Malaria Elimination. The printed journal includes an image merely for illustration

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1 Malaria Elimination An Executive Summary for The Lancet Series The printed journal includes an image merely for illustration More than 2 billion people live in the 32 malaria-eliminating countries. The benefits to these individuals, their countries, their neighbouring countries, and the world from continuing to shrink the malaria map is clearly large. 1

2 Introduction 150 years ago, essentially all countries had endemic malaria somewhere within their borders. Since then, half of them have eliminated malaria and half have not. Of the present malaria-endemic countries, 32 are eliminating and 67 are working to reduce and control their sometimes high burden of morbidity and mortality from this disease. The process of shrinking the malaria map continues nowadays as it has done over the past two centuries. For more on this Series see malaria-elimination This Series in The Lancet, supported by the Malaria Elimination Group (MEG) and convened by the Global Health Group at the University of California, San Francisco, seeks to collect and analyse current information about malaria elimination that is relevant to present and future malaria-eliminating countries and to the agencies and organisations that support them. The authors of the four-part Series come from a wide range of disciplines including basic science, mathematical modelling, economics, epidemiology, and health policy. They include managers and leaders of national malaria programmes. The first paper in the Series places malaria elimination in a historical context, provides detailed information about present malaria-eliminating countries, and summarises the risks and benefits of elimination. The second paper uses mathematical modelling to quantify the relative feasibility of elimination, from both an operational and technical viewpoint. The third paper investigates the operational challenges of achieving elimination and preventing subsequent reintroduction. The fourth paper presents information about the costs and benefits of elimination and the challenges of maintaining elimination and postelimination finance over a long period. Finally, the call to action draws attention to what needs to be done over the next decade to fully maintain the momentum of shrinking the malaria map. Steady progress has been made towards shrinking the malaria map, from the endemic margins inwards, over the past 150 years. 99 countries have endemic malaria: 32 are eliminating and 67 are still in control mode. The malaria-eliminating countries need ongoing financial and technical support to overcome several challenges. The Lancet Series Das P, Horton R. Malaria elimination: worthy, challenging, and just possible. Lancet 2010; published online Oct 29. DOI: /S (10) Feachem RGA, Phillips AA, Targett, GA, Snow RW. Call to action: priorities for malaria elimination. Lancet 2010; published online Oct 29. DOI: /S (10) Baird JK. Eliminating malaria all of them. Lancet 2010; published online Oct 29. DOI: /S (10) Marsh K. Research priorities for malaria elimination. Lancet 2010; published online Oct 29. DOI: /S (10) Feachem RGA, Phillips AA, Hwang J, et al. Shrinking the malaria map: progress and prospects. Lancet 2010; published online Oct 29. DOI: /S (10) Tatem AJ, Smith DL, Gething PW, Kabaria CW, Snow RW, Hay SI. Ranking of elimination feasibility between malaria-endemic countries. Lancet 2010; published online Oct 29. DOI: /S (10) Moonen B, Cohen JM, Snow RW, et al. Operational strategies to achieve and maintain malaria elimination. Lancet 2010; published online Oct 29. DOI: / S (10)61269-X. Sabot O, Cohen JM, Hsiang MS, et al. Costs and financial feasibility of malaria elimination. Lancet 2010; published online Oct 29. DOI: /S (10)

3 Shrinking the malaria map: progress and prospects A three-part strategy is now agreed upon to eventually eradicate malaria: (1) aggressive control in the highburden regions; (2) elimination from the endemic margins inwards; and (3) research and development to bring forward new interventions and technologies. Although substantial investment has been made in parts one and three of this strategy, part two has been relatively neglected by the international donor and scientific community. Despite this neglect, 32 of the 99 countries that still have endemic malaria have scaled up malaria control and are moving from controlled lowendemic malaria to elimination. The 32 malaria-eliminating countries span all geographies, sizes, and income levels. These countries share some common features: they are on the margins of the present malaria endemic zone; they have already made substantial progress towards elimination of malaria from specific islands, provinces, or geographic areas; and, typically, in the remainder of their territory, malaria has been reduced to low rates. Many of the 32 malaria-eliminating countries will probably be successful in eliminating malaria over the coming decade. For a country to decide to move from a state of controlled low-endemic malaria to elimination will always be a matter of judgment for national decision makers, and should be based on a comprehensive Spatially progressive elimination during the past century has brought tangible benefits to millions of people, and has allowed many countries to take up the elimination challenge as their neighbouring countries have completed the task. Richard G A Feachem et al. Shrinking the malaria map: progress and prospects. Definitions used in this Series Elimination A state where interventions have interrupted endemic transmission and limited onward transmission from imported infections below a threshold at which risk