Pakistan is one of the countries hardest hit by narcotics abuse in the world. According to national drug abuse surveys, the number of chronic abusers of heroin increased from about 20,000 in 1980 to more than 1.5 million in the late 1990's.
Drugs in the region are mostly ingested orally; heroin is usually smoked or the smoke is inhaled. In Pakistan, a small number of heroin injection cases have begun to emerge in the Karachi area. This practice -- previously unknown in the subregion -- has been observed in recent studies and raises concerns about the increase risk of transmitting blood-borne diseases, such as hepatitis and HIV/AIDS, through the process of needle sharing