Please can you outline the malaria control strategies that have been implemented over the last decade?
Exciting progress has been made in the global fight against malaria. The malaria map continues to shrink each year; in the last ten years four countries have been certified malaria-free, and thirty-four additional countries are now working towards malaria elimination targets.
The global malaria eradication strategy, as outlined in 2008 by the Roll Back Malaria Global Malaria Action Plan, calls for a three part strategy:
- Aggressive malaria control in the areas that are hardest hit with malaria, using the best tools available, such as indoor residual spraying, long-lasting insecticide treated nets, and prompt diagnosis and treatment of malaria with artemisinin-based combination therapies (ACT).
- Progressive elimination of malaria in countries where possible, to shrink the malaria map.
- Research and development to bring forward new tools, such as new drugs, diagnostics, and a vaccine.
All three parts of this strategy must continue to be pursued simultaneously. All are important, and all contribute to the overarching goal of a world free from malaria.
How successful have these malaria control strategies been?
The World Health Organization estimates that due to aggressive malaria control using the best interventions available, over one million lives have been saved since 2000, and in the last 5 years alone, deaths from malaria in Africa have decreased by 33%.
These dramatic reductions in malaria burden around the world, including in sub-Saharan Africa, illustrate the success of global commitments to malaria control in recent years.
Your recent research suggested that malaria control strategies must evolve to keep up with the changing patterns of malaria infection. Please can you explain how malaria infection patterns are changing?
Malaria transmission is a fast moving and changing target, and we must be prepared to shift our strategy and adapt interventions to continue shrinking the malaria map.
In eliminating countries, malaria is becoming clustered into small geographical areas (we call these hotspots) or clustered demographically into subpopulations with shared social and behavioral risk factors for malaria (we call these hot-pops).
We also know that malaria is increasingly imported into low transmission settings from high endemic areas, and that a higher proportion of cases are caused by Plasmodium vivax in settings outside of sub-Saharan Africa.
The challenge is to track these changes in epidemiology and to target and adapt interventions more effectively.
How do you think malaria control strategies should be altered to keep up with the changing malaria infection patterns?
There is a need to re-strategize around how to best detect and target cases and infections, in low transmission settings, and particularly within hotspots and hot-pops.
Building robust surveillance and response systems can help national malaria control programs do this, allowing them to monitor and respond to the epidemiologic situation on the ground.
Additionally, it is critical that we develop novel tools that can address these changing trends. For example, occupation-based infection control methods that protect people that are often outside their home – such as insecticide-treated clothing or hammocks – are being developed to help protect migrants or labourers working in high-risk settings.
It is also likely that we will see much greater use of targeted mass drug administration to clear the residual parasite pool in asymptomatic individuals, especially in elimination settings.
Why when malaria is reduced to low levels does it become increasingly concentrated in particular places or communities?
As malaria decreases, cases become clustered into geographical hotspots where groups of people, or individual households, have higher malaria transmission compared to others.
The same can happen within the larger population. For example, groups with specific occupations (hot-pops), such as rubber tappers or soldiers living and working in the forest, are at higher risk for malaria.
These hotspots and hot-pops are more at risk for a variety of reasons, including marginalization for geographic, economic and political reasons, or due to poverty, lack of access to health care and/or high mobility.
They may lack of access to malaria control interventions, live or work close to mosquito breeding sites, or have poor housing, putting them at greater risk for malaria than others.
Why do some groups of people avoid accessing health systems for malaria treatment? What can be done to help provide malaria treatments to these hard-to-reach populations?
At-risk populations are vulnerable in many ways, and might avoid accessing the health system for several reasons, including the high cost of treatment, fear of unwanted attention from government authorities that may be alerted by health workers, geographic lack of access, or low knowledge or perceived risk of malaria.
While ensuring universal access to a robust health system is ideal, national malaria control programs can also develop targeted systems to detect and treat cases in these populations.
Do you think vaccines will be important in the eradication of malaria?
We know that disease eradication is incredibly challenging, with or without a vaccine. Would an effective malaria vaccine help us reach eventual eradication? Without a doubt, yes. However, advances in malaria drugs will also play a critical role in elimination and eventual eradication.