of re-establishment is minimised. Both capacity and commitment to sustain this status indefinitely are required. Malaria-eliminating country A country that has formally declared a national, evidence-based elimination goal, has assessed its feasibility, and has embarked on a malaria elimination strategy. A country that is strongly considering an evidence-based national elimination goal, and that has already made substantial progress in spatially progressive elimination (eg, by eliminating malaria from specific islands, provinces, or geographic areas) and in greatly reducing malaria nationwide. Controlled low-endemic malaria A state where interventions have reduced endemic malaria transmission to such low levels that it does not constitute a major public health burden, but at which transmission would continue to occur even in the absence of importation. understanding of the technical, operational, financial, and socioeconomic feasibility of the task. Countries should be discouraged from embarking on elimination Cape Verde Maldives São Tomé and Príncipe Seychelles Comoros Mauritius Reunion Vanuatu Solomon Islands Malaria-free Eliminating malaria Controlling malaria 3

4 on the basis of national ambitions that are not founded on detailed evidence. All countries contemplating elimination should undertake a comprehensive elimination feasibility assessment, as recently completed in Zanzibar, and be guided by the results. 25 of the 32 malaria-eliminating countries are solely or mainly fighting a battle against Plasmodium vivax malaria. This was also the case with almost all the successful previous eliminators. To assist with the struggle against P vivax malaria, we urgently need improved diagnostic tests, a robust point-of-care method for screening for deficiency in glucose-6-phosphate dehyrogenase, and a better drug for the radical treatment of P vivax, particularly for the elimination of the hypnozoite stage. Several concerns have been raised about malaria elimination, including that it might accelerate resistance in the parasite and vector populations, that it might drain resources from priority programmes in the high-burden countries, and that, if unsuccessful, it might lead to substantial rebound with high mortality in non-immune populations. All these matters need detailed attention. Some of these risks are shared by the alternative to elimination, which is maintaining controlled low-endemic malaria over a long period. The benefits of malaria elimination are not sufficiently understood, but include substantial positive external factors in the form of benefits to neighbouring countries (regional public goods) and worldwide (global public goods). Several overarching challenges remain to be overcome to fully support malaria-eliminating countries. The need for improved methods for surveillance and cross-border collaborations are crucial. Development of a userfriendly feasibility assessment that can be applied by all countries embarked on, or contemplating, elimination is urgently needed. Finally, we must develop new methods to ensure adequate long-term commitment and resources to achieve elimination and maintain it for decades thereafter. More than 2 billion people live in the 32 malariaeliminating countries. The benefits to these individuals, their countries, their neighbouring countries, and the world from continuing to shrink the malaria map is clearly large, even if we cannot fully quantify it or express it in terms of US dollars. Crucially, eliminating countries need to receive appropriate support and recognition for their efforts, and the historical trend since the middle of the 20th century in shrinking the malaria map must continue. 32 countries spanning all geographies, sizes, and income levels are eliminating malaria. Many of them will be successful within the next decade. Countries contemplating elimination should undertake comprehensive assessments of malaria elimination feasibility. 25 of the 32 malaria-eliminating countries are solely or mainly fighting a battle with Plasmodium vivax. New interventions and techniques are urgently needed to detect and treat this infection. Although malaria elimination has risks, the alternative of maintaining controlled low-endemic malaria for a long period also has similar risks. Several overarching challenges remain, including the need for long-term commitment to achieve and maintain elimination. Elimination feasibility by country Science Photo Library A renewed global focus on malaria elimination needs the construction of a framework to prioritise international policy for the possibilities of shrinking the world malaria map. Such a framework should not be prescriptive, but instead be informed by existing relevant data. Recent advances in mathematical modelling, the mapping of malaria transmission, and the development of databases of country-level statistics, mean that such data are available to enable evidence-based assessments of relative elimination feasibility between countries. Malaria elimination is feasible if the technical, operational, and financial challenges to permanently stop malaria s transmission can be overcome. Elimination is technically feasible if control methods can be deployed at a sufficiently high level and length of time to stop transmission and eliminate all malaria parasites circulating locally. Technical assessments frame the scale of the operational challenge, which is itself further defined in terms of the human capital, national infrastructure, and the political commitment needed by nations to reach their elimination goals. Definition of overall elimination 4

