April 24, 2009
Q&A: World Malaria Day
April 25 is World Malaria Day. It was established as an opportunity to recognize the global effort to provide effective control of malaria. Tim Parsons, director of Public Affairs for the Johns Hopkins Bloomberg School of Public Health, discussed the broad array of research and programs to alleviate the malaria epidemic with Peter Agre, MD, professor and director of Johns Hopkins Malaria Research Institute, and Matthew Lynch, PhD, program director of the Global Program on Malaria at the Johns Hopkins Center for Communication Programs and vice chair of the Roll Back Malaria Partnership Board.
Tim Parsons: Malaria is a tremendous health burden throughout the developing world, particularly in Africa. Where are we today in the global efforts to conquer this disease?
Peter Agre: I think that from a basic science standpoint malaria is becoming better understood and we hope this will lead to the development of new therapies, diagnostics and preventive measures. We’re not done with our task. The advances in the past decades are often met with reversals. Medications are becoming less useful due to drug resistance, so we are on something of a treadmill, hoping to make progress. It’s still a big challenge. If you look clinically at the disease burden, the number of people affected, we are probably losing ground. There are still a billion people on this planet living on less than a dollar a day and a lot of those people have malaria.
Matthew Lynch: I would agree, but I think there is hope that things are moving along. We have seen a lot of progress recently on a number of different fronts, but we are still in a situation where as best we can tell a million people a year die of malaria. The vast majority of those, probably 90 percent, are young children in Africa. The burden of mortality is mainly in Africa, but there is a significant burden of morbidity, of sickness throughout the world—in Latin America, South America, Southeast Asia, South Asia—that also takes quite a toll in productivity and health services. I think there are reasons for optimism. Advances are being made in understanding how malaria works. There is a lot of progress on diagnostics, which I think has tremendous potential to reduce not only the burden of malaria but also the largely unreported burden of misdiagnosis of malaria, particularly in Africa. Children with fever are being treated presumptively for malaria and often they go home to die of pneumonia. I think there is a potential here to reduce a large disease burden through addressing malaria.
TP: What do you think is most needed in the fight against malaria?
PA: I think we need young scientists to engage in malaria research. The number of young Americans going into science continues to decline. We are getting the young people from other countries. They come here to work in science and we are really grateful that they will come here, but they can choose cancer biology, neuroscience and many different areas of research. I think we need to keep malaria in front of them. This is where I hope to make some contribution, by raising the profile of malaria research. It’s not over. It may not be glamorous in terms of some of the trendy things in science, but for human importance, it has got to be at the top of the scale.
I think good things are happening.
ML: I absolutely agree. I think it is critical more people come into malaria work. We have a desperate need for good managers at the district level across Africa. We need more MPH programs in African universities to train people, distribute medication and make sure that care exists in poor households.
TP: The Bloomberg School of Public Health has many faculty and programs working on malaria, often looking at different aspects of the same problem. Could you tell me about some of the projects you and your colleagues are working on?
ML: We [at the Center for Communication Programs] work largely on behavior change communication. We are working on treatment-seeking behaviors so that when children become ill with a fever in Africa, mothers and caretakers know that they need to get these kids to a qualified health care provider as quickly as possible. One of the problems with malaria is that it can kill within 24 to 48 hours. That is really fast for people living in isolated rural households who may have to go to a lot of effort to get their kids to a care facility.
Insecticide-treated nets are a very effective measure for preventing malaria, but making sure that households have access to them, understand how to use them and realize the importance of using them requires a fair amount of discussion. It is not something that is self-evident to everyone, and so it is not just a matter of getting the nets to the village. It also means making sure that people in the village understand the relevance of the nets to their needs in their households.
On a larger level, there is a need for coordination between donors and implementers. I work on the partnership board of the Roll Back Malaria Partnership, and we’re making good progress in terms of being able to identify priority interventions that we are all going to support. These interventions are based on good evidence so that we have a lot of continuity between donors and what is actually going on in countries. We have done a lot of work to strengthen national control programs so that they are based on good evidence.
I want to reinforce something that Peter mentioned a little while back, that we have to make sure that we don’t declare victory too early. We now have, for example in Zanzibar, a cohort of 4-year-olds who have never had malaria, so they have no immunity to malaria. Now, this is a wonderful success. Zanzibar has dropped malaria prevalence down to something like 1 to 2 percent and that’s a tremendous achievement, but those kids have no natural immunity. If we stop distributing the nets, if we stop pushing for use of the nets, if we don’t ensure that the treatment is readily available, and then we have an epidemic come back through, the carnage would be terrible. We have to keep pushing.
PA: I think our efforts should be viewed as complimentary to those that Matt has already described. Our efforts are often very basic. In rural Zambia we have a field station affiliated with a mission hospital in Macha, where malaria has been of great prevalence over the previous decades. There is suggestion that it is on the decline there. The explanation is beyond us, though. Are people really not experiencing malaria any longer? Some of the research efforts at the Macha site suggest that there are a large number of people in the area who don’t believe they have malaria. Their peripheral blood analyses show no malaria but they have subclinical forms of falciparum malaria. This is not well understood biologically. We don’t know where the malaria is hiding. Is there a way we could actually confirm this unambiguously? I think that it is of great importance to know if it is really gone, as opposed to in hiding. It is a fundamentally important issue in terms of how public health will respond.
