"The rapid spread of HIV among IDUs in central Asia has been aided by high prevalence of risky behaviours; 50–70% of IDUs share injecting equipment, purchase pre-filled syringes, or draw-up from common containers, and the use of condoms is low (table 4).6,32,34,52–55 Specific drug preparation practices might also increase risk, with blood used in the preparation of so-called vtoryak, a solution obtained by reprocessing materials after preparation of khanka; however, vtoryak was used by less than half of IDUs in a 2002 study in Kazakhstan.37 Studies have shown average durations of injecting of 3–9 years among IDUs, the average age of whom is decreasing.34,55–57 In Tajikistan, recent initiates were twice as likely to be HIV infected than those with longer injecting histories, suggesting riskier behaviours46 and potentially less use of harm reduction services than older, more established IDUs."

Source

Claire Thorne, et al., "Central Asia: Hotspot in the Worldwide HIV Epidemic," The Lancet Infectious Diseases, 2010 Jul;10(7):479-88. doi: 10.1016/S1473-3099(10)70118-3