Malaria Prevention: Insights from Dr. Ross Boyce
Advancing Malaria Control and Prevention
Dr. Ross Boyce from the University of North Carolina Medical School shares his experiences and challenges in fighting malaria. His career, shaped by his time in the Army and medical training at UNC, now focuses on innovative malaria control strategies in Uganda.
In this interview, Dr. Boyce shines the spotlight on the state of malaria. Currently, half of the world's population is at risk of contracting malaria, with the most tragic impact being the high mortality rate among children under five, accounting for 90% of global deaths caused by the disease. This stark reality underscores the urgency of continuous research and sustained funding to combat this life-threatening illness.
In 2024, Dr. Boyce continues to lead groundbreaking efforts in the battle against malaria, thanks to a substantial $4.4 million grant from the NIH. This five-year project aims to implement a dual approach in Uganda, where heavy flooding often leads to spikes in mosquito populations. Dr. Boyce's team is set to evaluate the effectiveness of chemoprevention pills combined with larvacidal water treatments. Following a successful "proof of concept" study, these interventions are expected to commence in 2025, targeting over 35,000 children who are at heightened risk.
Dr. Boyce also tackles common misconceptions about malaria, providing crucial public education. He highlights the evolving challenges in malaria prevention, noting that mosquitoes are adapting to traditional protective measures, such as bed nets, by altering their feeding times. This behavioral shift makes it more difficult to control and prevent the disease using conventional methods. Furthermore, he points out the worrying trend of emerging resistance to malaria treatments in regions like Southeast Asia and Africa, posing significant hurdles to eradication efforts.
To combat these challenges, the new initiative spearheaded by Dr. Boyce focuses on long-acting preventive medications for children in Uganda. This strategy not only directly protects those treated but also reduces the overall malaria parasite prevalence in the community, thus providing indirect protection to the broader population.
Dr. Boyce’s efforts highlight the need for continued innovation and dedication in the fight against malaria. As he leads his team through this critical project, it is a reminder of the ongoing necessity for global collaboration and support to eradicate this deadly disease. Additionally, Dr. Boyce offers advice on personal protection for travelers heading to regions where malaria and other mosquito-borne diseases are endemic, underscoring the importance of proactive measures in individual health safety.
In summary, Dr. Boyce’s contributions to malaria research and prevention are invaluable, especially as he navigates the complexities of mosquito adaptability and treatment resistance. His work exemplifies the kind of determined, innovative efforts required to achieve substantial progress in the global fight against malaria.
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Transcript of the Interview
Mary: Hi, this is Mary with Insect Shield and I'm super happy to have Dr. Ross Boyce with me here today. He is a professor at the University of North Carolina Medical School, specializing in the division of infectious disease. Welcome, Dr. Boyce.
Dr. Ross Boyce: Thanks for having me.
Mary: First, if you could just give us an introduction, tell us about yourself,
Dr. Ross Boyce: sure, I am. I grew up outside Winston Salem, which I know is not too far from Insect Shield, but I ended up doing my after some time in the Army, I went into the medical field and did my medical school here at UNC and then went up to Boston to do my internal medicine residency training before coming back down here to set up shop.
During that time, I started working mostly in Uganda around malaria in the western and rural parts of that country where malaria is a big problem. And I've been working there now for the past 10 years on trying to control and prevent malaria in that area. Rural areas.
Mary: Okay. Wow. So there's a lot there. I know we've worked with you at Insect Shield with tick borne disease, so you But so malaria is more, that's your specialty, but you work in the all the different vector borne disease.
Dr. Ross Boyce: I do. Yeah, we are fortunate to have malaria here in North Carolina. And so when I'm here, a lot of the principles are the same. And so I certainly focus on tick borne diseases here in North Carolina as well.
Mary: Gotcha. Really, we wanted today to concentrate on malaria because coming up Thursday is World Malaria Day. I think, obviously a lot of talk comes back to malaria, as you mentioned. In the U. S. We don't worry about malaria very much, unless maybe we're going only if we're maybe going abroad for travel or for work.
