Rolling back malaria: opportunities and challenges

In recent months the world has experienced a wake-up call about the gravity of the malaria situation in Africa and much of the rest of the developing world. Western governments, business leaders, journalists, and even film stars have called for greater resources to reduce the malaria toll for the globe's poorest people. It is a good moment to take stock of the progress we have made, what we have learned and the challenges we face.

The Roll Back Malaria (RBM) initiative was launched by WHO, the World Bank, UNICEF and the United Nations Development Program (UNDP) in 1998, at a time of recognition that the malaria situation in the world, especially in Africa, was deteriorating and in the face of evidence that deployment of insecticide-treated nets and other preventive measures could reduce mortality. During its first four years, the RBM partnership – consisting of malaria-endemic countries, their bilateral and multilateral development partners, the private sector, non-governmental and community-based organizations, foundations and research and academic institutions – functioned as a loose network of stakeholders with the shared goal of reducing the burden of malaria by half by the year 2010 through evidence-based action. The work of the partnership resulted in greatly increased awareness of malaria, with the inclusion of the disease in the portfolio of the Global Fund to fight AIDS, Malaria and Tuberculosis (GFATM) as one of the most important results. The impact at country level was, however, limited (Final report of the External Evaluation of Roll Back Malaria; Malaria Consortium, 2002).

In 2003, the partnership took on a more formal governance structure. Now overseen by a board, it consists of: sub-regional networks; country partnership advisers; high-profile champions; working groups for establishing consensus on best practices for scaling up; and a secretariat, located at WHO headquarters, whose mission is to ensure that contributions from individual partners are coordinated and focused on the needs of countries and in line with best-practice recommendations and technical norms and standards. The WHO Roll Back Malaria Department, working with WHO's Regional Offices and in Headquarters, especially with the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), is devoted to developing norms and standards based on scientific evidence and expert consensus, as well as monitoring and evaluation, country support and capacity development.

The fundamental elements of malaria control are well established, and include: (1) prompt and effective treatment of all malaria cases; (2) prevention, in most cases by vector control through the use of insecticide-treated mosquito nets, indoor residual spraying or other methods; (3) protection of pregnant women through intermittent preventive treatment in areas of stable malaria transmission; (4) prevention of, and timely responses to, epidemics (WHO Expert Committee on Malaria, 2000).

1 Promising developments

Because of recent enhancements in prevention, diagnosis and treatment, there are now much better possibilities than before for making rapid gains in the fight against malaria. Among the most important ones are artemisinin-based combination therapies, rapid diagnostic tests and long-lasting insecticidal nets.

For more than a decade the increasing resistance of Plasmodium falciparum to conventional treatments such as chloroquine, sulfadoxine–pyrimethamine (SP) and amodiaquine has presented a huge challenge to malaria control efforts and has probably been the main cause of the increase in malaria mortality observed in eastern and southern Africa (Korenromp et al., 2003). Artemisinin-based combination therapies (ACTs) have been shown to be highly effective; there are good reasons to assume that their universal use will slow down the development of resistance and exert a significant impact on malaria morbidity and mortality. Still, there is work to be done to make these drugs more widely available and affordable (Institute of Medicine, 2004).

Although increased production volumes of ACTs will lead to lower prices, these treatments will remain relatively costly, which means that there is a greater rationale for investing in diagnosis. While light microscopy remains the gold standard, the rapid diagnostic tests (RDTs) are probably the best alternative in remote areas, as they can be used by health workers with limited training and require little supervision. There are still problems of variable quality and shelf life, which must be solved by research and development (WHO, 2004). In areas of very intense transmission, the benefits of RDTs in young children are uncertain, because of the high parasite prevalence in asymptomatic carriers. Furthermore, there is insufficient evidence to recommend withholding treatment in children under 5 years of age with clinical presentation of malaria, on the basis of negative parasitological results, whether from microscopical examination or RDTs.

However, over the coming years, transmission should gradually become reduced, especially through sustained, high coverage of insecticide-treated nets (Lindblade et al., 2004). Randomized controlled trials in Africa have shown that this intervention can reduce deaths in children under 5 years by 17% and severe malaria cases by 45% (Lengeler, 2004). When used by pregnant women, insecticide-treated nets are also efficacious at reducing maternal anaemia, placental infection and low birth weight (Garner and Gulmezoglu, 2003).

