High risk behaviors of injection drug users registered with harm reduction programme in Karachi, Pakistan.

Background: Surveillance data of Sindh AIDS Control Programme, Pakistan suggest that HIV infection is rapidly increasing among IDUs in Karachi and has reached 9% in 2004-5 indicating that the country has progressed from nascent to concentrated level of HIV epidemic. Findings of 2nd generation surveillance in 2004-5 also indicate 104/395 (26.3%) IDUs HIV positive in the city.