And one thing I was noticed, I was reading that half of the global population is at risk for malaria. So really, everyone should be concerned about malaria.
Dr. Ross Boyce: Yeah, certainly. The map of malaria pretty much covers most of the middle of the earth, for lack of a better way of looking at it. The tropics whether you're in Asia, Latin America, Africa, and, Caribbean as well. And as we've seen, as the climate's changing a little bit even some recurrence down in Florida and our southern border this past year.
Mary: Yeah. Yes, we saw that. So I guess that is the question of what's the state of malaria in 2024. I just, why start working with Insect Shield back in kind of 2003, 2007 we would talk a lot about malaria, but then in the U. S. as more tick borne disease came about, that kind of became our topic, because we can obviously help a lot of folks here, but it feels a little bit like, I don't know, maybe not in your world, but some, it's like malaria has now It's not getting quite the attention that maybe it got for a while.
I know every once in the You hear, you know in the news it pops up. Oh, there's a vaccine potentially coming The gates foundation obviously doing a lot of work. What do you in your net last, Years working in the malaria. What do you see as like the state of malaria right now?
Dr. Ross Boyce: Yeah, I think maybe in the early 2000s and even into the teens, there was a lot of excitement with investment in malaria happening and we were rolling out bed nets and some new treatments were coming online. And I think there was a lot of optimism, which fed investment, which fed more for
interventions, which fed good outcomes, which, a virtuous cycle there. I wish I could say that kept happening. So we started to see some trends one of which was more and more mosquitoes that showed resistance to some of the things that were being used, whether it was the insecticide in the bed nets.
We saw mosquitoes start to get smart, I guess would be one way. And that They've changed how they feed. So traditionally, the mosquitoes would rest in the house and wait for you to go to bed and then bite you while you're asleep. But with nets being so common, it seems they've evolved to learn to bite early in the morning when you first come out of the house or early in the evening before you go to bed.
So some of those interventions that used to be key to what we've been how we prevented malaria just don't work like they used to. And then of course there's been this not wholly unexpected, but perhaps faster than we thought development of resistance to some of the treatments that we use that first started in Southeast Asia and is now spread to the African continent, which is certainly concerning.
And so there's been some backsliding that's happened. And I think that again, negative or more negative perspective makes donors less excited to donate to the global effort to reduce and eliminate malaria. And COVID happened, right? COVID made it harder to get nets out into the field.
It made it harder for people to get into treatment. And so I would say While things like the vaccines are exciting, they're far from perfect, and they still need a lot of work, there's a great sort of base to build upon, but in some of these other areas where we thought we'd achieved a lot, things are not quite looking as positive as they used to.
Mary: So if things were maybe going on a slightly down or are you coming back up to more cases, going back to levels that you'd seen before all of those things were working?
Dr. Ross Boyce: Globally, maybe they haven't changed. They haven't changed as a top line number, but certainly in some of the worst places like Congo and where I work in Uganda, we've seen the numbers creep back up again, which is worrisome.
Mary: Yeah. So I'd love to just talk more about your work specifically. Because it's something that, like we can hear an actual, concrete thing that's being done. So I was, saw that you back in what, Last September, we awarded a 4.4 million five year grant to, and I'll quote this, evaluate the effectiveness of a chemo prevention effort designed to prevent malaria outbreaks after flooding.
And you had to do a proof of concept to get that. So what does that all mean and what have you done and what are you going to do with all this this money in this five years?
Dr. Ross Boyce: One of the things that we observed at our site is it's for lack of a better term, it looks a lot like Western North Carolina. You've got hills, and valleys. And with a changing climate, Of course, you can't you can't assign any single event to climate change, but we've seen more frequent and more severe flooding happening at our site.
