The Global Crisis of Malaria: Report on a Yale Conference

Abstract

An international conference, “The Global Crisis of Malaria: Lessons of the Past and Future Prospects,” met at Yale University, November 7-9, 2008. The symposium was organized by Professor Frank Snowden and sponsored by the Provost’s office, the MacMillan Center, the Program in the History of Science and History of Medicine, and the Section of the History of Medicine at the Yale School of Medicine. It brought together experts on malaria from a variety of disciplines, countries, and experiences — physicians, research scientists, historians of medicine, public health officials, and representatives of several non-governmental organizations (NGOs). An underlying theme was that much could be gained from a big-picture examination across disciplinary frontiers of the contemporary public health problem caused by malaria. Particular features of the conference were its intense scrutiny of historical successes and failures in malaria control and its demonstration of the relevance of history to policy discussions in the field.

The world continues to experience a major ongoing emergency. Forty percent of humanity is at risk of infection every year from malaria, which is endemic in more than 100 countries. Five hundred million people a year become seriously ill with malaria, and more than a million, primarily children younger than five and pregnant women in sub-Saharan Africa, die¹.

The burden of malaria, however, is heavier than the statistics for mortality and morbidity suggest. It is a terrible complication of pregnancy, leading to high rates of miscarriage, maternal death through hemorrhage and severe anemia, and all the sequelae that follow from severe low birth weight. Since malaria can be transmitted transplacentally from mother to fetus, it also can lead to the birth of infants who are congenitally infected. Since malaria is a major immunosuppressive disease, it works in devastating synergy with the ongoing pandemics of HIV/AIDS and tuberculosis, and malaria victims are highly susceptible as well to respiratory infections such as influenza and pneumonia.

In those areas of the tropical world where malaria is hyperendemic and transmission continues throughout the year, the population at risk can be infected, reinfected, or superinfected every year. If they survive, the victims possess a painfully acquired partial immunity, but it comes at a high and enduring cost because repeated bouts of malaria lead to severe neurological deficit and cognitive impairment. The results are ineradicable poverty, illiteracy, compromised economic growth, a stunted development of civil society, and political instability. In the words of Ronald Ross, the Nobel Prize laureate who discovered the mosquito theory of transmission, malaria enslaves those it does not kill [1]. Malaria is a major contributor to the inequalities between North and South, and of the dependency of the Third World. Furthermore, environmental degradation, poverty, climatic change, overpopulation, and complex emergencies continue to generate the conditions under which malaria thrives. Professor Brian Greenwood of the London School of Hygiene and Tropical Medicine provided extensive analysis of the current situation in The Gambia as a specific and important example.

The situation of contemporary crisis is paradoxical because the early decades following the Second World War marked a period of unrestrained optimism in the international scientific and public health communities. In part, this optimism was a reflection of a generalized medical hubris. By the 1950s, medical science seemed to be on the verge of a final triumph over all communicable diseases. Vaccines promised global elimination of smallpox, diphtheria, and polio; public health infrastructures such as sewage systems, the sand filtration and chlorination of water, and the pasteurization of milk suggested the conquest of such water- and food-borne scourges as typhoid, salmonellosis, and dysentery; the discovery of the antibiotics penicillin and streptomycin suggested the end of tuberculosis and syphilis; and the discovery of powerful new pesticides led many to predict the swift end of vectorborne diseases, including malaria, dengue fever, sleeping sickness, typhus, and yellow fever. Communicable diseases, it was believed, were on the verge of being eradicated from the globe. In the words of the U.S. Surgeon General William H. Steward in 1969, the time had come to close the book on infectious diseases. With heady and premature optimism, E. Harold Hinman wrote the influential work World Eradication of Infectious Diseases [2]. Such unbridled euphoria produced the theory of the “disease transition,” which held that the world stands poised to escape the long millennia of plagues and pestilence in order to enter an era when the only diseases to afflict mankind will be chronic and degenerative ailments such as heart disease and cancer².