The conventional mosquito nets that were the object of these studies need retreatment every 6 to 12 months, and maintaining high retreatment rates has proven difficult, especially if people have to pay for the insecticide. Long-lasting insecticidal nets – with insecticide incorporated directly in the net's fibres – eliminate the need for regular retreatment and remain effective for at least 4 years. Two long-lasting nets have been approved by WHO (WHO, 2001, 2003). Their price is not much higher than conventional treated nets, so that over a period of a few years they are less costly, in addition to being far easier to implement. Thus, this technical advance holds great promise for scaling up coverage.

2 Progress and challenges

Between 2001 and the end of 2004, 40 malaria-endemic countries adopted ACTs as a first- or second-line malaria treatment, and an additional dozen are in the process of changing their policies. Supplying countries with ACTs has been a challenge because artemisinin is derived from a plant, Artemisia annua, that has been grown almost exclusively in China and Viet Nam. The supply chain is further complicated by the fact that the finished product has a shelf life of only 2 years, making accurate forecasting and production planning essential. The sudden surge in demand in 2004 – a year during which 18 countries adopted ACTs – has left the production system straining to keep pace with demand, resulting in a shortfall late in 2004.

A rapid scale-up in cultivation of the plant and capacity to process it are crucial to worldwide malaria control efforts. WHO, UNICEF, GFATM and other RBM partners are working with ACT manufacturers to identify mechanisms to ensure sufficient supply of quality products. One promising development is the initiation of large-scale cultivation in Kenya and Tanzania in 2005.

A scale-up in production of long-lasting insecticidal nets is also crucial. Manufacturers of the permethrin/polyethylene and deltamethrin/polyester nets estimate that production will reach more than 2.5 million nets per month in late 2005.

Availability of these vital commodities will not guarantee access, however. ACTs cost over 10 times the price of conventional monotherapies and are beyond the reach of most people who need them. Even conventional insecticide-treated nets are too costly for those who would most benefit from their use.

International assistance is therefore essential. In its first three rounds of funding, GFATM allocated US$942 million for malaria control in 59 countries. Early in 2004, the GFATM board approved an additional amount of US$900 million for 23 malaria components, bringing its total malaria allocations to US$1.8 billion, to be spent over 5 years.

This funding is a leap forward, but it is insufficient for the large-scale malaria control programme that is needed. WHO estimates that an annual expenditure of US$2 billion would be needed for malaria control in Africa and an additional US$1 billion for programmes elsewhere.

Even with full funding, malaria control would face hurdles because of a human resources gap. The majority of malaria-endemic countries, particularly those in Africa, are desperately short of health-care personnel. Many countries, however, with the support of WHO and other RBM partners, are engaged in stepped-up training in malaria recognition and treatment for community health workers, such as traditional birth aides, local shopkeepers and home care-givers. However, a more ambitious plan for solving Africa's human resources crisis remains crucial.

Another promising development is the growth of programmes aimed at delivering anti-malarial prevention (insecticide-treated mosquito nets, intermittent preventive treatment for pregnant women) in concert with other public health interventions: in particular, national immunization programs. Campaigns combining insecticide-treated net distribution with immunization campaigns will take place in six countries this year through partnerships between WHO, the International Federation of Red Cross and Red Crescent Societies, UNICEF, the US Centers for Disease Control and Prevention, and other RBM partners. Experiences from a number of countries (such as Viet Nam, Ghana, Eritrea, Malawi, Togo, and Zambia) indicate that subsidized or free provision of treated nets to vulnerable groups in rural areas is associated with high rates of use.

The RBM Partnership has established a Malaria Medicines and Supply Service, which will work to remove obstacles to access for essential products such as ACTs, RDTs, insecticides and long-lasting insecticidal nets. This service will produce global supply and demand forecasts, interact with manufacturers, assist countries with procurement, and monitor funding needs. The supply service should help countries make the best possible use of funds and available prevention and treatment.

3 Conclusion

Malaria remains the number one killer of young children in Africa and a major cause of morbidity and mortality in people of all ages living in all endemic regions. Malaria control has been identified as one of the four most cost-effective approaches to relieving poverty (Lomborg, 2004).

Early in 2005 a generous outpouring of financial support and technical assistance were directed at the regions affected by the Indian Ocean tsunami. With great speed—just a few weeks after the disaster—those donations made possible a massive scale-up of malaria prevention and available treatments.

The rally to protect the tsunami survivors demonstrates what can be accomplished when financial means and human resources are put in place to battle malaria. If the same level of resources was summoned to fight the chronic malaria disaster that is crippling endemic countries, malaria could be more than ‘rolled back’. In the space of a single year, hundreds of thousands of lives could be saved.

© Royal Society of Tropical Medicine and Hygiene 2005