And when it floods because of the heavy rainfall, you end up with infinite numbers of pools of standing water. And that is a vacation spot for the malaria mosquitoes. They love that. And that probably, the pathway for that to happen is that you get more mosquitoes laying eggs in those pools of water that are closer to households, more mosquitoes emerge, they bite more people.
And so we tend to see this surge of malaria after these events. And one of the things that When this happened for the second time in ten years, it's almost an annual event now, we said we just can't keep watching this happen. We studied it the first time, the second time we said let's do something.
And so we got out into one of the villages where we work, and we gave the kids a medicine that's normally used to treat malaria. but it also has a really long half life. And because it sticks around in the body long enough, what it essentially does is it keeps those kids from getting malaria for anywhere from three to four weeks.
And we gave them doses of this once a month for three months after the flooding. With the idea being, maybe we can just bridge these kids through the worst of the malaria season that happens after the flooding, And if the mosquitoes can't establish those infections in the kids, maybe we can just keep that surge of malaria from happening.
And we saw that happen in the pilot study. We saw drastic reductions in the amount of malaria compared to the villages where we didn't do that. And what was really, I think, striking was that we also saw malaria rates in people who did not get the treatment go down. And that's probably because there were just less parasites floating around in people for mosquitoes to pick up.
So because the kids didn't have any, the mosquitoes in the villages might bite them, but they weren't picking up the parasites and then biting somebody else and transferring it. So there was a benefit even to those people who did not get the preventative treatment. And so now we got the funding from the NIH to do this on a much, much larger scale.
So we'll be in, 50 to 60 villages, probably something on the order of 35, 000 people, and some of the villages will get this chemoprevention with this long lasting medication after the next flood, and some will get the medication as well as a larvicide, which of course is something you put in the water.
to kill any developing mosquitoes to see if that does even better. So we're really excited to get that going and I'm hoping, of course we don't hope for flooding, but we're hoping that this next season will be the, when we roll it out, so probably next May.
Mary: And so we'll say, will you be also targeting just the children? Like it's like under a certain age that you will be giving the chemo prevention medicine to?
Dr. Ross Boyce: Yeah Yeah, so we go for kids, the drug is a weight based dose, and so there's a certain weight below which you can't give it, so not the youngest children, but up to about age 12 will receive it, and the reason we pick that is because, one, kids are the most impacted by malaria, so of all the deaths that happen, and there's about 400, 000 a year globally, and You About 90 to 95 percent of those happen in kids under five in Africa, actually.
And that's certainly the most impacted group, but they're also the group that tends to harbor parasites the most, and so by targeting those kids with a drug that not only prevents infection, but also clears any existing infection, We're eliminating what we call the reservoir of parasites that's sitting out there for mosquitoes to pick up if they're not already infected.
So they're really a nice it's the highest yield group. It just so happens that is also the group that suffers the most from the disease.
Mary: Yeah. And why what's the, is it the, what's, is there a theory behind why it's the kids? Is it just the immune system can't fight it that, that die, or is it just economical? What's the, are there many factors that go
Dr. Ross Boyce: Yeah, it's it's a very complex. I think immunity is one key part of it. So certainly if you or I were to get malaria not having had it before or having had it multiple times, we'd get pretty sick. But adults who live in high incidence malaria areas, get it, and they might feel tired or a little off, but they're not going to die because they've got pre existing immunity.
So it's children in these areas where there's a lot of malaria. They don't have the immunity built up and so it's those early years where they're at risk, and then there's probably some period afterwards where even before they've built up enough immunity to control it or clear it out on their own.
So it is very complex, and I think there's a lot of study that goes into it, but from the who do we target population, it makes a lot of sense to go after children just because what I talked about with the severe nature of the disease as well as them holding on to parasites more than a lot of other groups.
Mary: Yeah, no, it's no, it's very interesting too, to think that, yeah. Protecting them then can protect everyone because then there's not that the mosquito is not getting the parasites. I know that's fascinating. And how have found it in the villages? You go to is, or is it is the acceptance of you all coming in and doing this study?
Or are people happy to have you and to participate?
