The economic burden of malaria — poverty and elimination
Malaria is an infectious disease caused by Plasmodium parasites, transmitted in tropical climates by Anopheles mosquitoes. Although malaria is now endemic mostly in low-middle income countries, in the not so distant past, malaria was a public health threat also in the southern states of the United States. Extensive vector and ecological control around the World War II period, along with steady economic development, eventually allowed elimination of malaria in this part of the world (1).
Today, however, malaria continues to plague many of the worlds’ poorest countries. A highly effective vaccine is not yet available, despite many attempts to develop one. The efficacy of RTS,S, the only currently licensed vaccine, is variable across age groups and waning seems to be rapid (2). News recently emerged from the Oxford/AstraZeneca vaccine group behind the Covid-19 vaccine, who reported an unprecedented 77% efficacy in their recent trial of 450 participants in Burkina Faso (3), but this vaccine is not yet licensed and ready for production. Drug resistance is a perennially resurfacing problem, threatening to render current treatments ineffective.
Apart from the risk of illness and premature mortality, particularly in children, malaria is considered to have a substantial impact on the broader economy. An analysis of Gross Domestic Product (GDP) of 180 countries in the period 2000 to 2017 suggested a 10% reduction in malaria incidence was associated with an average increase of 0.3% in GDP/capita and a higher GDP growth rate (4). This raises the question of how countries might fare if they manage to eliminate malaria. The 2020 World Health Organization report Malaria eradication: benefits, future scenarios & feasibility (5) summarises results from mathematical and economic modelling studies answering this question. Economic impacts are expected to materialise through labour supply (reduced morbidity and mortality) and physical capital accumulation (enabled by reduced spending on malaria programmes), which in turn affect national wealth. Focusing on the 29 endemic countries which account for the vast majority of malaria cases, scaled up malaria intervention coverage was estimated to avert 2 billion malaria cases and 4 million deaths before 2030. These health impacts were estimated to yield a 0.17% gain in national income, equivalent to US$ 283 billion during 2016–2030 (5).
For the technically inclined, these results were estimated using the Economic Projections of Illness and Cost (EPIC) model, developed by WHO and described in Annex 2 of the Technical Report of the Department of Health Systems Governance and Financing: Investing global, investing local: supporting value for money towards the health SDGs (6). The results are based on a modified Solow growth model, a model that estimates growth in economic output over time as a result of changes in capital accumulation, labour/population growth and technological progress. As an input to this, the direct impact of scaled-up malaria interventions on morbidity and mortality was estimated using a dynamic transmission model for malaria.
Regardless of the magnitude of economic impact, malaria is a global epidemic that has been lingering for centuries, impacting human health and development. In the past few decades, technological progress has yielded a diverse tool box to deal with the epidemic in an effective and cost-effective way, but progress towards elimination remains slow. Apart from the multi-faceted challenge of dealing with a vector-borne infectious disease, malaria is to some extent a disease of poverty, with transmission exacerbated by e.g. poor housing, living near open bodies of water, and by lack of access to effective healthcare. In their study of the impact of urbanisation on malaria transmission, Hay et al. conclude “the dual effects of behavioural changes and transmission reduction that are associated with urbanization make for profound decreases in morbidity and mortality from malaria in Africa” (7). As such, as long as vast segments of the world population are kept in poverty, malaria will continue its onward march.
This World Malaria Day, in a year where a global pandemic has severely dented economic growth and ripped through societies with less prepared health systems, more than ever we recognise the bi-directional relationship between health and wealth. Increasing access to effective malaria interventions remains a moral imperative. But amidst financing and programming efforts, keeping one eye on broader economic development and fair distribution of wealth and resources should be a cornerstone in the elimination of infectious disease threats.
References:
Elimination of malaria in the United States (1947–1951): https://www.cdc.gov/malaria/about/history/elimination_us.html
The quest for a vaccine against malaria: https://www.nature.com/articles/d42859-020-00021-8
Sarma N, Patouillard E, Cibulskis RE, Arcand JL. The economic burden of malaria: revisiting the evidence. Am J Trop Med Hyg. 2019;101:1405–15. doi:10.4269/ajtmh.19–0386.
Investing global, investing local: supporting value for money towards the health SDGs: https://www.who.int/docs/default-source/investment-case/value-for-money.pdf
Hay, Simon I., et al. “Urbanization, malaria transmission and disease burden in Africa.” Nature Reviews Microbiology 3.1 (2005): 81–90.
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