Significant progress has been made towards achieving the Millennium Development Goals [1, 2], especially the target for malaria set out in Goal 6.3 of halting and reversing the incidence of malaria by 2015 [3–6]. Success has also been attained by national malaria elimination programmes, with countries such as the United Arab Emirates [7], Morocco [8] and Turkmenistan [9] certified as malaria free between 2007 and 2012. These achievements have been driven by huge increases in the availability of funding for malaria control, and the last decade has seen the increasing prominence of international donors in assisting national governments in control strategies [10, 11].

However, international donor support is at a critical juncture. The ongoing global financial crisis and austerity programmes promoted by many governments has meant the trend of increasing international funding has shown signs of significant slowdown [12]. Commitments on future funding are becoming increasingly difficult to secure, with the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund) forced to suspend new projects until 2014 with US$500 million less funding provided in 2011 than that invested in 2010 [13, 14]. Faltering funding will, inevitably, jeopardize the progress of recent years in malaria control and raise the likelihood of deteriorating morbidity and mortality trends and the threat of resurgence in transmission [15–17]. In an austere era, sustaining momentum in malaria control requires that limited financial resources are deployed with maximum efficiency, a sentiment emphasized in the most recent Global Fund “Investing for Impact” strategy [18, 19]. Moving beyond slogans to achieve this objective requires a comprehensive triangulation of (i) existing funding on malaria control from all sources in each endemic country, (ii) the relative contribution of different national and international funders and (iii) the level of funding relative to populations at risk.

Previous studies have assessed equity in malaria financing on a global scale with a focus on investments by international donors [20, 21]. Whilst informative, inferences on overall levels of equity are limited by the omission of data on national government funding. Apparent shortfalls in international assistance may be explained by investment within wealthier nations with adequate internal budgets of their own to support control programmes. Conversely, apparently generous international support to a country may still be inadequate when national governmental contributions to disease control are low. Here, explicit measures of both internal and external funding are incorporated to provide, for the first time, a comprehensive audit of combined malaria control financing. Levels of funding are compared to revised population at risk figures, calculated using the latest 2010 transmission limits for both Plasmodium falciparum[22] and Plasmodium vivax[23] produced by the Malaria Atlas Project (MAP) [24, 25]. This analysis has allowed us to compare levels of governmental support to national control programmes as well as identify those apparently neglected by international donor funding.

A review of malaria funding from international donors, non-governmental organisations (NGOs) and government budgets received by each malaria endemic country was undertaken (Additional files 1 and 2). This funding was standardized per capita-at-risk, using combined P. falciparum and P. vivax transmission limits. National funding was compared to a regional equity level. Each of these components is now described in more detail.

This analysis indicates that external funding for malaria was approximately US$2 billion in 2010 which, when combined with national government funding, led to a total of some US$2.5 billion spent that year on countering malaria globally. However, assessments have placed annual funding needs for malaria control at between four and six billion dollars [17, 43]: a stark deficit persists, therefore, between what is needed and what is provided.

The distinction between equity and adequacy is critically important. It seems clear that few countries receive adequate levels of funding but, even in the context of this global inadequacy, there are marked discrepancies when funding is compared to populations at risk. Combatting malaria must ultimately be considered as a global endeavour and the challenge to the international community is to raise overall funding levels substantially whilst seeking to address existing inequities. The inherently interconnected nature of malaria epidemiology is most clearly exemplified in elimination settings: the threat of importation or potential for vector dispersal from a neighbouring country will always represent a risk [44]. Hence, ongoing adequate and equitable funding is needed if the gains are to be sustained and progress to date not undermined.

This analysis backs up the view that the trend for increasing funding in the malaria sector is levelling off, suggesting this deficit will remain [17]. In this context, the onus lies on funders to maintain existing levels of funding and recognize that these levels must be increased if international targets in burden reduction and elimination are to be realized. Crucially, however, it can be seen that governments of malaria endemic countries across the GDP spectrum have committed smaller proportions of their own national budgets than might be expected when compared to regional neighbours. Individual country-level assessments must be performed to determine which sector is most culpable for any deficit in the context of regional patterns of funding. In some cases, increases in both internal and external funding are required. There is no evidence to suggest a significant displacement of government funding by international support [45]; indeed the global level of government funding remained relatively consistent between 2006 and 2010 despite large increases in donor assistance.

