1. Introduction
Many incurable diseases in the world are being cured and eliminated with the development of science and technology, while there are some new adverse factors probably can result in great harm to people 's health. Amongst these factors, the use of illicit drug is a crucial cause of spreading infectious diseases and deaths. It is estimated that more than 200 million people use illicit drugs in 2010 and among these user, approximately 100,000 deaths are related to the use of illicit substance (United Nations Office on Drugs and Crime, 2012). Furthermore, illicit drug use also indirectly hinders the development of economy and society, for instance, it accounts for the productivity losses, heavy financial burden, increasing criminals, and damaged environment (The Nossal Institute for Global Health, 2010). Under these unhealthy and unstable situations, the health problems caused by the use of illicit drugs are expanding rapidly and severely. The risk of illicit drug use impairs human body, undermines economic development and damage social stability.
2. Impact on health
The use of illicit drug causes global health issue that it brings about numerous fatal diseases including inducing stroke, lethal arrhythmias and hyperthermia, particularly blood borne. Drug use, especially injected drug use (IDU), is a crucial vector for spreading blood borne such as HIV and Hepatitis B and C. IDU induces high danger of spreading of HIV; as a result, IDU is responsible for approximately ten per cent of all HIV patients worldwide. Another relevant statistic of IDU is that amongst 16 million IDUs globally, about one in five is HIV-positive (United Nations Office on Drugs and Crime, 2012). Furthermore, the distribution of AIDS related to IDU in some parts of the world is considerable different, for instance, 50-90% HIV infections in central and eastern Asia, Eastern Europe and the Pacific are blamed on