Haitian child Ais Cadelnaudaly, 5 year-old, is treated for malaria by a volunteer doctor at a field hospital in Port-au-Prince. AP Photo/Brennan Linsley
There has been significant progress over the past 15 years, as a result of massive mobilization to confront malaria. Around 2003, resources began flowing not only from the Global Fund to fight Aids, Tuberculosis and Malaria (GFATM), but also from the affected countries themselves, allowing for the fundamentals of success – people in place with the right tools to both treat and prevent malaria. Since 2000, the number of new malaria cases and deaths has fallen by around 40% and 60% respectively. What sounds so simple has required a fundamental shift to new tools (no long-lasting bednets, new insecticides, rapid diagnostic tests, or artemisinin-based combinations were available 15 years ago), reorganizing decaying health systems, and a focus on an “end game”.
What is an end game? In the case of malaria, the end game is at the same time obvious and enormously challenging. Obvious because the disease can be prevented (mosquito target) and treated (human target) with tools which already exist - so that it is, indeed, obvious that it can be done. Challenging because, as colleagues running national malaria programs are quick to emphasize, doing this at a national scale, given the millions of people infected, is really an uphill task. Besides the complexity of the parasite that causes malaria, the capacity of both the parasite and mosquitoes to develop resistance to widely used drugs and insecticides, the variability of the immune responses - the list goes on –, there exists an uneasy truce between the parasite and humans, developed over thousands of years. Most infections actually do not result in death, particularly in the case of adults who have some level of immunity from prior infections. If left unchecked, however, malaria has shown it can make a comeback, as it did in the 1990s, when deaths increased to about a million per year - mostly children, mostly in Africa. If merely controlled, the entire package of tools, systems and trained staff need to remain in place forever.
However, if we are ever to be released from this macabre dance with the parasite, ranging from open epidemics to quiescent infections, we do need an end game: a vision of how to free ourselves from this unending struggle. Today, this vision encompasses from elimination in one country to global eradication of the parasites causing the disease. There are three trains of thought on how this could happen.
The first hypothesis is based on a very good management of the disease with existing tools. 34 countries and territories have actually been certified as having eliminated malaria transmission within their borders, using drugs to treat it and various tools to keep the mosquito that carries the parasite from transferring it to people. Five countries have been certified malaria-free by the World Health Organization in the past decade. Sri Lanka and Costa Rica both took a focused approach with elimination in mind, and are on the path to certification. In 2014, 16 countries reported zero domestic cases, 17 reported fewer than 1.000 cases, and Argentina is now close to certification.
The second hypothesis is based on an aggressive, innovative use of existing tools – specifically, obtaining information on where the parasite is through systematic surveillance, and using available drugs on the whole population to do away with the parasite in all infected individuals, including asymptomatic carriers who do not seek treatment precisely because they do not feel sick, but who can contribute to spread the disease. With the support of different partners, surveillance, community treatment, and high levels of vector control can be brought together effectively, as shown by the promising results emerging from several highly affected countries. The feasibility of malaria elimination will be tested in Sub-Saharan countries, where the challenges are greatest. In Zambia, for example, the program is funded by the Global Fund, the US President’s Malaria Initiative (PMI), the J.C. Flowers Foundation, as well as significant national contributions; in Mozambique, elimination efforts are supported by funders such as the Global Fund, PMI, La Caixa Foundation, and the Bill and Melinda Gates Foundation. These multi-sector partnerships will be critical for the success of the malaria elimination endeavours.
The third hypothesis is based on the capacity of research to generate new tools that would make the job easier in the future, particularly in Africa, where the burden of the disease, the fragility of healthcare systems in rural areas, and the huge capacity of the mosquito to effectively transmit the disease is highest.
In fact, there is no discussion. Each of these paths to the end game is viable and active. There are countries that, given the political will, could eliminate malaria in the next 5 years. There are countries where innovative programs are being tested to accelerate progress, particularly where the mosquito is most efficient and infection rates are highest. And, finally, a variety of research efforts are being undertaken, aimed at making the whole process scalable and more effective. This includes development of new vaccines, new drugs and insecticides that overcome resistance as it emerges, entirely different approaches to the mosquito, and better use of information to bring together all that is needed.
We are not waiting for the silver bullet, but neither are we unrealistic about the challenge. What we do know is that malaria is a burden we must overcome, and that researchers working on global health must answer key questions on how to achieve this aim as quickly and effectively as possible.