Here at Johns Hopkins in the laboratories we have many efforts looking at the development of novel vaccines. Two of our investigators are working on different approaches with the idea that we will have vaccines that block transmission of malaria by preventing the organism from growing in insects or in people. We don’t guarantee that either will be 100 percent successful but I think that we need to pursue these approaches and to understand the basic science of the vaccine, which of course requires advances in the understanding of human immunology. We have investigators looking at human immunology of the vaccine response. We have structural biologists looking at high-resolution structures of key molecules synthesized by the parasite, which might be potential drug targets. We also have investigators looking at the development of new drugs or modifications drugs. Drug resistance is a known hazard and as Matthew said, if the organism comes back and resistance is gone, there is no native immunity, and we have the setting for a catastrophe.
Some ideas in basic science will not lead to practical advances, but I think we have to have a broad portfolio in order to feel like we are doing the basic studies that may have practical applications.
TP: You both mentioned being optimistic and hopeful about the future. Where do you see the malaria problem in the decade to come? And what are some of the signs that make you hopeful?
ML: We now have a global malaria action plan, which is, for the first time, a consensus roadmap of where we want to go. The steps to get there focus first on scaling up our impact in Africa. We are trying to get more insecticide-treated nets and wider access to effective treatments across entire countries and into as many households as we can so that we can relieve the mortality and transmission in Africa. We are on track for good success. There are obviously conflicts in Africa that are a huge challenge to achieving our goals, but I think we are on track. We are seeing tremendous success in Rwanda, Ethiopia and Zambia with declining prevalence and transmission of malaria.
I think the challenge over the next 10 to 15 years will shift. As we start to dampen down the pressure of mortality and stop the carnage in Africa, we are going to need better advocacy in order to actually target elimination. The natural conclusion is to actually get malaria under control to the point that we don’t have to pump in billions of dollar every year to maintain control.
PA: I am extremely heartened by the increasing visibility of the malaria problem and the incredibly valuable contributions from philanthropists. There is a recent announcement by our National Institute of Health for international centers for excellence for malaria research. This new emphasis on the problem gives me confidence that the efforts are not going in vain—that the difficulty, severity and importance of the problem are being recognized by those who can make a difference. In terms of development, as a basic scientist, you have got to be optimistic. There is enough reason to be discouraged. If you don’t have a basic level of optimism then you’ll probably never come to the lab. Hopkins research scientists have been able to modify artemisinin [the current treatment for malaria] to increase its effective dose tenfold. This is a simple chemical approach to improving a medicine that might be of declining potency. I find that exciting. We have basic scientists here working on insect biology. Insect biology—vector biology—is not something that is usually present at a medical school or a school of public health, but it is here. By looking at very creative approaches we were able to engineer insects that are actually resistant to passing malaria. You might think, why don’t insects normally do that? We don’t know the answer, but it might be a way of interceding in the populations. It is theoretical and not yet practical, but all great breakthroughs in science start as advances that aren’t obvious in terms of their potential. The potential becomes determined as we look further.
TP: Before we conclude, you wanted to talk about some of the work done by your colleague William Brieger, who is a professor in the Bloomberg School’s Department of International Health and senior education specialist with Jhpiego.
ML: Well, since Bill isn’t here I wanted to talk little bit about the work he and his colleagues at Jhpiego are doing. They have a particular area of capacity in dealing with malaria and pregnancy. Malaria in pregnancy is a huge problem. It is one of the leading contributors to low birth-weight babies in malaria areas. We know that low birth-weight babies are at a significantly higher risk of death in the first few hours of life. By encouraging women to come into antenatal services earlier, we can give them insecticide-treated bed nets, which will protect them from the mosquito bites and acquiring new cases of malaria. It’s a win-win situation offering free bed nets for the first antenatal visit. You increase women’s willingness to attend antenatal services, where they also get screened for syphilis and receive tetanus shots, iron supplementation, and all of the other benefits that come with antenatal services. They also get the protection from malaria and there is a great benefit to the child when it is born.
Focusing resources on malaria can often be interpreted by other disease advocates as reducing the slice of the pie that will go for the child’s survival, HIV, tuberculosis or any of the other huge health needs in the developing world, but I think that one of the key points to keep in mind is that when we address malaria across the spectrum, we actually strengthen the health system.
TP: Anything else either of you would like to add?
PA: I just want to underscore that until malaria is brought under control, these parts of the world will never flourish. The people are sick because they are poor. They are poor because they are sick, and when a child is sick or dies the loss is immense. While the indicators suggest that the prevalence of clinical malaria is declining, it is still a huge problem. If we are reducing by thousands the number of deaths, we should be optimistic. On the other hand, our work is not done. To put this in a little perspective, the United States had malaria and it was not eradicated here until World War II. In the poor regions of the South it was a big problem, but we were able to eradicate it. The challenge is still larger in places like Africa, Southeast Asia, South Asia and Latin America, but these are things that we can address, and I think that in terms of the social dysfunction that comes from having this scourge, that this is an important undertaking.