Malaria in the Solomon Islands

Book Reviews Malaria in the Solomon Islands edited by Akira Ishii, Naoko Nihei and Manabu Sasa, Inter Group Corporation, 1998. ¥3500 (viii 1 192 pages) ISBN 4 901070 00 2 Many researchers are working on malaria in a multidisciplinary pattern in different endemic countries. While individual reports on these activities are published in international journals, very few groups have produced a collective report in book format. This book provides a summary of such a multidisciplinary research programme carried out in the Solomon Islands between 1990 and 1995. It covers different areas of research, including diagnosis, pathophysiology, mosquitoes, epidemiology and control. Although a record of the first three years of the programme has already been published in Japanese, and some of the work described has been published in international journals, the present book is comprehensive and is accessible to a wider readership. It is laid out in a format of related papers in five chapters. Each chapter includes reports of activities in one discipline; however, some sections contain overlapping data, which makes the book repetitive. Diagnosis of the parasite remains one of the major challenges to malaria control and management. A discussion on the sensitivity and specificity of methods for malaria diagnosis includes conventional microscopy, fluorescence microscopy, PCR, as well as enzymatic and microplate hybridization for detection of PCR products. Other studies evaluate clinical diagnosis of malaria (based on clinical symptoms), a widely used method throughout the tropics at primary health care units, and the use of portable ultrasound for detection of splenomegaly. Portable ultrasound, a new approach for malaria surveys, showed encouraging results. The chapter provides useful information for clinical practitioners and health administrators. However, one point not mentioned is that the indiscriminate use of antimalarials, as a result of falsepositive diagnosis, may lead to increasing drug pressure and then to evolution of drug resistance. In my view, the urge for a prompt diagnosis of malaria in the tropics should not compromise measures to apply antimalarials in ways to minimize the risk of resistance developing.

Research on pathophysiology is covered in a very interesting chapter, the bulk of it comprising studies on malaria-related genetic polymorphisms, including haemoglobinopathies, G6PD deficiency and polymorphism of TNF-a. The polymorphism of the TNF-a promoter was considered as a possible correlate of severe malaria risk in Guadalcanal island. Compared to an African situation, a general lack of TNF-2 allele was observed in Guadalcanal. The authors argue that the absence of the TNF-2 allele is relevant to the rarity of severe and cerebral malaria in the island. This chapter also outlines two interesting immunological studies: the first discusses epitope mapping of the Plasmodium falciparum major merozoite surface glycoprotein, MSP-1. The authors obtained evidence for distinct homing into different blocks of the N-terminal region of MSP-1 by blastoid T-cell lines from exposed islanders and non-exposed donors. This difference in recognition is not dictated by HLA-class II alleles, as it was observed in populations sharing the same HLA-DR specificity. The second study characterized a neutrophil chemotactic factor (PyNCF) of the rodent malaria parasite Plasmodium yoelii, and demonstrated crossreactivity with the corresponding P. falciparum protein on the basis of its sera recognition. A discussion follows on the relevance of this chemotactic factor to the early inflammatory responses during malaria. The chapter on mosquitoes and vectortargeted control measures contributes to the current debate, raised in Parasitology Today, on the possible impact of control measures on malaria morbidity and mortality. In agreement with studies carried out in various endemic countries, the impregnated bednets have shown a better impact on malaria than residual spraying. The main mosquito vector, Anopheles farauti, bites people mostly during the early evening. Studies have thus evaluated the use of inexpensive mosquito repellents used at this time of the day, such as a smoking mosquito candle. Interestingly,

these inexpensive methods exhibited inhibition of mosquito biting as effective as that provided by permethrin-impregnated bednets. These findings urge for application of such affordable methods in areas with vectors of similar feeding behaviour. However, the authors have concluded that impregnated bednets are in fact better, because they increase mosquito mortality and reduce its vectorial capacity. The last chapter comprises four papers discussing the epidemiology and counter measures against malaria in the Solomon Islands. An interesting study investigated human ecology in relation to malaria, and highlighted some behavioural habits related to mosquito bites. For example, the social activities of the inhabitants in the early evening, the most risky time, were related to apparently poor effects of bednets. This was emphasized by a stimulating malaria transmission model, which accounts for compliance with protective behaviour against mosquito bites. A different malaria transmission model was used, in another study, to compare malaria levels in the Solomon Islands and Vanuatu and to assess the impact of control measures. While the conclusions were of interest, details of the model, unfortunately, are not given. The data content and quality are well balanced, and the research teams involved clearly made a good interdisciplinary approach to malaria research. My main concern is that some of the papers are presented in a rather loose format, and the conclusions drawn may need more data and analysis. Some of the figures and tables are very small, and their details are difficult to read. At the end of the book, all published literature on malaria in the Solomon Islands from 1950 to 1997 has been put together. This section thus gives the book great value in being a good reference to all work on malaria in this country. In addition to its scientific content, the book provides useful background information on the Solomon Islands, aided by very clear maps. Undoubtedly, this book would interest researchers and health professionals. Hamza Babiker Institute of Cell, Animal and Population Biology University of Edinburgh West Mains Road Edinburgh, UK EH9 3JT

Coming soon in Parasitology Today • Parasitic nematodes, proteinases and transgenic plants, by C.J. Lilley, P. Devlin, P.E. Urwin and H.J. Atkinson • Enzymes of pasasite thiol metabolism as drug targets, by R.L. Krauth-Siegel and G.H. Coombs • Cytokines, nitric oxide, heat-shock proteins and virulence in Toxoplasma gondii, by C.M.D. Miller, N.C. Smith and A.M. Johnson • The molecular evolution of trypanosomes, by J.R. Stevens and W. Gibson • Can Babesia infections be used as a model for cerebral malaria? by T.P.M. Schetters and W.M.C. Eling • Signal transduction pathways in Entamoeba histolytica, by I. Meza • The targets of the lytic response against Trypanosoma cruzi, by G.M. Krautz, J.C. Kissinger and A.U. Krettli Don’t miss out on these and many other articles of interest in this highly cited journal; make sure you have your own subscription to Parasitology Today, using the form bound in this issue. Parasitology Today, vol. 15, no. 8, 1999

0169-4758/99/$ – see front matter © 1999 Elsevier Science. All rights reserved.

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