Ironically, the disease that initiated this postwar optimism was malaria, thanks to the development of an apparent panacea — DDT. The most influential proponent of DDT was Paul Russell, the eminent malariologist, who published Man’s Mastery of Malaria in 1955, in which he proclaimed the “era of DDT” and predicted a swift global victory over the ancient scourge [3]. Adopting Russell’s optimism as policy, the eighth World Health Assembly, meeting in Mexico City in May 1955, launched an unprecedented and ambitious campaign of worldwide eradication based on the power of the new weapon and its standardized four-stage program of “preparation, attack, consolidation, and maintenance” [4].

Unfortunately, the lofty vision of 1955 rapidly ran into insoluble difficulties. Mosquitoes developed resistance to the hydrocarbon. In addition, the political will needed to provide adequate funds for the project and to overcome the inevitable difficulties it encountered proved inadequate. Paradoxically, the very announcement of an easy and rapid victory undermined the campaign by discouraging researchers, donors, and physicians from entering a field that was so soon to become redundant. It became a standard witticism that the World Health Organiation (WHO) campaign had eradicated not malaria, but malariology. The malarial problem revealed itself to be more intractable than the DDT enthusiasts had imagined. By the end of the 1960s, the idea of a global eradication of malaria had become a mirage that was as distant as ever, and the entire program collapsed in disillusionment and confusion³.

Since 1969, the crisis has deepened. A variety of factors have tipped the balance in favor of the parasites and the anopheline mosquitoes that serve as their vectors. These factors include the development of drug resistant plasmodia; wars, migrant labor, and the displacement of people; the synergy between malaria and the co-epidemics of HIV/AIDS and tuberculosis; development projects such as building dams and clearing forests that have degraded the environment and created opportunities for mosquitoes; the Darwinian adaptation of the major vector Anopheles gambiae to urban habitats; the persistence of poverty and substandard housing that place humans at risk from arthropods; and climate change. It also has been all too easy for the industrial West to ignore an issue that primarily affects the inhabitants of distant and resource-poor nations of the tropical world.

Professors Randall Packard of Johns Hopkins University and Darwin Stapleton of the Rockefeller Archive Center carefully traced the history of WHO’s eradication program, its failure, and the legacy of that failure for the present. Other historians, such as Professors Mark Harrison and Margaret Jones of Oxford University, Socrates Litsios of the WHO, and James Webb of Colby College traced the antimalarial campaigns in India, Jamaica, and tropical Africa.

Fortunately, recent years have witnessed a renewed awareness of the appalling magnitude of the burden of physical and emotional suffering, economic hardship, neurological deficit, and death caused by malaria. There is also a recognition that, in a global world, the social and economic problems and the resulting political instability of countries in the tropical world have a profound effect on the security and future economic prospects of the industrial world. Enlightened self-interest has promoted acknowledgment that, under the right combination of circumstances, malaria could return to countries and regions from which it has been eliminated, including the United States and Western Europe. Thus, after an extended period of relative neglect and underfunding, a recent wave of support has provided new impetus for control measures and for research to develop new tools to combat the disease. Leading examples of the new commitment to tackle malaria are the major commitments of resources by the President’s Malaria Initiative of President George W. Bush and by the Bill and Melinda Gates Foundation.

Existing approaches are being applied on an unprecedented scale. Dr. Oliver Sabot of the Clinton Foundation, Dr. Janice Culpepper of the Gates Foundation, Dr. Mary Galinski of the Malaria Foundation International, Professor Rick Bucala of the Yale School of Medicine, Professor Gilberto Corbellini of Rome University, and Dr. Dana Dalrymple of USAID explained the strategies being adopted in the antimalarial campaign. These measures include health education and awareness, insecticide-treated mosquito nets, residual spraying with DDT, and treatment by means of Artemisinin Combined Therapies. At the same time, funding has increased for research to develop new tools to combat the disease. Dr. Thomas Richie of the U.S. Naval Malaria Vaccine Development Program discussed the present position with regard to the effort to develop an effective vaccine and the difficulties that make progress difficult. Dr. John Carlson of Yale discussed the genetic research being conducted in his lab to develop antivector strategies by modifying the olfactory sensors of anopheles mosquitoes, and Dr. Manuel Lluberas discussed other vector control strategies. It was agreed by all that there is urgent need to make use of all available resources in a rational and integrated strategy to reduce the unacceptably high mortality, particularly in Africa, where a child dies every 30 seconds from a disease that, in principle, is both preventable and treatable.

