Chinyere Opia 00:15
Welcome to Science in Africa. This is a Nature Africa podcast for African scientists and Africans interested in science. I am Chinyere Opia. Today we'll be discussing malaria and how science and technology can be incorporated into available strategies to greatly reduce the burden of endemic countries.
Malaria is a disease that is caused by a parasite transmitted through the bites of infected mosquitoes. It is a significant public health challenge, particularly in low-income countries and marginalised populations where resources and access to healthcare are limited. Joining us today to discuss this topic is Wilfred Mbacham, a Titular Professor of Public Health Biotechnology at the Fobang Institutes in Cameroon.
Prof Mbacham 01:02
I am a Titular Professor of Public Health biotechnology. I am an expert in host and pathogen genomics, and I've been practicing in Cameroon, after my studies in the United States now for close to 25/27 years. Currently founded a tertiary education institute called the Fobang Institutes for Innovations in Science and Technology and so I do that as well as conduct research, particularly on malaria.
Chinyere Opia 01:33
Can you tell us about your current research?
Prof Mbacham 01:37
We just recruited about a hundred and fifty masters students, some PhDs to do a survey, because we are conducting an evaluation of the perennial malaria chemoprevention program in Cameroon, which is a pilot to understand the processes, but also look at the impact and the economics and cost effectiveness of that procedure; and much later on, we'll be looking at the parasite clearance post infection as part of the entire evaluation on whether it's a program that is working properly or not working and then be able to advise the government.
Chinyere Opia 02:19
You have done research into malaria resistance and have made some suggestions on how to better manage the disease in Africa. Can you tell us about that research, and how it's being implemented in Cameroon and also by extension, how it can be implemented in other African countries who also have to deal with the burden of malaria.
Prof Mbacham 02:39
So essentially, my group has been looking at the clinical efficacy of drugs, but particularly why drugs are not effective. And it so turns out that there was resistance that was heavily implanted in the country and so we were able to look at certain mutations and then speak about the correlates of those mutants with regards to the response to the anti-malarial drugs. It turns out now that after so many years since 2006, when Cameron moved to the artemisinin based combination therapy, we have been able to demonstrate recently that the resistant markers to chloroquine, so the 76T is reverting to the wild type, which is a good news, and which shows that the programs have been effective, but we do not know if the situation will change. And so, we will go back to the field, most probably next year to find out exactly the extent to which the heavy use of chloroquine and its derivatives during the COVID season, what impact they might have had on that resistance marker. The WHO and others would now do a meta-analysis or systematic review of all that we have published and will be able now to give guidelines on whether the antimalarials are working and or are not working, particularly the artemisinin-based combination therapy.
Chinyere Opia 04:07
Now speaking about artemisinin-based combination therapy, why do many experts feel that it is important to use artemisinin in combination with other therapies to treat malaria?
Prof Mbacham 04:18
As of today, those artemisinin-based combination therapy are still very effective, most are above ninety-six percent of efficacy, and so it's a good thing and I think that we need to make or put on measures on how to protect these efficacies in particular. Some years ago, in 2006 and 2007, Cameron made a very interesting mistake, but it was a good mistake, in the sense that we both released artemisinin–lumefantrine and the same time artesunate - amodiaquine for the public use in resolving malaria infections. That policy was heavily criticized, but it turned out to be helpful in the sense that while the artemisinin artemether‐lumefantrine drove resistance in one direction, it was counteracted and artesunate- amodiaquine drove it in the opposite direction. So, they kind of corrected each other; and today, we have very many and huge pockets of very sensitive parasites to the currently used anti-malaria therapy. So, I think it was a good thing. It was a good mistake we made. It is paying off.
Chinyere Opia 05:30
As you mentioned in your research despite the adoption, implementation, and deployment of different control measures by government and several stakeholders, like the one you just mentioned, malaria remains highly endemic not only in Cameroon, but other African countries. What do you think are the biggest challenges we face in eradicating this disease?
Prof Mbacham 05:50
Well, I think the challenges are numerous, and essentially, you know, despite this adoption of the different interventions, there are many areas where it is not being used. Therapy is still presumptive and even when they have to do a diagnosis, the laboratory technicians are not properly trained. There is still a very rampant use and indiscriminate use of other anti-malarial drugs in the population. They're usually frequent stockouts. The different or diverse geo-ecological settings warrant that it's not a one blanket strategy that you use across an entire nation. And if you have to redeploy different strategies, then you would see that the financial resources are not always that available. Now, there are many physicians who currently don't know how to treat malaria using the anti-malarial medications and they just prescribe as they desire.
Chinyere Opia 06:49
That sounds really serious. What are some of the most effective ways to address this concern?
Prof. Mbacham 06:55
We encourage that doctors should be retrained, technicians should be retrained, there needs to be a lot of resources deployed, so that these current measures which have proven their efficacy should be those that are largely deployed on the field. Now, there are a number of lessons we have learned out of these challenges. That first, for example, there needs to be more than one line of therapy, therefore, a multiple first line therapy that would actually solve the problem of multiple resistances and clear those from a community. We need to have a lot of additional resources to be able to carry these out; and if anything, the physicians or caregivers should go into the practice of treat, track, and test, treat and track which would effectively show or demonstrate the appropriate prescriptions that should go for the anti-malarial.
