prevalence among IDUs should be interpreted with caution (Aceijas et al., 2004).
Based on these data, the UN Reference Group estimated that there are 13.2 million injecting drug users worldwide (Aceijas et al., 2004). Of those, an estimated 8.8 million live in Eastern Europe and Central, South, and Southeast Asia (Aceijas et al., 2004; UNAIDS, 2006), and an estimated 10.3 million (or 78 percent) live in developing or transitional countries (see Figure 1.1). A major driver of the rapid expansion of HIV in these and other areas is injecting drug use, accounting for about one-third of new infections outside sub-Saharan Africa. Worldwide, an estimated 10 percent of all HIV infections are related to injecting drug use, although that proportion is estimated to be much higher in certain regions of the world (UNODC, 2005; WHO, 2005a; Aceijas et al., 2004).
Primarily because of injecting drug use, Eastern Europe, Central Asia, and the Commonwealth of Independent States have witnessed as much as a 20-fold increase in the number of people living with HIV in less than a decade (UNAIDS, 2006). The majority of these individuals live in Ukraine and the Russian Federation. In Russia, an estimated 940,000 people were living with HIV at the end of 2005, and unsafe injecting practices are the main cause of HIV infection among people under the age of 30 (UNAIDS, 2006). In Ukraine, unsafe injecting practices and unprotected sex are both responsible for alarming increases in HIV infection. In some cities in Ukraine, 58 percent of IDUs are HIV-seropositive (UNAIDS, 2006). Young people are especially affected by the increase in HIV transmission among IDUs in the Commonwealth of Independent States, as many IDUs are below the age of 25 and began injecting before the age of 20 (UNAIDS, 2005).
Many other countries in Eastern Europe, Central Asia, and the Commonwealth of Independent States are also experiencing growing HIV epidemics. Currently, injecting drug use fuels the HIV epidemic in Uzbekistan, Kazakhstan, and Armenia (UNAIDS, 2006). Tajikistan is witnessing a smaller, yet rapidly evolving epidemic, illustrated by a study in its capital Dushanbe, which found an HIV prevalence of 12 percent among IDUs (Stachowiak et al., 2006). Sexual transmission continues to drive the epidemics of countries such as Belarus, Azerbaijan, Georgia, and Romania. However, both the continued increase in the number of injecting drug users and the rising HIV prevalence rates among both injecting drug users and sex workers could signal that a more generalized epidemic is looming (UNAIDS, 2006).
In Asia, an estimated 8.3 million people were living with HIV at the end of 2005, with India home to more than two-thirds of these individuals (UNAIDS, 2006). While sexual transmission is still the predominant route of transmission in India, injecting drug use is driving the epidemic in the