The symposium devoted its final session to drafting a resolution that would incorporate the consensus of the conference with regard to the lessons that have been learned and the appropriate priorities for the ongoing antimalarial effort. The purpose was to make use of the expertise at the conference to make recommendations to such major participants in the global campaign as the Gates Foundation and the President’s Malaria Initiative. The recommendations of the conference were the following:

1. The President’s Malaria Initiative (PMI) should appoint a board of experienced advisers, including experts with historical knowledge and experts on malaria in Africa. As an internationally recognized organization of specialists, the American Society of Tropical Medicine and Hygiene also should appoint an advisory panel of persons with relevant experience of malaria control. The advice of this panel should be offered to the PMI and the NGOs in the field. We further suggest that NGOs involved in the antimalarial campaign appoint boards of experienced and historically informed advisers to oversee their programs and make recommendations. An understanding of past malaria control efforts is important if earlier mistakes are to be avoided.

2. All antimalarial efforts should be tailored to the specific needs of individual countries, taking due account of their health infrastructure, epidemiology, ecology, and political realities. Inevitably, success will depend strongly on national stability and economic health. The long-term goal of PMI and other outside institutions should be to shift implementation to indigenous institutions such as National Malaria Control Programs, which will require support and augmentation by PMI and other funding agencies.

3. Research aimed at the development of new tools in the struggle such as vaccines, vector control technologies, and medications should be adequately funded in an ongoing manner, but without delaying the rational use of already available methodologies.

4. Planning should empower individuals, local authorities, and national health ministers by educating them about malaria. Top-down and one-size-fits-all approaches must be carefully avoided.

5. A vital function of the health infrastructure must be the rigorous monitoring of mosquitoes, parasite prevalence, and other malariometric indices. These locally collected data should be the basis for planning and for evaluating results. The PMI and other agencies involved in malaria control should establish and strengthen national laboratories with trained and qualified local staff to generate this information for local use.

6. There should be no illusion of rapid success against malaria, perhaps the oldest of human diseases, because unrealistic targets and unsustainable goals carry the dangers of fatalism and the abandonment of the effort. Once begun, the campaign must be sustained. Otherwise, there is the risk that temporary but unsustainable advances could have unanticipated, negative consequences. These could include promoting mosquito and parasite resistance and compromising acquired immunity. Devastating epidemics could then ensue as has happened in the past. Strategies setting priorities should be gradually developed into long-term public health efforts that can be maintained at regional levels rather than dramatic but temporary interventions.

7. The capacity of the WHO to coordinate multilateral efforts and to support national control programs should be strengthened and made effective.

Past efforts at controlling and eliminating malaria have been undermined by poorly designed development projects, armed conflicts, population dislocations, the inability of resource-poor nations to sustain control programs, and levels of poverty that prevent populations from having access to preventive or curative measures. Successful malaria control and elimination demand tremendous patience, vision, and long-term commitment.

Since the conference, the resolution has been received by the Gates Foundation and the PMI, which have both agreed to discuss the views of the symposium and, where appropriate, to be informed by them in their antimalarial practice.

Further reading

For further readings on malaria, see Margaret Humphreys, Malaria: Poverty, Race and Public Health in the United States (Baltimore, 2001); Socrates Litsios, The Tomorrow of Malaria (Karori, New Zealand, 1996); Packard, Making of a Tropical Disease; Ross, Prevention of Malaria; and Frank M. Snowden, The Conquest of Malaria: Italy, 1900–1962 (New Haven, 2006).

Abbreviations

NGO

non-governmental organization

WHO

World Health Organization

PMI

President's Malaria Initiative