The observed inverse relationship between population at risk and per capita-at-risk funding also presents a concern (Figure 2B) [40]. This relationship implies that funding to those countries with the largest number of people at risk is not scaled sufficiently. Whilst, in theory, economies of scale may mean that protection of large populations becomes less costly per capita, there is little evidence [46] to suggest this would compensate for the funding disparities we observe. The marked decline observed in per capita funding thus likely represents a systematic under-funding in those countries with the largest populations at risk.

The funding of disease control to minimize morbidity and mortality burdens rightly dominates global funding patterns. Africa, with the most intense transmission [22], largest burden of mortality [3] and many of the world’s poorest nations [33], receives close to 70% of all disbursements. The region has also seen some of the greatest successes against malaria, as well as some of the most notable setbacks when funding has been withdrawn [15, 16]. In contrast, the CSE Asia region represents a significant proportion of the global at-risk population, but displays highly variable per capita-at-risk support that is markedly inequitable in some cases. An important aspect of these disparities is the role of P. vivax malaria which arguably receives disproportionately little donor funding for control, especially given a mounting body of evidence suggesting its clinical importance has been underestimated substantially [47–52]. When comparing such regions it must be kept in mind that the per capita-at-risk metric does not take into account the varying epidemiology that these regions represent. Doing so requires a far greater assessment of the effectiveness of different strategies in different scenarios, beyond the scope of this study. Future investigations of this kind will better enable future comparative assessments of equity across the globe.

Of the countries targeting malaria elimination, over two thirds (24 out of 35) have above-equitable levels of funding. Due to small populations at risk, consideration of absolute monies spent, as well as per capita amounts in these cases is needed. Of the 35 nations identified as pursuing malaria elimination [53], only 15 have an annual per capita funding greater than US$2. This result, combined with the total levels of funding in these countries, compares poorly to studies that have investigated the necessary amounts of investment required for elimination [54]. Many of those nations that are funding at an appropriate level to make substantial progress towards malaria elimination are either financing the operation themselves (such as Turkey or Saudi Arabia), or are part of a concerted international elimination effort (such as Solomon Islands and Vanuatu).

An interesting finding is that patterns of DAC disbursements remain strongly linked to colonial legacies, especially for Great Britain, Belgium, France and Portugal – countries which are signatories to the Paris Declaration and Accra Agenda for Action on Aid Effectiveness that foster untied aid [55]. Similarly, disbursements from USAID are primarily directed to reinforcing PMI investments. In attempting to achieve adequacy of funding on malaria control in specific countries, these have inadvertently become drivers of uneven funding on a regional and global level.

Global funding levels for malaria are in an increasingly precarious state, and we must consolidate the gains that have been facilitated by this financing over the last decade. To do so, commitments to existing programmes that have proven successful must be reaffirmed, as well as assessing whether existing patterns of funding are the most appropriate. This analysis shows that, globally, inadequate levels of funding persist, and that there are large inequalities, which vary in importance and ease of resolution, whether through increased government support or international assistance. In some cases, international funding remains tied to colonial legacies rather than disease burden. It is crucial that such imbalances are addressed in attempting to secure adequate global funding for malaria. The very large populations at risk in CSE Asia suggest that this region should become more prominent in discussions on future investment, but increased funding should not be achieved through the diversion of funds from other schemes. “Investing for impact” represents a new principle for any future funding. Targeting the most at-risk populations and tailoring disbursement of funds to a country’s needs, whilst still framing funding decisions within the context of global disease distribution, is key. Continued monitoring and spatial assessments of national financial and disease status will enable this and allow us to maximize the effectiveness of future funding.