It is essential that we use today’s tools effectively while investing in the research and development needed to build new tools to support malaria control and elimination in the future.
How can you predict malaria infection patterns going forward?
We will continue to see large numbers of malaria cases in children under five and pregnant women in the malaria heartland, particularly in sub-Saharan Africa.
However, as countries reduce their malaria burden, we anticipate that they will follow similar epidemiologic trends to those described above: malaria will become increasingly male, adult, imported and, outside sub-Saharan Africa, caused by P.vivax.
As readers will know, P.vivax is harder to detect and treat than P. falciparum and typically proves to be the more stubborn parasite in elimination settings.
Are you concerned about the allocation of funding for malaria control?
Absolutely. We have seen a flat-lining of malaria funding in recent years. The World Health Organization estimates that there is an annual shortfall of around USD $3 billion for malaria control. Filling this gap is critical.
Malaria-eliminating countries are particularly susceptible to funding changes. When countries reach a low malaria burden, their governments may reallocate funding and resources to other pressing priorities.
A recent review of historical malaria resurgences noted that, of the 75 resurgence events documented since 1930, almost all were attributed at least in part to the weakening of malaria control programs. When cases are low, it is exactly the time when funding must be maintained to make the final push to elimination.
For all these reasons the full replenishment of the Global Fund in 2013 is critical. Without this, our goals for malaria control, elimination and eventual eradication will be put in jeopardy.
Where can readers find more information?
Online resources:
- http://www.shrinkingthemalariamap.org/about/malaria-elimination-group
- https://www.ucsf.edu/
Academic resources:
- Cotter, C., Sturrock, H., Hsiang, M., Liu, J., Phillips, A., Hwang, J., Smith Gueye, C., Fullman, N., Gosling, R., Feachem, R. The changing epidemiology of malaria elimination: new strategies for new challenges. The Lancet 2013.
- Cohen JM, Smith DL, Cotter C, Ward A, Yamey G, Sabot OJ, Moonen B. Malaria resurgence: a systematic review and assessment of its causes. Malaria Journal 2012; 11: 122.
- Feachem RGA, et al. Shrinking the malaria map: progress and prospects. Lancet 2010; 376(9752): 1566-78.
About Sir Richard Feachem
Richard G A Feachem is Director of the Global Health Group at UCSF Global Health Sciences, Professor of Global Health at both the University of California, San Francisco and the University of California, Berkeley. He is also a Visiting Professor at London University and an Honorary Professor at the University of Queensland.
From 2002 to 2007, Sir Richard served as founding Executive Director of the Global Fund to Fight AIDS, Tuberculosis and Malaria and Under Secretary General of the United Nations. During this time, the Global Fund grew from scratch to become the world’s largest health financing institution for developing countries, with assets of US $11 billion, supporting 450 programmes in 136 countries.
From 1999 to 2002, Professor Feachem was the founding Director of the Institute for Global Health at UCSF and UC Berkeley. From 1995 until 1999 Dr. Feachem was Director for Health, Nutrition and Population at the World Bank. Previously (1989-1995), he was Dean of the London School of Hygiene and Tropical Medicine. Professor Feachem served as Chairman of the Foundation Council of the Global Forum for Health Research; Treasurer of the International AIDS Vaccine Initiative; Council Member of Voluntary Service Overseas; and on numerous other boards and committees. He was a member of the Commission on Macroeconomics and Health, and the Commission on HIV and Governance in Africa. He has worked in international health and development for 40 years and has published extensively on public health, health policy and development finance.
Professor Feachem holds a Doctor of Science degree in Medicine from the University of London, and a PhD in Environmental Health from the University of New South Wales. In 2007 he was awarded an Honorary Doctorate in Engineering by the University of Birmingham. He is a Fellow of the Royal Academy of Engineering and an Honorary Fellow of the Faculty of Public Health Medicine of the Royal College of Physicians and of the American Society of Tropical Medicine and Hygiene. In 2002 he was elected to membership of the Institute of Medicine of the US National Academy of Sciences. Sir Richard was knighted by Her Majesty Queen Elizabeth II in 2007. He was awarded the 2010 Sir Frank Whittle Medal by the Royal Academy of Engineering.
Mosquito males’ visual and auditory cues reveal new insights for malaria control