MALARIA: The Making of a Tropical Disease: A Short History of Malaria

The Making of a Tropical Disease: A Short History of Malaria by Randall Packard
Johns Hopkins University Press, 2008

Of all diseases, malaria is perhaps the one with the most subtle interplay with human history. It has long affected human beings, and has left its genetic mark on modern populations. Thalassaemia, glucose-6-phosphate dehydrogenase deficiency, sickle-cell trait, the Duffin antigen, and several other genetic variations owe their prevalence to the disease. The disease acted as a barrier to European imperialism and rendered many areas of the world, even in Europe, largely unproductive. Malaria thus influenced, and its incidence has been in turn influenced by, agricultural practices from time immemorial. It is perhaps the most ecologically sensitive of all human diseases.
This ecological imperative drives Randall Packard's powerful narrative in The Making of a Tropical Disease: A Short History of Malaria. He recounts the repeated impact of human activity on the incidence of malaria worldwide. In the American south, the Roman Campagna, the Indian Punjab, or the Brazilian northeast, the story was much the same. Agricultural practices created niches where the relevant Anopheles species could breed. Packard's most common trope is that of sharecroppers or subsistence farmers eking out a marginal living, with no resources and no incentive to improve the land. Malaria was especially cruel in that sometimes activities that ought to have been economically sound, such as crop irrigation or railroad building, could increase its incidence.
While discussing the common themes in the early history and incidence of malaria, Packard also emphasises that malaria is the most local of widespread diseases. This fact was dimly perceived in the traditional experience of “mal aria”, the quintessential disease of place. The reasons for this became clear only after the mosquito mode of its transmission was discovered at the end of the 19th century, by Ronald Ross (1857—1932), working in India, and Giovanni Battista Grassi (1854—1925), working in Italy, two malarious countries. In the decades that followed, the variable breeding habits and life-cycles of the many species of Anopheles that can spread malaria worldwide were gradually elucidated, as well as the reasons why strategies for malaria control had to be tailored to meet the variable social, economic, and ecological realities that were encountered.
The discovery of the role of Anopheles in the transmission of malaria created a period of optimism. The discovery that yellow fever, too, was transmitted by mosquitoes, and the successes in containing these two insect-borne diseases in Cuba, Panama, and elsewhere seemed to bear out the simple equation: control relevant insects and you control the disease.
These early successes were not easy to duplicate, however, and malariologists during the interwar period became polarised: those who believed that the control of malaria in an area would lead seamlessly to economic development, since a healthy population could transform a society; and those who held that the key to the malaria problem was economic prosperity in the first place. The latter group took the history of malaria in England as paradigmatic: “agues” and intermittent fevers had long been prevalent in marshy, badly drained areas of England, but had gradually disappeared from the 18th century, as England modernised. These two positions translate roughly to modern debates about vertical and horizontal malaria programmes, and although Packard clearly has more sympathy for the horizontal approach, he also reports modern studies that suggest that the dichotomy is not so simple. Indeed, Ross, generally a passionate advocate of vertical, insect-directed initiatives, also firmly believed that malaria eradication needed all effective approaches; both/and, not either/or, was his message.
Much of the subtle, ecologically and clinically sensitive knowledge so painfully gained during the interwar years was lost in the dichloro-diphenyl-trichloroethane (DDT) era. Packard allows himself one of the two iconic jokes of modern malariology, that DDT did not eliminate malaria, only malariologists. (The other story, not recounted here, is that Leonard Bruce-Chwatt, during one of the 1950s debates on DDT, suddenly folded his hands together, closed his eyes, and loudly intoned, “Let us spray.”) Almost half of Packard's book is devoted to this modern period, and he has much to say about the reasons why WHO's Global Malaria Eradication Programme, instituted in 1955, was abandoned in 1969. It was far too monodimensional, relied too much on DDT spraying, and neglected the palpable problem that the delivery infrastructure was not in place in too many parts of the malarious world. The emergence of widespread mosquito resistance to DDT, and parasite resistance to the cheap mainstay of therapy, chloroquine, compounded the difficulties. Excessive DDT use in agriculture was unfortunate, and its long-term environmental consequences concerned many. The programme also cost more than donor countries were prepared to countenance, or recipient countries could afford.
Packard is always dispassionate, never needlessly accusatory, but he also provides the evidence for the real mistake in the 1969 decision to pull the plug on the eradication programme. Although it had not achieved its goal in many parts of the world, it had achieved much. In the panic of abandonment, the international funding agencies forgot Ross's message: both/and. Instead of cutting off almost all malaria aid, the international community should have returned to the more diversified strategies of an earlier era. Despite all the difficulties in the late 1960s, and the problems since, the world was less malarious when WHO's eradication programme ended than when it began.
One must not put too optimistic a spin on contemporary malaria, and Packard offers some useful comparisons of the similarities and differences between the current Roll Back Malaria initiative and the eradication ambitions that preceded it a generation ago. Tellingly, Packard returns to the kind of analysis with which he began his book, in the traditional period of malaria. Focusing especially on Zambia, he shows how the same environmental and economic factors have coalesced to produce malaria in a country that was once the most prosperous in Africa. Packard argues that countries whose economies are based too intimately on one or two major industries (copper mining in Zambia) are especially vulnerable to fluctuations in international demand. Cotton production, for example, features in Packard's analysis of the contemporary malaria scene, an activity compounded by the US government's reversing fairtrade practice and subsidising its own cotton producers. Packard clearly believes that traditional socioeconomic understanding of malaria still has purchase. His is a sober message.
The Making of a Tropical Disease: A Short History of Malaria is a fine book. Its major weakness lies in the disappointing graphics. Clinical aspects of the disease are given short shrift, and few of the many larger-than-life personalities in malaria's history get their due. But this short book carries through its thoughtful approach with admirable power and consistency. Now that Bill and Melinda Gates have boldly put eradication back onto the malaria agenda, the lessons of the past acquire even more currency. Packard's book highlights how challenging the task will be.
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2808%2960612-1/fulltext