Marcel Tanner; Don de Savigny1
Swiss Tropical Institute, Socinstrasse 57, 4002 Basel, Switzerland
After a lapse of almost 40 years, malaria eradication is back on the global health agenda. Inspired by the Gates Malaria Forum in October 2007,1,2 key organizations are starting to debate the pros and cons of redefining eradication as an explicit goal of malaria control efforts. Attempts to eliminate malaria in southern Africa3 and Pacific Island states,4 and WHOs Global Malaria Programme agenda and field manual for malaria elimination,5,6 foreshadow this movement towards another global attempt at eradication.
When marking 60 years of WHOs commitment to fighting malaria, we must ask what has been achieved, but also what can we learn from the past. We now know so much more about the biology of parasite-host responses, the determinants of endemicity and transmission dynamics, the social, economic and cultural implications of malaria at household, community and national levels, and the demands made upon health systems in endemic countries. We do not yet know how to synthesize and integrate this knowledge to achieve elimination in different settings.
Regional malaria elimination campaigns were first conducted in the late 1940s, preparing the ground for the Global Malaria Eradication Program in 1955. This campaign succeeded in eliminating malaria from Europe, North America, the Caribbean and parts of Asia and South-Central America.7 But no major success occurred in sub-Saharan Africa, which accounts for 80% of todays burden of malaria.8 When the aspiration of global eradication was abandoned in 1969, the main reasons for failure were technical challenges of executing the strategy especially in Africa.
The post-eradication era from 1969 to 1991 focused on technical issues, and research and development for new tools, leading to advances in drug and vaccine development, vector control and insecticide-treated nets. These decades also brought a better understanding of the social, economic and cultural dimensions of malaria. There was little global support provided specifically for malaria control in the newly independent states of Africa that were struggling to establish broad-based health systems and primary health care. By 1992, the combination of a worsening malaria situation and promising technical developments led to renewed global focus on malaria control.
The Roll Back Malaria initiative, launched by WHO in 1998, led to the Abuja Declaration in 2000, which defined progressive intervention coverage targets for control designed to eliminate malaria as a public health problem, while emphasizing that this could only be achieved through vastly strengthened local health systems.9 Increased resources through the Global Fund to Fight AIDS, Tuberculosis and Malaria, the World Banks Booster Program, the US Presidents Malaria Initiative and many others has meant that this page is finally beginning to turn as intervention coverage is rising.10
It is against this background that we hear this call for elimination/eradication. The challenges remain formidable. We all know that elimination in Africa is not possible with current tools. But efforts must focus beyond simply developing better tools, to include how existing and future tools can be strategically combined for maximum synergistic effectiveness when integrated into different health and social systems prevailing in endemic areas. Aiming at elimination and eradication further implies the need for effective surveillance strategies to monitor progress (again a challenge for health systems). This in turn requires a better understanding of malaria transmission heterogeneity in a globalized world with rapidly changing dynamics in environment, climate, migration and transnational cooperation.
Maintaining long-term momentum in the face of success in regional elimination while waiting to achieve final eradication will be a major challenge. Shrinking the map by starting on the malaria margins with the "easy-to-eliminate" settings will boost morale initially but may bring marginal benefits to such areas at the expense of those where the burden of malaria is highest. Any strategic plan and here we learn again from the past needs to be a synchronous global effort, locally adapted in all endemic areas.
Although we lack sufficient knowledge, systems and tools to eradicate malaria today, we do have a window of political will and financial resources to refocus on the goal of effective control through universal coverage of appropriate interventions. The prerequisites for a successful start are: (i) a process of inclusive discourse to agree on global vision, goals and strategy; and (ii) a global plan for all endemic areas describing how, where and when we move from control towards elimination. What must distinguish the new era, especially in Africa, is a real rather than rhetorical emphasis on health systems.
1. Bill and Melinda Gates Foundation Malaria Forum Day 2, 17 October 2007 [Transcript] .
2. Roberts L, Enserink M. Did they really say...eradication? Science 2007;318:1544-1545. Available from: http://www.sciencemag.org/cgi/content/ full/318/5856/1544.
3. Strategic plan to fight against malaria in the region. Southern African Development Community Ministers of Health; 2007.
4. Commitment to malaria control in Solomon Islands and Vanuatu. Australian Government Overseas Aid Program; 2007.
5. Delacollette C, Rietveld A. WHO GMP-informal consultation on malaria elimination: setting up the WHO agenda. Tunis: WHO; 2006.
6. Malaria elimination: a field manual for low and moderate endemic countries. Geneva: WHO; 2007.
7. Carter R, Mendis KN. Evolutionary and historical aspects of the burden of malaria. Clin Microbiol Rev 2002;15:564-94. PMID:12364370 doi:10.1128/CMR.15.4.564-594.2002
8. Lopez AD, Mathers CD, Ezzati M, Murray ChJL. Global and regional burden of disease and risk factors, 2001: systematic analysis of population health data. Lancet 2006;367:1747-57. PMID:16731270 doi:10.1016/S0140-6736(06)68770-9
9. The Abuja declaration and the plan of action. Extract of: African Summit on Roll Back Malaria, 25 April 2000, Abuja. WHO; 2007 (WHO/CDS/RBM/2000.17).
10. Malaria & children: progress in intervention coverage. New York and Geneva: UNICEF and Roll Back Malaria; 2007.