Behind the Science: Antimicrobial Resistance and Sexually Transmitted and Blood Borne Infections: Healthy Canadians podcast episode 4

Transcript

Transcript

[music]

Madeline Poplett (Host): Hello and welcome to Healthy Canadians: Behind the Science, where we get science-specific about the health topics that matter to all of us living in Canada. I'm your host, Madeline Poplett.

On last week's episode of Healthy Canadians, we heard from with Anna-Louise Crago, Senior Epidemiologist with the Public Health Agency of Canada, about antimicrobial resistance or AMR. Today, Anna-Louise is back to talk about the links between STBBIs, otherwise known as sexually transmitted and blood borne infections, and AMR. But first, a word from us.

Healthy Canadians is brought to you by Health Canada and the Public Health Agency of Canada. We aim to give you information and perspectives about the health topics that matter to all of us living in Canada. What we discuss won't always reflect the official positions or policies of the Government of Canada, but that's okay. These are conversations, not news releases. Okay, we've got lots to discuss today. Let's talk about antimicrobial resistance and STBBIs.

Madeline: So, welcome back, Anna-Louise. You've spoken to Megan about antimicrobial resistance, what that is, the human impact. There's a lot of history as well. For any listeners who are jumping in perhaps just on this episode, could we take a moment to kind of define again what AMR is and its role with us as people?

Anna-Louise Crago: Absolutely. So, to explain, in short, what antimicrobial resistance is: It’s when a microbe develops a way to protect itself from the antimicrobial, so the medicine that would be used to try and kill the microbe or to stop it from growing. And fundamentally, what that means is that if a microbe develops a resistance, it can become much harder to treat, much more complicated to treat. It can take longer to treat. It can be much more difficult as the patient, if it's becoming more complex to treat. And worst of all, in some cases, it can become untreatable.

Madeline: Okay. So, there's a relative issue not only with bacteria, but the fact that they can then become resistant. So, we're speaking about that. I do know that within the realm of illness, STBBIs are something that people in Canada may or may not encounter throughout their life, and I understand that there is a tie between AMR and STBBIs. Before we get into that, could you please kind of define what an STBBI is? Maybe people have referred to these types of illnesses with other terms, so we could potentially clarify that before we go forward?

Anna-Louise: Sure. So, STBBI stands for sexually transmitted and blood borne infection.

Madeline: Okay.

Anna-Louise: I'll be focusing primarily on sexually transmitted infections today, but blood borne infections can be things like HIV, and HIV can also be sexually transmitted or blood borne, and sexually transmitted infections can be viruses. They can be bacteria. So, in the viral category, we have things like HIV, and in the bacterial category, an example would be gonorrhea or chlamydia or syphilis.

Madeline: Okay. So, it's an acronym that can encompass a variety of these illnesses or infections. Specifically with AMR, could you speak to the link between AMR and STBBIs or sexually transmitted infections?

Anna-Louise: Right. So, antimicrobial resistance can happen to all different kinds of microbes, and we know that resistance to certain first-line treatments can be an issue for certain viruses and antivirals like HIV, but I'm going to focus in more on bacterial sexually transmitted infections and antibiotics.

Madeline: And that's where AMR really becomes a concern, related to those things.

Anna-Louise: It becomes a concern for some of them. For some of them, it is not a current concern, and for other infections, it's a real concern because we're facing the prospect for some infections that in the next decade, they may become untreatable with the antibiotics we currently have.

Madeline: I see, I see, okay. So, Anna-Louise, how common would you say the STBBIs are that require antibiotics?

Anna-Louise: So, there are a number of bacterial STIs, sexually transmitted infections that can require antibiotics.

Madeline: Okay.

Anna-Louise: And some of the most common ones are chlamydia, syphilis, and gonorrhea. So, chlamydia, we saw (in 2020) 105,000 reported cases in Canada, around 31,000 cases of gonorrhea, and about 9,000 cases of syphilis. So, these are very common infections, and there's been an increase in those infections more or less over the past 20 years. There's many different concerns and considerations about those infections but I'm going to zero in on drug resistance for a minute. So, if you look at something like syphilis and chlamydia, they're not the infections where we're the most concerned about drug resistance, but it's still something that's important to keep in mind. So, chlamydia, first of all, drug resistance has not been found stably in humans for chlamydia.

Madeline: Okay.

Anna-Louise: So, that's reassuring, although theoretically, it could emerge. So, we have to keep an eye on it.

Madeline: Keeping an eye on it. I think that's important for sure, yeah.

Anna-Louise: For syphilis, in terms of drug resistance, we still have antibiotics that are very effective at treating syphilis, but we have lost some due to resistance.

Madeline: I see.

