer to zero but we never say that PEP gets you completely to zero. Although, essentially that’s what it is. It’s pretty darn close to zero.

At the end of the day, we can say that PEP is very effective at preventing HIV infection, no?

It is very effective. The other thing is that those earlier studies in occupational and mother to child transmission circumstances used only one or two drugs. Now, as a standard, at minimum we use two drugs and often three drugs depending on how high-risk the exposure was.

We’re talking about PEP today but of course we see other opportunities like PrEP, the 90-90-90 strategy, upping access to testing, etc. But in this economy, of course, there are constraints. So we can’t up things to the degree to which we would like to. Looking at our options such as expanding access to PrEP, really working on that treatment as prevention spectrum, and something like PEP, while knowing that there are limited resources… Is there an area in particular that you invest in more from your perspective?

I think I would like to see us taking a combined approach to HIV Prevention. I don’t think we can focus on only one intervention because no single intervention will work by itself. A colleague of mine has been looking at patients who are out of care as part of a project and so we list of patients who have not accessed care in the last year that we know are positive. So, we’re trying to figure out a way to get them back into care. We need to look at how we can improve access to testing and also access to PEP and PrEP. I really feel very strongly that we need to be offering PrEP. We are already offering PEP but as you mentioned people may not be aware that it exists and how to access it. But we definitely need to figure out how we can get PrEP off the ground while focusing on how to improve all of these other areas at the same time

Since one of things we were talking about is cost and available resources and whatnot, do you believe that we can offer PrEP, ensure more people know that PEP is available, and save money?

I think in the long run, yes. There is data showing that these interventions are cost-effective. The lifetime cost of an HIV infection when balanced against the costs you would invest in preventing infections… these interventions have already been shown to have been cost effective. We need to focus more on the long term.

But last question… Thinking of the future of sexual health more broadly in Alberta, from your perspective as a medical professional, what do you think are some of the biggest concerns we have coming down the pipeline, and what do you think are the biggest opportunities?

That’s a tough one. Probably one of the biggest challenges will be how do we try to get a comprehensive plan in place and work with affected communities to implement that plan. I really do think we need to take a combination approach not just around HIV but STIs as well. We need to think in less traditional ways both in regards to improving access to testing but also access to treatment as well. Some very novel approaches have been taken in other parts in the country and I think we need to strongly consider implementing some of these approaches in Alberta. If I’d like to see something come out of the new STBBI strategy, I’d like to see newer ways to tackle the issues.