5 feasibility requires the simultaneous consideration of both the technical and operational constraints. The analysis in the second paper in this Series describes datasets and mathematical models specific to the two most widespread malaria species Plasmodium falciparum and Plasmodium vivax and assesses the relative elimination feasibility of each between malaria-endemic countries. Although the epidemiology of P falciparum is well understood and transmission maps and models are well developed, for P vivax large knowledge gaps still remain that prevent assessment of the technical feasibility of its elimination. Technically, P falciparum malaria could be eliminated in most of the world if malaria transmission could be reduced from 2007 rates by 90%, below the threshold by which malaria sustains itself in an area, and if this reduction could be maintained for years. However, many nations, relative to others, still face substantial obstacles before malaria elimination can be considered. Evidence suggests that elimination in African countries is consistently the least feasible, with much of west and central Africa needing larger reductions in P falciparum transmission rates from 2007 to achieve elimination. Most of these countries face health-care deficiencies, political instability, and high transmission, compounded by substantial cross-border population movements that bring in infections. Elimination of P falciparum malaria from the Americas is likely to be most technically and operationally feasible, with a less than 50% reduction in 2007 transmission rates sustained for years needed across the continent. Forest and forest-fringe malaria dominates in the Americas, however, and the elimination prospects for many countries depend on the feasibility of elimination in the Amazon basin. With the exception of politically volatile areas, Asian countries are more feasible than are those of sub-saharan Africa for P falciparum elimination and for the operational feasibility of P vivax elimination. The abundance of spatial data now available enables datadriven decisions to provide evidence-based, species-specific assessments of elimination feasibility for policy makers. Andrew Tatem et al. Ranking of elimination feasibility between malaria-endemic countries. P vivax malaria is most widespread and prevalent in Asia, where the need for an evidence base and transmission modelling is strongest. The decision to embark on elimination is one that each country must make for itself, guided ideally by analyses of technical, operational, and financial inform ation at a level of detail that is not easily summarised for global comparisons. The international community, however, should have an evidence-based framework in place for setting technical support and financing priorities. Such a reasoned framework demands that data are assembled on the technical and operational constraints to elimination worldwide. Our analysis represents a starting point, and it now needs more critical use and adaptation to meet the agenda of international agencies that govern priority setting for global malaria control. The development of databases and mathematical models on aspects related to malaria elimination now facilitates construction of an evidence-based framework for setting technical support and financing priorities. Each malaria-endemic country faces a unique set of obstacles to achieving elimination, but, generally, malaria elimination from countries in the Americas seems to be more feasible with use of current methods, and least feasible for most countries in sub-saharan Africa. Although global evidence-based assessments of elimination feasibility can objectively determine the merits of national malaria intervention plans, countries should undertake detailed feasibility assessments before embarking on an elimination campaign. Operational strategies to achieve and maintain malaria elimination Over the past decade, increased funding has made scale-up of malaria control possible in many parts of the world. Although in most countries coverage with preventive measures and access to effective first-line treatment still remain below targets, some countries have achieved remarkable declines in morbidity and mortality, to rates at which malaria is no longer a major public health problem. These countries now find 5

6 MARK EDWARDS/Still Pictures The most important difference between control and elimination is the concentration of activities to identify and attack foci of clinical and asymptomatic infection. Bruno Moonen et al. Operational strategies to achieve and maintain malaria elimination. The printed journal includes an image merely for illustration themselves confronted with the choice of continuing control activities indefinitely to keep malaria at very low levels, or actively pursuing elimination. This choice is complex, especially in countries with previous moderate-to-high endemicity where the risk of continued importation of infections remains high. In the absence of clear guidance, the decision to pursue malaria elimination might be made on a political basis without careful and rigorous assessment of the operational feasibility. Politicians, policy makers, and programme managers will need to possess an informed understanding of the operational requirements for a contemporary elimination strategy so that they can set realistic goals and timelines that are relevant to present malaria epidemiology and, importantly, commit the resources necessary. Guidance for achieving and maintaining elimination is based largely on recommendations derived during the Global Malaria Eradication Program an intervention that principally involved countries with low intrinsic potential for malaria transmission and limited rates of importation of new infections. Many countries considering elimination nowadays have much higher historical endemicity