Anna-Louise: So, erythromycin and azithromycin are treatments to syphilis that developed resistance over time, and even though we have treatments that work for syphilis like, for example, penicillin G, or in some instances, doxycycline, sometimes there are world shortages of the treatment that we need for syphilis. So, on a global scale, it is a concern to not have a wider array of antibiotics available to treat it.

Madeline: Absolutely.

Anna-Louise: When you get to gonorrhea and mycoplasma genitalium, another bacterial infection that is not reportable, so we don't know how common it is…

Madeline: It’s hard to capture the scope at that point.

Anna-Louise: Yeah, the picture changes completely.

Madeline: Okay, okay.

Anna-Louise: So, we know for mycoplasma genitalium, from studies done in sexual health clinics, that when people go in for testing, it's one of the most common infections that they have. So, we know it's prevalent, and with both gonorrhea and mycoplasma genitalium, there is resistance to a number of classes of antibiotics. So, gonorrhea has become resistant to almost all of the classes of antibiotics that have been used to treat it, from penicillins to tetracyclines. And depending on the context where you were in, there's one class or potentially a combination of classes left to treat it.

Madeline: Wow, okay. So, the catalogue is kind of being run through in terms of options for gonorrhea at this point.

Anna-Louise: Yeah, and the World Health Organization has warned that gonorrhea risks becoming untreatable with the antibiotics we have in the coming decades, if we don't find other ways of responding to it.

Madeline: My goodness, okay.

Anna-Louise: And also, in the scientific literature, experts in mycoplasma genitalium similarly rung the warning bell that mycoplasma genitalium may, in the not too distant future, become untreatable if we don't address how resistance is galloping in mycoplasma genitalium. Another infection that is concerning is Shigella, or what is called XDR Shigella or extensively drug-resistant Shigella.

Madeline: Wow, okay.

Anna-Louise: Which usually means… different jurisdictions have different definitions, but resistant to five classes of antibiotics.

Madeline: I was going to say, I feel as if that's not a title that's given out with a light hand.

Anna-Louise: No [laughs].

Madeline: It has to be serious.

Anna-Louise: That’s correct. And so, there's been global interconnected outbreaks of XDR Shigella, and there are some cases in Canada, and of sexually transmitted XDR Shigella. And generally speaking, from my understanding, Shigella, it often clears within five to six days and doesn't necessarily need antibiotics, but it becomes more concerning if you have a very severe infection or if you're immuno-compromised. In those cases, not having a repertoire of medicines to be able to treat it as an option is really difficult, because then, treatments sometimes involve very heavy drugs and can become very complicated for longer-term recovery.

Madeline: So, I think based on what we've already discussed, I feel like it's difficult to pin down one thing or another. There's a lot of nuance. But access to care, particularly to treatment, seems to be a contributing factor, of course. Is that something you can speak to in a bit more detail?

Anna-Louise: Yeah, it's a very complicated situation. So, the first thing I would say from the outset is that when communities or groups of people are disproportionately affected by AMR and STBBI AMR, many factors can be in play, and there are many historical examples of communities that had very high burdens of infection and then had high levels of antimicrobial use for treatment, often exactly as prescribed, and then high transmission within the community.

Madeline: I see.

Anna-Louise: And that can contribute to the emergence and the spread of AMR. So, the first thing I just really want to highlight is that because a community is disproportionately affected by AMR or by AMR STIs does not mean they did anything wrong.

Madeline: No.

Anna-Louise: It does not mean they are to blame. Often, it is happening in communities who are (inaudible) a very proactive approach to their health, and if anything, it highlights the key role in what we need to look at, you know, questions we need to ask about, what could community prevention of AMR STIs look like? How can we think? And these are questions coming up in the scientific literature more and more. How can we think holistically about treating and preventing STIs and also addressing AMR together? And what does this look like on the individual level, on the population level, but also on the key affected community levels?

Madeline: Yes.

Anna-Louise: So, we have so many questions and we're only just barely starting to come up with answers to them.

Madeline: It's nuanced for sure. There's so much to discuss when it comes to just all of that variety of components, kind of bringing together for solutions. I know when it comes to AMR, a be-all-end-all solution is not what's on the horizon, but I'm sure in your line of work, there has been promising research or anything that you could speak to in terms of next steps with AMR as a whole.

Anna-Louise: Absolutely. So, one piece of promising research that links in to this whole access to care piece is that in many remote locations, it's really difficult to get what are called susceptibility tests, so if you have a gonorrhea infection, to get a culture which is often also not (inaudible) much more invasive, and then have it analyzed in a laboratory to find out, like, what medicine would your gonorrhea infection respond to, and which ones would it not, to make sure that the treatment is really targeted and you're getting the right drug to the right bug, but that is a lot harder to access in a lot of places. And so, potentially getting the wrong medicine or in the wrong dose for your infection is potentially contributing to AMR at some of these places. And so, what that underscores too is that we're trying to bring together all the science and technology to respond to AMR, but we have to deal with how it can be inequitably accessed. We have to try and find solutions to that as well. And so, one really innovative solution that's being developed at the National Microbiology Lab is looking at whether we can take what are called NAATs, which are the tests that are less invasive done instead of cultures for gonorrhea.

