POSTER PRESENTATIONS 261

with 90 min (includes 60 min for fixing) using modified Trichrome; and (iv) most clinical laboratories in devel- oping countries have Field's stain (used to stain blood films for malarial and filarial parasites). Modified Field's stain offers a rapid, reliable, and inexpensive alternative for the microscopical identification of intest- inal microsporidian spores.

Pre l iminary results o f a s tudy into the inc idence o f cryptosporidios is in paediatr ic pat ients in rural and urban areas o f Malawi

T. D. T h o m s o n ~, A. M. Gr imason ~, K. C. T e m b o 2, Z. Banda e, R. Mwenda 3 and P. Chapepa 2 1Divi- sion of Environmental Health, Department of Civil Engi- neering, University of Strathclyde, Glasgow G40NG, UK; 2Dep.artment of Environmental Health, Polytechnic, Uni- verszty of Malawi, P.B. 303, Blantyre, Malawi; 3Laboratory Department, Queen Elizabeth Central Hospi- tal, Blantyre, Malawi

Two hospital-based studies are currently under way in Blantyre (urban) and Chikwawa (rural) districts, Malawi, to determine the incidence of cryptosporidiosis in children aged < 5 years presenting with symptoms of diarrhoea. To date, stool samples have been collected over a period of 7 months (February-August 2001) constituting the rainy and dry seasons. Stools were examined for the presence of Cryptosporidium oocysts using the modified Ziehl-Neelsen technique and an immunofluorescence antibody technique. Of 279 sam- ples examined from both paediatric wards and out- patient clinics (Blantyre, n = 218; Chikwawa, n = 61), 13 (4.6%) were found to contain oocysts (9 Blantyre [4.1%]; 4 Chikwawa [6.6%]). The number of oocysts per field of view (magnification × 400) ranged from +1 to +4. The majority of cases were in children aged < 12 months (62%), with a number of these suffering persistent diarrhoea. These findings are similar to those reported in studies undertaken in other sub-Saharan African countries.

Book Review ] Malaria Control D u r i n g Mass Popula t ion Move- m e n t s and Natural Disasters . Peter B. Bloland & Holly A. Williams. Roundtable on the Demography of Forced Migration Committee on Population, National Research Council. Washington DC: The National Aca- demies Press, 2003. xvi + 164 pp. Price £26.95 (paper- back). ISBN 0-309-08615-9.

Malaria is often a major health problem among populations affected by conflict or natural disasters in the tropics. In war-torn countries especially, breakdown of health services, forced migration and resettlement of vulnerable (often non-immune) refugees to areas prone to epidemics, environmental deterioration, and in- creased human-vector contact may all contribute to abnormally high malaria burdens, and it is estimated that up to one-third of malaria deaths occur in such countries. It is increasingly recognized that malaria control in emergencies requires special measures or alternative approaches to the practices used in stable situations, and UN and non-governmental organiza- tions (NGOs) involved in health delivery in emergen- cies are crying out for guidance. This monograph by Peter Bloland and Holly Williams is a significant at- tempt to address this need, and builds on the recom- mendations of the Roll Back Malaria (RBM) 'Outline Strategy for Malaria Control in Complex Emergencies' developed by an RBM Technical Support Network, of which Williams and Bloland are members. It provides a broad overview of the present state of knowledge in emergencies, and covers the most important elements including surveillance, epidemiology, diagnosis and case management, prevention, social behaviour and community involvement, and post-emergency malaria control. It sensibly draws on knowledge generated in stable countries, where relevant, as the literature ema- nating from emergencies is still rather fragmentary.

Their declared target audience are the health care practitioners who provide service to refugees and dis- placed populations, but the book can be recommended as a good introductory text for anyone who is interested in the practice of malaria control whether in stable or conflict-affected countries. The sections on diagnosis, chemotherapy, and case management are particularly thorough, as might be expected from these authors, and they also make a robust argument for conducting operational research during emergencies as and when necessary. The section on prevention through use of insecticide-treated nets and other forms of vector con- trol is less detailed, and anyone wanting advice on how to implement such interventions would be dis- appointed. More novel approaches to prevention, only touched on here, such as insecticide-impregnated plas- tic shelters and repellent blankets, are fast coming on stream and show great promise for the initial, acute phase of emergencies, when mortality rates are highest and conventional approaches are inadequate for the task. Repellent soap is another cost-effective interim measure, but the authors make the common error of assuming this type of product is used like soap for washing. Their position on the use of combination- therapy during emergencies is one of caution, and they express the need for further evidence, which will not please emergency NGOs such as MSF who strongly advocate the global adoption of combination-therapy for malaria treatment following the disastrous experi- ence resulting from the use of chloroquine and sulfadoxine-pyrimethamine during the epidemic in Burundi 2 years ago. Overall though, this is a level headed and thorough review which paves the way for RBM's long awaited Handbook for Malaria Control in Emergencies, due to be published later in 2003.

Mark Rowland Disease Control and Vector Biology Unit London School of Hygiene and Tropical Medicine Keppel Street, London WCIE 7HT, UK