levels and experience a great deal of importation from neighbouring countries, emphasising the need to revisit the strategies on which the elimination programmes of the past several decades have been based. Defining the operational strategies for an elimination campaign needs understanding of how such a programme differs from one that seeks to achieve and consolidate control. There is a broad consensus about strategies required to achieve controlled low-endemic malaria, mainly universal coverage with prevention and treatment measures, but it is important to recognise that elimination cannot be achieved by doing more of the same. The most important shift for a programme moving from control to elimination involves the concentration of activities towards identification and elimination of foci of infections through surveillance with both passive and active case detection methods. Surveillance needs to be combined with an appropriate response consisting of effective treatment and directed vector control that can eliminate not only clinical cases but also asymptomatic infections. Successful drainage of these infectious pools entirely will not be sufficient because this reservoir of infections is replenished by a stream of imported malaria from outside the borders of the country. Achieving and maintaining malaria elimination will thus additionally need identification and treatment of nearly all incoming infections before they lead to risk of transmission, or, more realistically, embarking on elimination as a regional initiative to dry up importation at its source. Nationally, political leaders will need to create an enabling environment within which strategies to support elimination would operate successfully: a well functioning health system, community participation, sustainable financing, a national and regional legal framework, and political stability are all crucial. Politicians and policy makers need to understand that malaria elimination should not take a business-as-usual approach. The most notable change will involve the evolution of a surveillance system that is linked to rapid response, robust epidemiological data, and sustained vigilance over long periods. The road to elimination will not be short, and the development of new approaches and novel technologies will be necessary. Malaria and mosquitoes are constantly evolving, and they must be met with an equally resilient attack. Malaria elimination cannot be achieved by doing more and better control; instead it needs additional activities to identify and attack foci of clinical and asymptomatic infections that perpetuate transmission. Detecting and curing both clinical and asymptomatic infections needs a robust surveillance system that combines passive and active case detection methods together with radical treatment and targeted vector control. As long as a competent vector is present, countries considering elimination should aim to prevent importation of infections through proactive case detection at the border, screening of high-risk migrants, and implementation of cross-border and regional initiatives that can reduce transmission at the source of migration. Malaria elimination needs a new programmatic approach supported by political and financial commitment, ideally involving a neighbourhood of nations. 6

7 Costs and financial feasibility of malaria elimination In countries where technical and operational barriers to malaria elimination are substantial but surmountable with sufficient investment, the feasibility of achieving elimination will ultimately be driven by economics. Policy makers in these countries will mainly rely on the answers to two questions to decide whether to pursue elimination: (1) does elimination offer a better return on investment than the primary alternative; and (2) is it affordable? Although the economics of malaria programmes have been extensively examined over the past 60 years, the results do not answer these questions. The fourth paper in this Series outlines a framework to close that evidence gap and draws insights from the partial application of the framework to elimination programmes in four countries. The framework emphasises two components that are crucial to ensure economic analysis of elimination is relevant to policy. First, since elimination is often justified on the basis of more than health outcomes, analyses should incorporate the broader economic and systems benefits that elimination is suspected to generate. Most notable are threshold benefits for which tourism or foreign direct investment, it is argued, would substantially increase only once the final local malaria cases have been eliminated. Second, the costs and benefits of elimination should always be compared with its relevant alternative: continued control (or controlled low-endemic malaria). At present, implementation of this framework and the more rational decision making that it allows is prevented by a dearth of evidence for benefits. As a result, comprehensive research of all aspects of the marginal benefits of elimination is urgently needed and should be a priority for the global malaria community. In the interim, a purely financial comparison between elimination and control can be a useful guide for policy makers. This financial comparison was undertaken through case studies in five areas of four countries that have achieved or are pursuing elimination: China (Hainan and Jiangsu provinces), Mauritius, Swaziland, and Tanzania (Zanzibar). The actual or estimated costs for maintaining control and achieving and sustaining elimination were collected from each country and extrapolated over 25 and 50 years. The case studies suggested that the cumulative costs of elimination are With elimination unlikely to