Not a simple problem after all

Abstract

World Class Parasites: Volume 1 The African Trypanosomesedited by Samuel J. Black and J. Richard Seed, Kluwer Academic Press, 2001. £80.74 (hbk) (192 pages) ISBN 0 79237 512 2The demise of the colonial system has not brought the birth of a new bright future for Africa. During the past several decades, Africa has suffered from anarchy, famine and tribal warfare. The public health system is in disarray and the region is plagued with epidemics, old and new. The diseases once thought to be under control are resurging. Sleeping sickness, caused by the subspecies of Trypanosoma brucei in sub-Saharan regions, is often overshadowed by AIDS and malaria. Nagana, a trypanosomiasis of cattle, is caused by related organisms and remains a serious impediment to economic development in Africa.The African Trypanosomes, written by renowned authors and edited by Samuel J. Black and J. Richard Seed, contains twelve chapters, which address the economic problems and describe approaches to control and prevent trypanosomiasis. This book represents the first volume of the new series World Class Parasites – intended to cover recent trends and advances in the research of parasites with a high impact on socioeconomics. The editors estimate that 300 000–500 000 people in Africa are affected by trypanosomiasis, which can be fatal if not treated. The situation is worse now than just a few decades ago and corresponds to the situation in the 1930s. The paradox is that, at the same time, in the developed world, more efforts and resources than ever are being devoted to finding rational ways to combat African trypanosomiasis.The book opens with a chapter written by David H. Molyneux, who gives his personal view on the failure of science and the public health system to prevent or stop the epidemics. This chapter is truly remarkable and the book deserves a reader's attention just for this alone. Molyneux noticed that trypanosome research had: ‘yielded an excess of scientific papers but no new drug’. However, science can still be ‘given a final opportunity to solve what ought to be a simple problem given the major differences between trypanosomes and mammalian cells’. Even though the simplicity thesis could be debatable, it is impossible to disagree with Molyneux on his main point: ‘an efficient use of the resources available today and a focus on the disease control would make a difference even in the absence of a magic bullet yet to be delivered by the drug design and vaccine development programs’.Accurate information is crucial for success because part of the solution proposed by Molyneux lies in the realm of rational decision-making. Chapters two and three describe the development of information systems to support the Program Against African Trypanosomiasis (PAAT), the predicted impact of climate and social factors on vector distribution, and the disease risk to year 2050. Both chapters would benefit from color maps instead of black and white ones. The following chapter is devoted to vector control and describes an innovative strategy to reduce disease transmission through replacement of trypanosome-susceptible tsetse with engineered trypanosome-refractory vectors. A reader with a practical mind would also be interested in an evaluation of more traditional strategies based on attractants and traps, but they have not been covered here. The diagnosis and chemotherapy chapters highlight the fact that the absence of effective diagnostic tests and drugs in the field mostly reflects the lack of incentives for the pharmaceutical industry to proceed with validation and production rather than the difficulties to develop these tools in the laboratory.Several chapters are devoted to trypanosome immunology and cell biology, including the new paradigm of host resistance, trypanotolerance mechanisms in some breeds of West African cattle, the discovery of a bloodstream trypanosome-released factor affecting cell division, and the endocytosis system. The trypanosome genome organization and the ongoing sequencing efforts are also covered, ending with a general discussion on the rational approaches to vaccine development.In the ideal world, the book would also include additional chapters on conventional vector control, mechanisms of human resistance to trypanosomes, and trypanosome metabolism and intracellular transport as mentioned by the editors as glaring omissions. But would there be African trypanosomes in the ideal world?