Chinyere Opia 07:53
And looking at eradication options, how do you think, or do you think we can use science and technology to combat malaria in Africa?
Prof Mbacham 08:01
Yes, I think we can. If I take the clear example of what is happening in the drug world, a lot of genomics and genetics has been known about the parasite, which allows us to know exactly what new areas to address, what new areas to attack. But if you look at also understanding the genomics of insecticide resistance in the Anopheles, then you realize that they've also understood very clearly what these resistance patterns are and the whole mechanisms. And so you start to find new things that come up into the strategies for elimination. For example, for the first time, they're using combination treated nets, in which there are two ingredients that can attack two different aspects of metabolism, or mechanisms of the insects; and so would finally kill the Anopheles; or they're doing a rotation or they're doing a mosaic in the country by stratification and knowing exactly what the prevalence and incidence is, or what the resistance patterns are, you'll find that PBO nets are being given in one area, the new generation nets are being given in another area, the pyrethroid nets are still given another area. And this is because they have mapped to know the different genetic compositions of these parasites in different areas; and that's what they're now trying to attack from the very base.
Chinyere Opia 09:16
Now during COVID, new technology was adopted in the development of a vaccine, how can these strategies be replicated in the fight against malaria?
Prof Mbacham 09:26
With the advent of COVID, and with the new technology that resulted in the production of a COVID vaccine. By taking that also and that strategy to the malaria world, we hear there are new, interesting molecules, or vaccine strategies that may soon be tested, like the R21 of Oxford University, that may also show promise. Now we've also seen that if you combine both chemo prevention and vaccinal prevention, you bring down the incidence of malaria dramatically, as was demonstrated in Burkina Faso and Mali. I know that also, there is something called the Gene Drive, in which you can genetically modify mosquitoes and by reason of these genetic modifications, they eliminate themselves. I think the moratorium that others are playing or putting up is that we do not know if we completely eliminate the anopheles, what else could creep up or what other competence could other vectors have in the transmission of malaria? And so, we're looking at this with a very close eye and a keen sense of how you deploy genetic material into a population or into a community.
Chinyere Opia 10:34
So, you talked about WHO's recommendation of combining pyrethroids. Most recently in March 2023, they published a guideline for malaria, which covered two classes of dual ingredient ITNs. They have different modes of actions, like it said in the recommendation, and they believe that if they include these two active ingredients in an insecticide treated net, the likelihood of mosquitoes being resistant to both will be greatly reduced. Although you mentioned it briefly, what is your take on this recent development?
Prof Mbacham 11:05
Well, I think it's a good development in the right direction. Why? Because by combining pyrethroids with chlorfenapyr, that chlorfenapyr is a parallel insecticide that would enhance the killing effect on the nets. The other combination is pyrethroid with pyriproxyfen, this pyriproxyfen is an insect growth regulator, and this insect growth regulator will disrupt the mosquito growth and reproduction. And you can tell already by this combination, that most of the parasites that bother us these days would not have a vector through which it will be transmitted from man to man. And therefore, I think it's a wonderful, most welcome recommendation, because we've been asking for quite a few decades now, why there aren't combination approaches in vector control. And I think this is what we're now getting as one of the best answers because there's now evidence that both would work and bring down the mosquito population.
Chinyere Opia 12:02
And your research focused on the treatment of malaria. But it showed that, that there have been many setbacks with resistance to many treatment options. But what have you found to be the most effective strategies for preventing and treating malaria in African countries? And how can they be scaled up to reach more people, especially people with lower socio-economic opportunities, or status because from research, most people from lower socio-economic status, are more prone to the disease, malaria?
Prof Mbacham 12:30
Well, I think the first thing to do is to come up with a very good strategy, both for its prevention but also to make the medications available. Now in Cameroon, there's something called a drug revolving fund that is being practiced in some regions. And essentially, there is always medication available, which you can purchase and resell at very low cost and then let that fund replenish the stocks because one of the things that the rural population suffer from is stock outs. Now, these stockouts would make that if the next time that they have malaria, and there are no medications, then they would obviously rush to the herbal medications or other forms of medications to get treatment. Now, the president of Cameroon did one wonderful thing, which was an ease to treatment of children under five for free, because it's one of the most vulnerable of the populations. I think that that policy is helping in exactly curbing malaria in that vulnerable group. The other group that we would love the president to also give free medications would be pregnant women who would adversely suffer from this.
Chinyere Opia 13:44
That’s really interesting. I didn’t know that. But what is the role of the ordinary man in all these strategies to mitigate or eradicate malaria?
Prof Mbacham 13:53
I would propose we keep on educating the population. Now because people don't really care for their health when they are well. I think that a lot of education should be done during our hospital visits, and during maybe church attendances and in churches, so that even before the pastor comes up to talk, you can effectively dish out the public health message. One last aspect which is important and which has not been given a lot of attention to is that of taking care of the environment. The environment is where the mosquitoes breed and there isn't very much of a promotion of environmental care.
