The total number of drug users in Pakistan remains unknown. The National Survey on Drug Abuse in Pakistan in 1993 estimated 2.7 million users of narcotics and psychotropic substances in a total population of 125 million. Heroin, the most prevalent drug of abuse was used by 1.52 million. In this survey injection drug use was first reported in 1.8% addicts in Karachi, a center of commerce, the chief seaport and the largest city of the country with a population of over 10 million . Recent estimates indicate 5 million drug users in Pakistan . Personal communications with field workers, researchers and donors suggest that there is an increasing shift towards injection drug use (IDU) among addicts. Possible reasons for this preference for injection could be the change in heroin quality. The currently available product cannot be inhaled because its impact on lungs is quite severe and has caused respiratory distress in some cases. (Personal Communication, Irshad Khan & Joe Augustine, 2006). There is also limited availability of inhalation quality heroin, and there is a rising cost of other psychotropics . Before the Afghan war the proportion of inhalation addicts was much higher than today and the inhalation material was called "brown sugar" which was heroin however since 2001 "brown sugar" is not available in Karachi and the most common material largely available and used by addicts is called "white stuff" and it can only be injected. (Personal Communication, Irshad Khan & Joe Augustine, 2006).
A study publishing data from Karachi in 1995 reported 25% of a mixed population drug users using injectable drugs and of these 52%, sharing needles. None of the users were tested positive for HIV in that study . However in a different study in Karachi in 1996 out of 242 IDUs, one was HIV positive . In a similar study of IDUs in 2002 no one tested positive for HIV .
Global pattern of HIV indicates that injecting drug use has provided a "kick start" to the epidemic .
Pakistan has been considered a low prevalence "nascent epidemic" for HIV/AIDS transmission. However, surveillance data from Sindh (Provincial) AIDS Control Programme suggest that Pakistan may already have progressed from low to concentrated level of HIV epidemic since 2003, when 19 IDUs were confirmed HIV positive in Larkana, a small town in the Sindh Province. This was the first such outbreak reported from Pakistan .
Present study was conducted in 2003 to assess high risk behaviors and prevalence of HIV, hepatitis B and C and syphilis among registered IDUs of a Needle Exchange Programme developed by Marie Adelaide Rehabilitation Programme. This center was established with support of United Nations Office for Drug Control and Crime Prevention (UNODC) and Joint United Nations Programme on HIV/AIDS (UNAIDS) in 2002. In this research correlates to HIV, HCV, HBV and syphilis were studied.