"Prevalence of hepatitis C virus (HCV) and of syphilis among IDUs can indicate the extent of risky injecting and sexual behaviours respectively. HCV prevalence among IDUs exceeds 60% in Tajikistan and Uzbekistan and 70% in parts of Kazakhstan, and up to one in six IDUs have syphilis (table 3).31,55,58 Female IDUs are particularly vulnerable to infection with HIV, HCV, and STIs, because of the exchange of sex for drugs or money and risky injecting behaviours:52,59 28% of female IDUs in a study in Dushanbe, Tajikistan, had syphilis (75% of whom reported transactional sex) compared with 13% of men,55 and in a study in Kazakhstan, female IDUs were 2·3-times more likely to be HIV positive than men and had a syphilis prevalence of 11% compared with 5% among male IDUs.37 The estimated 20–24% of male IDUs who have sex with female sex workers also underscores how these risk groups intersect.32,47,56,57"
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
