Discussion
Investments in malaria control and elimination activities were estimated at around $2.9 billion in 2015.1 To accelerate transmission reductions and consequently further reduce malaria-associated morbidity and mortality, we estimate that global annual investments in malaria will need to increase to $6.4 billion (95% UI $4.5–$9.0 billion) by 2020, $7.7 billion (95% UI $5.4–$10.9 billion) by 2025 and $8.7 billion (95% UI $6.0–$12.3 billion) by 2030. This translates to an annual cost of intensifying malaria control globally ranging between US$3.90 and US$4.40 per person at risk depending on the level of intervention coverage achieved. This falls within the broad range of per capita estimates published previously.43
Despite the large sums required to achieve the goals set out in the GTS, the intervention mix remains highly cost-effective. Under the strategy costed here, Griffin et al6 estimate, on average, that an additional 220 million cases will be averted annually. With this estimated to cost nearly $102 billion over the 15 years compared with $60 billion to sustain interventions at their current level, this translates to a cost per additional case averted of around $12. Furthermore, as many countries move towards elimination and subsequently progressively discontinue prevention interventions, the global costs are predicted to plateau towards the end of this 15-year period. Thus, accelerating progress towards elimination will see a move towards reducing the financial burden of malaria globally.
The costing approach developed here provides a methodology to monitor progress over the next 15 years and to identify shortfalls in the funding required to achieve the goals set out in the GTS. Our approach to estimate a global price tag for the global malaria strategy uses dynamic modelling to underpin forward projections of impact. A key benefit of this approach is that our investment targets account for malaria transmission dynamics and the effectiveness of combinations of interventions rather than of interventions implemented in silos.
We assume a slower but more realistic rate of increase in intervention coverage compared with previous studies, which projected reaching UHC within 2 years of intense scale-up.7 ,44 We predict increasing investment needs throughout the 15-year period compared with contemporary studies that assume decreasing needs from 2025 as large geographical areas achieve elimination.45 ,46 This difference is in part due to the substantial population growth projected over the next 15 years in high burden countries, such that, in our modelling, the reduced cost associated with elimination in a number of countries is counterbalanced at the global level by the increasing population size in those countries remaining endemic. The only scenario in which we estimate a reduction in global needs is if universal vector control coverage is scaled back once local elimination occurs. However, scaling back vector control in areas where local transmission has been interrupted is not recommended without a thorough evaluation of the epidemiological characteristics and capacities of health systems to detect and respond to potential reintroduction and resurgence,47 which in themselves may introduce other costs.
Our approach has a number of limitations. First, we did not include any constraints in the capacity of countries to scale up to high levels of coverage across all interventions. In reality, in many resource-poor settings, the lack of human resources or/and their poor productivity48 are likely important determinants of the effect and costs of malaria control strategies. This may therefore limit the potential impact of interventions. Furthermore, we only included the direct costs to the health system, and thus while we captured additional personnel time, associated human capital and infrastructure spending needed to increase the capacity of health systems was not included. Equally, we did not capture the savings to health systems that could be obtained from reducing the burden of malaria and hence potentially freeing capacity to treat other conditions. Second, we did not include the costs of near-term innovations that would most likely be required before 2030 to reach the GTS goals because of the uncertainty around the nature of these innovations and their implementation costs. Third, we did not estimate the additional costs of research and development for malaria as these have been estimated elsewhere (an additional US$673 million per year (range US$524–US$822 million)).5 Finally, we focused on the Sustainable Development Goal period and did not attempt to provide estimates post-2030 because of the increasing uncertainty in the type, effectiveness and costs of interventions.
Despite the substantial increase in financing towards malaria control and elimination over the past 15 years, we expect challenges in attaining the investment targets for 2016–2030. Relatively optimistic assumptions suggest that international and domestic contributions may increase to $3.8 billion by 2020,11 which implies a funding gap of $2.6 billion in this year. Only through significant increases in domestic and international funding, and in particular through economic growth and greater commitment to internationally agreed targets, could the current gap in financing begin to be bridged.11 While economic growth generates additional resources which can contribute to increasing government expenditure for health,49 ,50 countries at the highest risk of malaria are often the most resource-constrained and international funding sources are likely to continue playing a significant role in funding malaria interventions in the 2016–2030 period. Interlinkages between progress towards malaria elimination and economic wealth also imply that as countries get wealthier, they face graduation from donors' funding while successful malaria elimination requires predictable sustained funding to reach and sustain malaria-free status. These factors indicate that global malaria control and elimination face major challenges in the Sustainable Development Goal financing landscape. Ensuring the efficient use of currently available resources to maximise value for money should therefore be a priority, with a focus on the most effective interventions targeted to the populations most in need.