The billion-dollar malaria moment

Mark Grabowsky | 28 Feb 2008
Nature

Several years ago, I was explaining the value of a measles-vaccination campaign to a doctor at a paediatric hospital in northern Uganda, where, at that time, measles was endemic. The proposed campaign would control the disease and potentially enable the hospital to close the measles ward. The doctor responded that if there was also a campaign that controlled malaria he could "close the entire hospital".

There is still no vaccine for malaria, but Uganda has adequate resources — as do many other countries — for a national campaign of several malaria interventions, including insecticide-treated bed nets and effective drugs. The challenge is to scale-up those services. Just as high levels of vaccination coverage led to closing Ugandan polio and measles wards, rapid scale-up of prevention measures could end the malaria crisis in Africa. Slashing malaria cases and deaths would also free up vital resources for other diseases that have had too little attention for too long.

This vision is in stark contrast to the experience of recent decades, which have seen flagging global efforts and rising mortality from malaria. For a disease that still kills a million people a year, uses almost half of the clinic services in Africa, and reduces economic growth by up to 1%, controlling malaria may be the most important challenge in global public health.

But hope is arriving in Africa. The malaria crisis is starting to yield to new tools and strategies made possible by a substantial increase in resources over the past ten years — from less than US$100 million to about $1 billion this year. With most resources coming from a few donors, such as the Global Fund to Fight AIDS, Tuberculosis and Malaria, the World Bank and the President's Malaria Initiative, the current global goal — coordinated by the Roll Back Malaria (RBM) Partnership — is to halve the number of malaria deaths by 2010. However, these donors rely on a country-led process of planning and goal setting, and many nations' plans are not yet sufficiently ambitious in scope, intensity or timeliness to reach the 2010 target. Adequate funding for malaria control is an important first step, but unprecedented coordination, planning and operational support will be required to achieve the goals.

Recent progress has come from applying four interventions: sleeping under insecticide-treated bed nets, spraying houses with insecticides, preventive treatment for pregnant women, and timely treatment of the sick with effective drugs. The RBM target is to reach 80% coverage with each of these interventions by 2010. Within one year of scaling-up these interventions in 2006, malaria hospital admissions of children fell by more than about 60% at selected facilities in Ethiopia(1), Rwanda(1), Zanzibar(2) and on the coast of Kenya(3). Achieving the overall targets for Africa by 2010 is a huge challenge, and scaling-up drug treatment is particularly daunting, but the widespread use of bed nets should reduce case numbers and ease the demand for drugs.

In response to this initial progress, the leading public-health agencies attending the Bill and Melinda Gates Foundation malaria forum in Seattle last year boldly endorsed eliminating malaria as a public-health and economic problem. Bill and Melinda Gates went further and called for malaria eradication. But achieving eradication is a decades-long project that will require new tools, including an effective vaccine.

Integrated prevention

The malaria community can learn a great deal from the scaling-up of vaccination programmes for polio and measles. Ten years ago, about half-a-million children died of measles annually in Africa and many countries were endemic for polio. Since then, hundreds of millions of doses of vaccines have been delivered, and cases and deaths for both diseases have fallen by more than 90%. Despite the lack of a malaria vaccine, these successes can serve as an important model and inspiration for rapid scale-up.

Taking advantage of the existing delivery systems for childhood vaccination is the most efficient method for rapidly scaling up malaria prevention. Measles vaccination campaigns occur every three years in most African countries. During these week-long campaigns, children under five years of age are vaccinated — these are the same children that need insecticide-treated bed nets. Giving out free bed nets to children and their caretakers when they attend the measles campaigns achieves rapid, high and equitable bed-net coverage at low cost(4). These integrated campaigns are now the most common method for providing bed nets to Africans, with more than 40 million delivered over the past two years. During one week in December 2007 in Mali, more than 2.1 million nets were delivered along with measles vaccination, vitamin A and deworming medicine.

Even though periodic mass campaigns can rapidly achieve high coverage, because children are born every day, there is a need for ongoing bed-net distribution between campaigns. This can happen when a mother brings a child to a clinic for routine vaccination(5). There are twenty countries in sub-Saharan Africa where infants have at least four vaccination visits to the health centre in the first year of life. But these visits are rarely used for malaria prevention. In Nigeria, where vaccination coverage of measles is close to 70%, bed-net coverage is less than 10%. If these vaccination visits were used to give out bed nets, coverage would eventually rise to near target levels.

There are also opportunities for malaria prevention when pregnant women come to a clinic for pre-natal care. Countries need to adopt these proven and efficient approaches to integrated delivery. This requires national malaria-control programmes to coordinate more with their colleagues involved in other health programmes.

