A publication of the Area on Emergency Preparedness and Disaster Relief of the Pan American Health Organization, the World Health Organization, and the International Committee of the Red Cross. The views expressed, the recommendations made, and the terms employed in this publication do not necessarily reflect the current criteria or policies of PAHO/WHO or of its Member States. The Pan American Health Organization welcomes requests for permission to reproduce or translate, in part or in full, this publication. Applications and inquiries should be addressed to the Area on Emergency Preparedness and Disaster Relief, Pan American Health Organization, 525 Twenty-third Street, N.W., Washington, D.C. 20037, USA; fax: (202) 775-4578; e-mail: disaster-publications@paho.org. This publication has been made possible through the financial support of the Division of Humanitarian Assistance, Peace and Security of the Canadian International Development Agency (HAPS/CIDA), the Office of Foreign Disaster Assistance of the United States Agency for International Development (OFDA/USAID), the United Kingdom’s Department for International Development (DFID) and the European Commission Humanitarian Aid Office (ECHO).