HIV and people who use drugs in central Asia: confronting the perfect storm.

Despite substantial advances in reducing HIV incidence and expanding access to antiretroviral therapy (ART), Central Asia (CA) lags behind gains made in other countries (Joint United Nations Programme on HIV/AIDS, 2012a,b,c,d). While HIV incidence is decreasing globally, the number of new HIV infections in CA is rising among people who inject drugs (PWID), female sex partners of PWID, men who have sex with men (MSM), female sex workers (FSW), and migrant workers (Joint United Nations Programme on HIV/AIDS, 2012a,b,c,d; Donoghoe, 2012; Jolley et al., 2012; Thorne et al., 2010). In several CA countries (i.e., Kazakhstan, Kyrgyzstan, Uzbekistan, Tajikistan, Turkmenistan), an estimated 1% of adults inject drugs, but the number exceeds 10% in areas along major drug trafficking routes, representing one of the highest rates of injection drug use in the world (Joint United Nations Programme on HIV/AIDS, 2012a,b,c). More than half of recently-diagnosed HIV infections in the region are estimated to occur in the PWID population (Joint United Nations Programme on HIV/AIDS, 2012a,b,c). Furthermore, the prevalence of hepatitis C virus (HCV) infection is exceptionally high among PWID in these countries (Beyrer et al., 2009; Walsh and Maher, 2012; El-Bassel et al., 2013), and the rates of multidrug-resistant tuberculosis (MDR-TB) in PWID in CA are also among the highest in the world (World Health Organization, 2012). Recent evidence suggests that PWID in CA are increasingly using heroin synthetic substitutes and mixing different drugs and alcohol, which may further increase their risk for morbidity and mortality from HIV, HCV, TB, and overdose. Some forms of non-injection substance use, particularly amphetamine-type stimulants and other drugs such as “krokodil” (a home-made drug) have increased in CA (Grund et al., 2013). Excessive alcohol use in the region is associated with decreased utilization of health services, poor adherence to ART (Mellins et al., 2009), and engagement in risky drug-related and sexual behaviors among PWID (Wolfe et al., 2010; Abdala et al., 2010). Excessive alcohol intake among individuals receiving ART is also associated with a decreased likelihood of them having an undetectable HIV viral load (Gonzalez et al., 2013). The relationship between non-injection drug use and HIV acquisition among PWID in the region remains poorly understood. Despite evidence suggesting widespread drug use (injection and non-injection) and the rising incidence of HIV among PWID in CA, region-specific research and scientific publications remain limited on the epidemiology of HIV and its co-morbidities, as well as HIV prevention and treatment among PWID. In this supplement of Drug and Alcohol Dependence, authors from diverse disciplinary backgrounds and differing scientific expertise seek to address these large gaps in the scientific literature. This supplement is designed to deepen understanding of the HIV epidemic’s scope, the scope of related co-morbidities such HCV and TB in CA, and the status of harm reduction and other HIV-related services. Given recent advances in biomedical HIV treatment and bio-behavioral prevention, this supplement highlights the need for implementing such interventions in the region and emphasizes the importance of promoting prevention and health care for PWID in CA. Each of the articles in this supplement describes available information on a specific issue, identifies gaps in scientific knowledge, and provides an agenda for future research endeavors. Although this supplement issue focuses mainly on the five countries traditionally considered to constitute the Central Asia region (Kazakhstan, Kyrgyzstan, Uzbekistan, Tajikistan, Turkmenistan), a number of the included papers provide information on relevant issues from adjacent countries with similar epidemics, countries such as Afghanistan, Mongolia, and China. 1.1. Structure of the supplement The first section of this supplement focuses on the epidemiology of HIV and the overlapping co-morbidities of HCV and TB, and describes risk environments that increase the risk of HIV among key populations in CA: PWID, MSM, female sex workers, and migrant workers. The second section focuses on the scope of harm reduction programs in CA, including policies and socio-structural barriers that prevent PWID from accessing and utilizing such programs. This section also addresses overdose prevention and access to naloxone. The third section focuses on the status of HIV testing and HIV care and treatment, and discusses coverage of biomedical prevention among PWID in this region.