be warranted on its financial returns alone, full cost benefit analysis is essential to guide relevant policy decisions. Oliver Sabot et al. Costs and financial feasibility of malaria elimination. unlikely to fall below those of control in the medium term. Although yearly costs were lower than were those for control after elimination was achieved, reductions were less substantial than commonly assumed because of the need to continue interventions to prevent reintroduction of malaria and thus were outweighed in most countries by the initial spending increases needed to achieve elimination. These findings suggest that the potential for elimination to yield cost-savings and therefore pay for itself should not be a primary rationale to pursue this strategy, as has been argued in recent years. They do not, however, show that elimination is a poor investment. Elimination could generate additional benefits that must be weighed against the greater costs. Many countries will need substantial financial support from international donors to pursue elimination. However, the present structure of global malaria financing, which is designed to achieve immediate reductions in burden rather than long-term maintenance of malaria at very low rates, is poorly aligned with the needs of elimination programmes. Successful elimination will thus need a fundamental shift in the perception of malaria investment from a so-called quick win to a routine expenditure, such as that for immunisation, with corresponding changes in financing mechanisms and policies. The printed journal includes an image merely for illustration The most robust way for a country to decide whether to pursue malaria elimination is to compare the marginal costs and benefits of doing so with the alternative of continuing control. Little evidence is available to undertake this analysis. Research into the marginal and threshold economic benefits of elimination must be urgently pursued. Case studies suggest that generation of substantial cost-savings compared with control should not be a rationale for pursuit of elimination, but that elimination might still be an attractive investment through the production of additional economic benefits. Achieving and maintaining elimination will need a step change in malaria financing from the present so-called quick win approach to one of routine expenditures and benefits such as that for immunisation. MARK EDWARDS/Still Pictures 7

8 Call to action: priorities for malaria elimination Since 1945, 79 countries have successfully eliminated malaria. Today, 32 countries are eliminating malaria and many of them might reach their goal in the next decade. Malarious countries should make evidencebased decisions regarding malaria elimination and the prevention of malaria s reintroduction. Major challenges remain, including: cross-border movement of people; weak interventions for Plasmodium vivax, the dominant parasite in malaria-eliminating countries; looming insecticide and drug resistance; and limited available funding. With coordinated global action, these challenges can be overcome. Diagnosis and surveillance are key to successful elimination; innovative and highly sensitive methods are needed. Effective programme management must be prioritised. The integration of surveillance and response capacity for malaria with that needed for other vectorborne diseases, especially dengue, might be an efficient strategy. Operational research in malaria-eliminating countries will generate new and more effective guidance and must be adopted by researchers and funders. The Global Fund s prioritisation rules risk penalising malaria-eliminating countries. The Global Fund and WHO should revisit these rules and assess how best to support elimination initiatives. Donors must also find ways to support regional approaches for elimination, and technical assistance and improved guidance to With scientific ingenuity, political will, coordination, and leadership elimination from the margins inwards will continue, bringing immediate benefit to millions and hope to many more. Richard G A Feachem et al. Call to action: priorities for malaria elimination. multicountry efforts is necessary. With no guarantee of external support, countries must find ways to sustain their own elimination programmes, perhaps through innovative financing mechanisms. A thorough analysis of the costs and benefits of elimination is needed to inform national policies and decisions. There are many active and willing partners in elimination. WHO should harnesses their efforts, knowledge, and resources, to develop and regularly update strategic and practical guidance on malaria elimination. The three-part strategy for eventual malaria eradication aggressive control in the heartland, elimination from the margins inwards, and research and development must be vigorously pursued on all fronts. Shrinking the malaria map will continue to have a crucial role in this overall strategy and will help us to, one day, realise the vision of a malaria-free world. Getty Images We urge malaria-eliminating countries to undertake comprehensive feasibility assessments, make evidence-based decisions, and develop long-term strategies before embarking on a national policy of elimination. We urge WHO to harness the skills and contributions of all stakeholders in elimination to strengthen guidance for malaria-eliminating countries. We urge the Global Fund and other donors to reward, not penalise, success in countries that have achieved controlled low-endemic malaria. We urge the research community and funders to prioritise research on the epidemiology of Plasmodium vivax, and on development of new drugs and vaccines for the elimination of Plasmodium falciparum and P vivax. 8