Madeline: Okay.

Anna-Louise: Usually based with, based on urine samples.

Madeline: So, it's a separate approach.

Anna-Louise: So, it's the approach that's done in places that can't do the lab.

Madeline: Okay.

Anna-Louise: So, it’s the approach that gives you less information on AMR, and that's part of the problem, but they're trying to see, with the remnants left from those NAATs, if they can predict, use incredibly innovative ways of predicting what the infection might be resistant to. And so, that's a really interesting example of a new approach to technology that could help to reduce some of those inequities and to better target treatment. And so people have access to the right treatment for their infection, which is important not only for them and their infection and their health but also for...

Madeline: Reduction.

Anna-Louise: Of course.

Madeline: Of course.

Anna-Louise: And some of the other really promising things, but we're waiting to see because the results are not in from the studies, are using vaccines to prevent different infections that have acquired resistance, and this has been done not for STIs but for other infections, but there are ongoing randomized controlled trials looking at could this be an effective vaccine for gonorrhea?

Madeline: Okay.

Anna-Louise: Or what would its effectiveness be? And there's interesting research looking at, like, what could an effective vaccine for gonorrhea look like? And that's a really interesting approach to reducing AMR by reducing infections, and it gets at that whole piece of trying to tackle both the prevalence of STIs and the AMR together.

Madeline: A dual solution in some ways.

Anna-Louise: Yeah, and then there've been really interesting social and health interventions where people have talked to communities that are disproportionately affected by some of these resistant infections, and looked at what can happen if we do community education within the community about these, and start to think and strategize about how to respond as a community. And so, that's also a really exciting novel approach to some of these things. I will say there are also many other novel approaches to AMR that are not about STI AMR but other kinds of infections in AMR, and one I think I just really need to flag is phage therapy, and phages are these viruses that can be used to target very specific bacteria.

Madeline: Okay.

Anna-Louise: And that can be really helpful, their ability to really zone in and target. At the same token, it has made it extremely difficult to develop phage therapy because you are trying to find a very specific key to a very specific door.

Madeline: However, if it's showing promise in that way, you know, the exploration is happening, you're saying, it's nice to see maybe there is a very specific key and a very specific door that we can find for that. So, that’s very, very interesting.

Anna-Louise: Yeah, and the connection that I would make there to STBBIs, is that one of the pioneers of phage therapy, Steffanie Strathdee, has also been a pioneer of research on STBBIs in Canada and globally.

Madeline: So, there's a link there for sure.

Anna-Louise: So, there's a link even though it's not necessarily phage-to-STBBI link.

Madeline: I think that it's still really eye-opening to know that these potential solutions are being pursued and researched. Things take time but it is reassuring to hear from you that there are alternative approaches potentially coming down.

Anna-Louise: Yeah, there's a lot of promising work that's happening.

Madeline: Yes, that's a great way to phrase that. Well, I think that we could expand for quite some time on everything AMR, but I do believe that listeners’ interest will be piqued. They're going to want to check this out. So, if you could recommend a resource for people in Canada to learn more about AMR, where would you send them?

Anna-Louise: Well, the Government of Canada, the canada.gc.ca website does have really great and accessible resources dealing with AMR, also dealing with STBBIs and some dealing with drug resistance and concerns around drug resistance, specifically in STBBIs. So, there is a great infographic available that explains the latest findings around drug-resistant gonorrhea in Canada.

Madeline: And that can be found on canada.ca. They can search on canada.ca and find this type of resource, including this infographic.

Anna-Louise: Absolutely, and the way I find them is that I actually just go into the search bar and I plug in the terms I want and…

Madeline: Simple.

Anna-Louise: There you go.

Madeline: Great. Well, thank you so much for sharing your expertise with us today. Like I said, we could talk for much longer about this, but maybe one day in the future, we'll have you back to chat about this. This is fascinating, and thank you for the work that you do. It's been wonderful to learn. So, thank you for your time today.

Anna-Louise: It's a pleasure.

Madeline: Thanks for tuning in to Healthy Canadians: Behind the Science. If you're watching on YouTube, don't forget to click the ‘Like’ button below and subscribe to stay up to date on future episodes. Find us wherever you get your podcasts, and leave us a review if you like what you heard. For more information on the health topics that matter to you, visit canada.ca/health.

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