Dr. Silas Majambere is a medical entomologist who took up the position od senior scientist with the Innovative Vector Control Consortium recently. MalariaWorld asked Silas about his past work and future ambitions in the field of malaria elimination.
You have been working directly in the field of operational malaria control in The Gambia using larval control. What is your current opinion on the role of larval control? Is it indeed a matter of ‘few, fixed, and findable’ sites or is there a wider role for larval control?
I have spent four years in The Gambia investigating the role of larviciding for malaria control. The program covered 400 km2 of floodplains with ground teams of spraymen applying Bacillus thuringiensis Israelensis (Bti) weekly to all water bodies we had previously mapped. This was indeed hard work at +40 degrees Celsius, and I commend the team that took the task. Unfortunately we only had a small impact on adult mosquito density and were not able to show a reduction in malaria prevalence following the larviciding program.
There were two main reasons we were not able to show impact: (1) the extent of the floodplains is simply too large to spray by ground teams, unless bigger teams are deployed; (2) Gambia river is highly tidal and Bti is likely to have been washed away after application.
Larval source management (LSM) has a role in malaria control, and it is not just my opinion, but it is historically proven (Brazil, Israel, USA, etc.). Although I understand the caution around “few, fixed and findable”, those terms are very relative and should not distract us.
Many African countries have adopted LSM for malaria control, and it is one of the tools in their Strategic Plans. While the scientific community is debating, the train has moved, and we’d better catch up and support the countries adopt best practices for LSM, including robust monitoring and evaluation, and use of WHOPES recommended products. With the technology we have today, I believe we can design better LSM programs than 80 years ago in Brazil.
You were also involved in malaria control on Zanzibar (United Republic of Tanzania). Malaria is ‘almost’ gone there. What, in your opinion, is the best way to turn Zanzibar into a malaria-free island?
Malaria prevalence in Zanzibar has decreased dramatically over the past decade mainly due to improvement in case management with artemisinin combination therapies (ACTs), improved diagnosis with rapid diagnostic tests (RDTs) and high coverage with vector control interventions, mainly long lasting insecticide treated nets (LLINs) and indoor residual spraying (IRS). These interventions achieved an unprecedented reduction of malaria prevalence in Zanzibar from 40% in 2005 to between 0.2 and 0.5% in 2011. Unfortunately, we have been stuck there for the past five years and in my opinion we are not likely to make further progress with current tools and approaches only.
I believe there is an opportunity here to be bold and introduce a “disruptive” way of thinking. Although some are proposing mass drug administration (MDA) with gametocidal drugs, and the 3Ts (test, treat, track), I believe there is an opportunity to be bolder and go after the vector. One main victory we are not celebrating is that we have nearly eliminated the notorious Anopheles gambiae ss from many parts of East Africa and elsewhere, and there is a real prospect of eliminating the main malaria vectors in many settings in Africa. Zanzibar being an island could be used as a show-case for malaria vectors elimination, but I am convinced this is not just a solution for small islands. Again many successful malaria programs relied heavily on destroying the vectors, I don’t see why it should not be considered in Africa.
A world almost free of malaria in 2030. Myth or reality? What is your opinion?
Setting targets is helpful in keeping us focused, and there is often that magic of a deadline that pushes people to work harder than they imagined they could. But of course there is always a danger of not meeting the deadline and exposing yourself to harsh judgment for having set unrealistic goals.
I believe a number of countries that are malarious today can become malaria-free in 15 years if considerable efforts are made to improve access to treatment and prevention, if that vaccine we’ve been waiting for eventually arrives, and if new strategies are adopted mainly for vector control. There are many “Ifs” here, but I’m convinced we will not achieve the goal of elimination if we continue business as usual.
One important point to note is that as much as we shy away from boldly facing it, malaria is a disease of poverty. If you are well fed, live in a decent house, and have access to health care, you are less likely to get malaria, and even when you do, you are less likely to die from it. It’s high time we addressed the root causes of the problem.
Congratulations: You are about to start a new job with the IVCC. What will your role be within IVCC?
Thank you. I have just started my new job at IVCC as Senior Scientist. IVCC is a product development partnership (PDP) in vector control. Their main role in partnership with industry and academia is to develop new insecticides for public health. For the past 30 years, no new public health insecticide has been developed. I am privileged to join IVCC at a very exciting time when IVCC in partnership with industry are about to bring three new public health insecticides to market. IVCC is also working to address the problem of outdoor and residual malaria transmission (the transmission that is not prevented by insecticide treated nets and indoor residual spraying). My role is mainly to work with academia and manufacturers, to develop new vector control products that can address the problem of outdoor/residual malaria transmission.
During the recent ECTMIH conference you were pretty outspoken about the role of African scientists solving the African malaria problem. Can you elaborate a bit more on this here?
In malaria like in many other areas, Africans are often implementers of decisions they have not participated in making. This might sound political and is certainly a generalization that does not apply everywhere. Without assigning blames, it is important to realize that today we are reaching a critical mass of young African malariologists who can take the lead in shaping the malaria elimination agenda. They are young, well trained, motivated and enthusiastic about the role they can play in alleviating the problems plaguing their continent. It is equally important to recognize that we reached this stage with the help and dedication of non-Africans who spent their time and money to fight the burden caused by this preventable and curable disease.
Local problems often have local solutions, and African Scientists and implementers will play a great role in leading the way to malaria elimination. They need to own the agenda and any sustainable initiative should aim to equip them to do so. The funding community needs to realize that, the scientific community needs to adjust to that, but more importantly the African community need to demand that.
Silas nominated the next person for an E-interview. This person will be contacted soon.