Dr. Ross Boyce: Yeah. We've having been at the site for 10 years and having strong local partners certainly goes a long way. This will be because of this will be the largest study we've ever done. We'll be going into some new areas where we don't have a preexisting. Relationship and trust with the communities quite as much as we do in the area where we've worked.
But for the most part we get participation rates above 90%. And to get you would never get that here in the United States.
Mary: Yeah.
Dr. Ross Boyce: It's I think you do have to be careful with it because obviously you don't want to incentivize people to do something that they wouldn't normally choose to do, but for the most part everyone is very happy both to potentially receive some benefit from these interventions, and there's also a lot of pride knowing that these little rural villages are in some ways helping really advance our knowledge of sort of state of the art science and how to prevent they really They do take a lot of pride in being a part of that.
Mary: Oh, that's wonderful. And then so the larvicide, is that something that in the community, they'll be like putting something in the pools of water or will that be something that your team would do or would answer that? Yeah.
Dr. Ross Boyce: yeah we're actually going to use something called BTI Bacillus thuriancius israelensis. I probably didn't say that but it's it's a biological larvicide, and it's been around forever. It has a long use history with things like dengue and if you were to go to Home Depot or Lowe's, you could probably find the little mosquito dunks or mosquito bricks.
It's basically same formulation as that. We are going to do some basic teaching the first time to the residents, and then we will essentially hand it to them and say, do this every two weeks. Just from a manpower perspective and thinking about treating every Area around every home and 50 or, 10, 000 homes is beyond our capability.
And ultimately, we would want folks to do this for themselves anyway. And I think it just makes sense to, to push from that perspective instead of us coming in and trying to do it all ourselves. There's nothing terribly difficult about it. You could essentially eat it. It's not terribly toxic or unsafe or anything like that.
And it really doesn't have any impact on mammals. We think that just getting it out around the immediate house area is gonna potentially be helpful.
Mary: And so what, so this is hopefully when is this potentially going to start? When's the season?
Dr. Ross Boyce: For the past three out of the last five years, there's been a severe flood in the middle to late May because we were funded in September. Yeah I don't think we're going to get out this year because it does take some amount of time to get the organization set up and get our IRBs in place, so I think our goal is next May, but of course there's no contracting with the weather, and It may rain or it may not next May, so if it doesn't, we would defer to the following year, but we're set up.
We ideally want to be ready to go next May, so that'd be May 2025. We'll be ready to intervene, but we do some baseline work first.
Mary: Yeah. It's probably a lot to coordinate something like that. It's not. Yeah. You've only had the got grant in September. It's, not that many months ago. Now, do you so do you go and yearly to Uganda? Oh
Dr. Ross Boyce: go. We actually met the strangely. She's a Texan, not a Ugandan, but we, so we alternate years. We have three children who are now eight seven and five, so we don't go for extended periods, but We do alternate years, and then we have a large team now of folks who go, we send students, Ph. students, staff members, back and forth. So it's we generally have someone there from the UNC side most of the time, and then of course we have a staff of about 20 on the Ugandan side, and we'll be getting even larger for this study.
Mary: interesting. No, I hope that be interesting to see what the results are of that. Cause it sounds like there's a lot of potential. So that's fantastic. And some new things happening. Cause I think like we said in the beginning, it is the whole, And so I wasn't wrong in feeling like malaria is not as top of news as it was, 10, 15 years ago.
I feel like there was so much talk. So hopefully things like this will bring it back to the forefront and have people, supporting the efforts of folks like you. So I guess, yeah, so I have two, two finishing questions. Number one, is there a myth about malaria that you feel like people believe that we could debunk here today?
Dr. Ross Boyce: I would actually. maybe think that the myth is that it's a tropical disease in other places. And you can look back in journals and history books about malaria along the coast of North Carolina in the early 1900s and late 1800s. It wasn't that long ago that malaria was here and throughout the Southeast.