The challenge of treatment

Malaria prevention can build on these existing strategies, provided that countries and donors pull together. But of the four 2010 targets, achieving 80% rates of drug treatment is the greatest challenge. The difference in the ability to deliver prevention and treatment is illustrated in Sierra Leone. In 2006, in eight districts supported by the Global Fund, bed-net delivery was integrated into existing prevention services, and drugs and diagnostic kits were supplied to health centres.

After one year, 80% of children and 60% of pregnant women in Sierra Leone slept under a bed net. Virtually every clinic had adequate stocks of the recommended drugs for malaria treatment. However, only 4% of the children with malaria symptoms received appropriate treatment in a timely fashion (within one to two days of fever onset).

Malaria is a disease of poverty. Three-quarters of the population in rural Africa lives in extreme poverty, as defined by the family only having the income to buy enough food to ward off starvation. Free services at health facilities do not remove other barriers to reaching a clinic, such as transportation, or taking time away from work, growing food or fetching water. Integrating treatment into clinic-based services, even if low-cost or free, will fail to reach many of the poorest. Improved access will require new approaches that are not clinic-based.

One proposal is to subsidize drugs at private pharmacies(6). In theory, patients will benefit from local access to such shops and the presumed effects of private-sector competition to lower prices. Better consumer education, such as placing recommended prices on product labels, may also improve access. But recent findings suggest that this may still not be enough to reach those with other barriers to access, particularly children in poor families.

Evidence from pilot projects in Africa shows that new drugs can be effectively delivered to rural children within 48 hours of fever onset through either community-based volunteers or home-treatment kits(7). But can such approaches achieve the ambitious 2010 targets? One example of success is in Ho District in Ghana where community workers — usually farmers and teachers selected by the community — were able to correctly deliver drugs to 75% of sick children(7). But whether resource-poor government services can support civil efforts in malaria care is unproven. Partnering with community-based groups such as the Red Cross may be the key to large-scale implementation. The Global Fund, therefore, encourages governments and civil society to submit coordinated but separate applications so they do not compete for resources.

As countries pursue the 80% coverage targets, data are needed to relate coverage to the more important goal of halving deaths caused by malaria. In areas of moderate transmission — such as the Kenyan coast — even modest bed-net coverage may be able to reduce mortality by 50%. In areas of intense transmission, that may not be enough. The only way to routinely relate coverage to impact is through systematic disease surveillance. Routine and standardized monitoring is essential for a business-like approach to decision-making, but no such systematic surveillance data exists for malaria.

Monitoring is essential to protect our tools. Resistance to the pesticide DDT and the drug chloroquine contributed to abandoning malaria eradication in the 1960s. Today's efforts also depend on two molecules: pyrethroids to treat bed nets and artemisinin for treatment. Resistance is widespread for the former and emerging for the latter. Moreover, more money for drugs invites counterfeits, as seen in Asia and now in Africa. Achieving the malaria-control goals, or elimination, risks failure if detection and response to resistance remain inadequate.

Secret weapon

In many ways, disease surveillance has been the secret weapon for polio and measles control, powering funding and informing decisions. An example is the regional monthly newsletter of measles cases. It allows countries, donors and planners to systematically monitor progress towards goals.

Without ongoing high-quality data it will be impossible to monitor progress and focus efforts on elimination or eradication. There are technical challenges to improving malaria surveillance, including the need to move away from presumptive to laboratory diagnosis. But most of these challenges can be resolved with adequate investment, training and management.

As the global community scales up malaria control, it must ensure that all countries have adequate monitoring systems in place. Nonetheless, a country-based approach by itself is neither technically nor financially appropriate. There must also be regional laboratory networks that support country efforts, apply standardized monitoring techniques, rapidly share findings and manage coordinated responses. This is particularly essential for monitoring drug quality. It would cost about $10 million annually to get useful, monthly, surveillance data and to support regional monitoring, laboratory and surveillance networks. Without it the billion-dollar malaria effort is flying blind.

1. http://www.who.int/malaria/docs/ReportGFImpactMalaria.pdf
2.
Bhattarai, A. et al. PLoS Med. 4, e309 (2007).
3. Okiro, E. A. et al. Malar. J. 6, 151 (2007).
4. Grabowsky, M. et al. Bull. World Health Organ. 83, 195-201 (2005).
5. Grabowsky, M., Nobiya, T. & Selanikio, J. Trop. Med. Int. Health 12, 815-822 (2007).
6. Institute of Medicine of the National Academies Board on Global Health. Saving Lives, Buying Time. Economics of Malaria Drugs in an Age of Resistance (Natl Acad. Press, Washington DC, 2004).
7. Ajayi, I. O. et al. Malar. J. 7, 6 (2008).

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