In a recently published article in the New England Journal of Medicine, the team led by Dr. Mayor shows that a decrease in malaria transmission can have adverse clinical effects on pregnant women that get infected, and underlines the importance of sustaining efforts in its elimination. In this interview, Dr. Mayor tells us, among other things, why he decided to do research and discusses the key challenges to malaria elimination.
Why did you decide to become a scientist?
During my training as a biologist, I was attracted by everything that had to do with research, with discovering and dealing with new things. I think that ever since I was a small child I've had curiosity to understand why things happen. I suppose it is that curiosity that led me to choose research.
In your everyday work, what motivates you the most?
Again, the idea of confronting questions that are not solved yet, and the possibility of providing an answer. I think that is what motivates me the most. It is a very creative job and that creativity results highly stimulating.
And what frustrates you the most?
Sometimes obtaining funding is not easy. I suppose it is like with all scientists, we have to send five proposals to have one that is finally approved. That is maybe one of the most frustrating aspects – that initial rejection when you submit a proposal. However, if dealt with correctly, that frustration can actually lead to the improvement of your ideas.
In a few phrases, can you resume the conclusions of your last publication in the New England Journal of Medicine on the impact of malaria reduction on pregnant women?
Basically what we have observed is an important decrease in malaria over the last 10 years in the endemic area of Southern Mozambique. That reduction has led to a decrease in naturally acquired malaria immunity, an increase in the parasite density in infected pregnant women and a worse clinical outcome of these infections both in the mother (in terms of anemia) and the newborn (in terms of low birthweight).
As a result of this study, we are stressing the concept that pregnant women represent an ideal sentinel group to monitor malaria levels in those endemic areas that are trying to eliminate the disease.
This is precisely one of the priority research areas in the field of malaria elimination: identifying methods that can be applied in the field to measure how much malaria remains in the area. The follow-up of pregnant women could be a good option since they are relatively accessible thanks to the routine antenatal consultations.
We are currently working to validate this strategy.
Does the elimination of any parasitic disease involve this "dangerous" phase?
I think it is the case for any pathogen that can be controlled by naturally acquired immunity. A decrease in the exposure leads to a decrease in the immunity and therefore a reduced capacity to defend yourself against the parasite.
The key issue here is to be as quick as possible. Once the elimination process is launched, you have to put all efforts into ensuring that the reduction in transmission will be quick and effective. Another important lesson of our study is that the efforts need to be maintained. We should not relax once the transmission has decreased. We have to continue.
What do you consider to be the main contribution to the malaria field in the last decade?
I think it is the paradigm shift from control to elimination. Ten years ago the concept of elimination was not even on the international agenda. All efforts focused on reducing the negative impact of infections through preventive and control measures. However, the new emphasis on elimination has not only opened up new scientific questions but has also triggered the will and engagement to achieve it. For me, this has been one of the most relevant changes.
And the biggest challenge?
The challenge, again in the context of elimination, is avoiding the reintroduction of malaria. Several initiatives are currently underway to eliminate malaria. La Caixa Foundation and the Bill&Melinda Gates Foundation are joining forces with the Manhiça Health Research Center (CISM) and ISGlobal in order to coordinate the efforts aimed at eliminating malaria in Southern Mozambique. It can be achieved but, for me, the main challenge is sustaining the efforts to avoid the reappearance of the disease. This implies monitoring residual malaria, identifying possible outbreaks and avoiding its reintroduction by travelers or mobile populations.
This is one of the major challenges and implies maintaining long-term efforts. As it already happened in the 50s when there was a first attempt to eliminate malaria, if the efforts decrease, the disease comes back. And this is precisely the point we want to make in our paper published in the New England Journal of Medicine.
What do you think of the Global Strategy for Malaria 2016-2030 published by the WHO?
I think it is very ambitious but reasonable. It is a good proposal, with specific targets that will require a great amount of effort. But I believe that it is one way of setting goals in the short to medium term. As I said, it is an ambitious but stimulating agenda for the scientific community. What I think has become quite clear is that we can no longer accept to live with malaria. The moment has come to join efforts to eliminate it once and for all.
Malaria Elimination Initiative