This book describes the overall situation of HIV transmission in South Asian countries and the implementation status of 'harm reduction'' programmes. The adult prevalence of HIV is below 1% in South Asia although high prevalence is observed mainly among IDUs. The prevalence of HIV is relatively higher in India and Nepal compared to other countries in South Asia. Low prevalence is observed in Muslim nations in spite of widely prevalent high risk taking behaviours. Information about 'harm reduction'' programmes are available from four countries but the issue of effectiveness is still not adequately addressed. The role of education, migration and religion in the spread of HIV and the issues of effectiveness of 'harm reduction'' programme in South Asia is discussed in this book. A low coverage of 'harm reduction'' programmes has made it difficult to see an overall impact related to HIV burden among IDUs. This book provides an excellent opportunity to researchers and professionals seeking quick understanding of the scenario of HIV and IDU in South Asia.