Chinyere Opia 14:28
Now, you brought up an important topic, which is doing the right things first before putting other things in place to achieve a set result. In your research, you mentioned that the principal drug recommended to curb resistance is artemisinin-based combinations. But as you also mentioned, some of these drugs developed in Asia were introduced into the African market without a broad-based efficacy testing in different ecological sites. Countries like Cameroon adopted one type of artemisinin-based combination over another without a national evidence guiding its choice. As a researcher, what are the ethical considerations involved in malaria research and intervention in Africa? And how do you suggest we ensure that these efforts are conducted in a responsible and equitable manner so as to achieve the best or set results that we are looking forward to?
Prof Mbacham 15:18
Well, you know, sometimes it is not always necessary to do an efficacy test to find out if a drug is effective or not. Places with similar ecological profiles, can also serve as the evidence for other countries. So I think this is what most countries including Cameroon looked at, at the time that they were bringing in the antimalarials, the new artemisinin based combination therapy but did urge and with the support of groups like the WHO itself, but also the President's Malaria Initiative, groups like UNITE, groups like the DFID, groups like the Wellcome Trust, groups like the NIH, they have been sponsoring different forms of research to actually encourage the evidence that resulted in the use of these. So if there's evidence already that in a another setting of similar geographical or ecological profile, it's working, then we have an added ethical responsibility first to save the lives this is the strategy that Africa used to ethically save lives before going on to do the researches and prove that in every particular setting, they may have, this efficacy is still the case.
Chinyere Opia 16:29
So, you've briefly talked about it, but how can we measure the impact of malaria interventions in Africa? And from your research, or your experience, what are the most promising approaches for monitoring and evaluating progress?
Prof Mbacham 16:43
Well, I think it's first continuous monitoring. You must have understood also the WHO strategy of test, treat, and track. The track would mean that there's continuous surveillance, to see exactly where there are pockets of resistances. So basically, it's that kind of in-depth and detailed analysis of regions of districts and of health areas that would bring the necessary information, both for insecticide resistance, but also for the anti-malaria resistance. And I think this evidence needs to be generated for the Ministry of Health in different countries by the researchers and this is what they're called upon to do. The information that is out there should not only be left in the journals, they should be taken out and translated into meaningful gains.
Chinyere Opia 17:24
As someone who's been researching malaria for a long time, how has the scientific understanding of malaria evolved over time? And what are some of the most promising new strategies for preventing and treating the disease that you have also discovered in the course of your research?
Prof Mbacham 17:42
The microbiome is so important nowadays and everybody's rushing to it to be able to make and understand exactly how that is contributing to our protection and our immunity against infections and other non-communicable diseases. Besides the understanding of genomics, it's new technology that has come. Everybody's rushing to it, everybody's beginning to have a clue on exactly what this is. We're even able to detect parasites that could not be seen under the microscope, and that's because of new technology, this new technology has brought about new types of engineering principles, and new types of molecules are coming up. There is a new vaccine that is out of these kinds of new technology that Oxford University is developing. And that's the R21, there's a lot of hope. But there is also a lot of investment that needs to be done for the African continent to gain benefits. And what that means basically, is that capacity still needs to be built on the African continent, because it is not by the North, doing a lot of the research and dictating it to us. People who live with the disease understand it better, and if they have the technology, they will drive the research in a totally different direction and even with low costs, we'll make a very high impact. I'm an advocate for this kind of approach.
Chinyere Opia 18:54So, you've talked about the role of genetics and susceptibility to malaria. So how do you think this knowledge can be used to develop more effective treatment and preventive measures?
Prof Mbacham 19:05Well, I think by reason of studying the genetics, we'll get to identify new targets, we get to identify new ways of making new molecules. And using the human cells or the cell as a factory for this manufacture, we're going to see new types of synthesis. We're going to adopt new engineering principles, like those of saying that normally all biological materials may not only be known for their biological materials, but they may have some other intrinsic or abstract properties that we can also exploit. We would also learn to decouple the processes and let people specialize in different areas. And so the value chain for production of new molecules would almost be so highly specialized, that with each person doing a highly specialized element when you put together the entire chain, I think Africa stands to benefit. Now, we need to have a lot of schools that teach this don't teach the old type of science, the old types of science is past. And I think that the new biology and all of what it carries with it is something that we can gather from. Artificial intelligence and machine learning has seen the light of day we need to appropriate these new technologies. Let them also enter the cell, let them also go into how we generate material, bio-computations. These are new sciences that need to be promoted, that need to be encouraged. There would be an initial phase of sluggishness in adopting this new science but once the momentum, once it has been understood that this is the way to go; I think that very rapidly, you will see a lot of scientists come out with very innovative things that would help in bringing down this, this scourge that has bothered us for such a long time.
Chinyere Opia 20:45Thank you, Prof Mbacham. Exciting advancements, such as the development of new vaccines and improved diagnostic tools, provide hope for the future. It's critical that we continue to work together to address the challenge of malaria.
Thank you for joining us on this episode of the Science in Africa podcast. If you are interested in finding out more on the important work being done by African research scientists, check out our Nature Africa website at nature.com/natafrica; and until next time, I am Chinyere Opia.