And so I think Keeping in mind, not just the risk of it returning, we were able to eliminate it because one, we had a really good treatment, which was DDT. It was good or effective for getting rid of the mosquitoes, perhaps not great for other things. And we didn't have really high transmission because it would get cleaned out by the winters every year.
But with a changing climate and the way people are traveling, I think. Thinking that the risk is not just global, but there is a local risk as well is probably something that I think people should keep in mind and be conscious of. I don't want anyone to be scared, of course, but thinking that malaria is just something that happens over there is probably the myth, which is, An example of a great success of the past that we haven't really seen it for 40 years, but here we are.
Mary: Yeah, no, I know. I think. Yeah, because we definitely saw the news this year and that did get a lot of news. The handful of cases that were in the US with the end of last summer, I believe it was. So then I guess. So how would you, if someone's going somewhere where there is. malaria or I guess other mosquito borne disease.
For for malaria specifically, what would you recommend they do if they're going? Do they get the pills? They get, obviously, they can have the other insect protection, but what would, or what do you even do when you're going off to places where malaria can really make you sick?
Dr. Ross Boyce: Yeah, I think having an appointment, whether it be a specific travel clinic or your primary care doctor, well in advance of your trip, some of the medications that you need to take to prevent malaria need to be started well in advance of your trip. So certainly getting in To see someone, there's a really good CDC website that can tell you what you might want to talk about.
Picking a prophylactic drug, and there's different options for different situations. And certainly, Things like pregnancy, or if you're on other drugs, can impact which medication you may or may not want to take. But certainly taking something and then when it comes to the actual travel piece and when you're in the country, assuming you're in an endemic area the risk is relatively low if you're staying in an air conditioned hotel where the windows don't open.
Because most of the biting happens in the evening hours when, in theory, you're going to be inside your hotel room in the air conditioning zone. But if that's not the type of setting where you're going to be, then, there's a lot of value in repellents, and whether that be a mosquito, topical repellent that you put on your skin, or something like insect shield, or another treatment of the clothing, be it a spray, or whether it's impregnated into the clothing, that has both sort of the insecticidal and a repellent component to it.
And things like that may be increasingly important. as the mosquitoes alter their feeding behaviors such that it's not just purely in the middle of the night. And those also have the added benefit of protecting you against other mosquito borne diseases that are transmitted by other types of mosquitoes that are more common during the day.
Early evening. Not a lot of harm in being overly cautious. Certainly, as I mentioned, those of us who don't have any immunity malaria can be a real emergency if you do get it.
Mary: Great. No, I think no, that's wonderful. I do actually have one more question about, is there, is it just that mosquito is just a nighttime or has typically been like kind of Hank, like awake in the night? Or is there a reason why they, it's a nighttime and other ones are daytime. It's just different types of mosquitoes have different, times a day they like to be active.
Dr. Ross Boyce: Yeah, I can't go into the evolutionary side of things of why, but certainly, The main malaria mosquitoes, the Anopheles mosquitoes, tend to rest inside in a home or a shady area during the day, during the heat of the day. And then they tend to seek their meals in the cooler hours, ideally at night, which makes a lot of sense because the human is sleeping and in the absence of a net is vulnerable.
Other mosquitoes like those that transmit be it West Nile or Dengue or Zika tend to rest more in the outsidey shaded part of the house under a eave or something like that, but then tend to bite in the cool hours of the morning and early evening. And why they have those different behaviors, I don't exactly know, but certainly there's different risks for different types of mosquitoes at different times of the day.
And certainly having some sense of what's out there, but helps. But if you're not an entomologist, like I'm not an entomologist it doesn't hurt to be covered and protected all times of the day.
Mary: Yeah, oh absolutely. Thank you so much for sharing your information with us and we wish you the best of luck with your studies and look forward to hearing how they go and hoping, hope they can help change the world and help, reduce malaria because I know for just, decades or centuries, it's been a blight on populations and on people.
Dr. Ross Boyce: Yeah. Thank you for having me.