According to a WHO study, worldwide about 3 % of people use narcotics, of whom about 60 % do so intravenously, for a total of about 72 million IDUs. About 12 % of these will contract AIDS at some point.
根據 WHO 的研究，全世界約有 3 % 的人使用毒品，其中靜脈注射毒品者占 60 %，約 7200 萬人，這些人中約有 12 % 會染上愛滋。