Gender disparities in HIV infection among persons who inject drugs in Central Asia: A systematic review and meta-analysis

Abstract

Objective

Disparities in HIV infection, with females having higher rates of HIV infection than males, have been noted among persons who inject drugs (PWID) in many countries. We examined male/female HIV disparities among PWID in Central Asia and compared these disparities with patterns worldwide.

Methods

A systematic review and meta-analyses were conducted for studies reporting HIV prevalence by gender among PWID. To be included in the analyses, reports had to contain (1) samples of PWID from Central Asia, (2) HIV data based on laboratory testing, (3) HIV prevalence reported for males and females, and (4) samples that were not recruited on the basis of HIV status.

Results

Data were abstracted from 11 studies in 5 countries in Central Asia: China, Kazakhstan, Russia, Tajikistan, and Uzbekistan; the total sample size was 12,225. The mean weighted OR for HIV prevalence among females to males was 0.913 (95% CI 0.07, 1.26), with high heterogeneity among studies (I² = 70.0%) and a possible publication bias among studies with small sample sizes (Eggers test = −1.81, 95% CI −5.18, 0.54).

Conclusions

The non-significant higher HIV prevalence among male PWID in Central Asia contrasts with the worldwide findings which show slightly higher HIV prevalence among female PWID. This may reflect the relative recency of the HIV epidemics in Central Asia. The findings also suggest there may be factors that protect female PWID from HIV in some settings. Further examination of transmission dynamics in Central Asia is necessary to better understand the HIV epidemic among PWID.

Introduction

Persons who inject drugs (PWID) are at high risk for infection with human immunodeficiency virus (HIV); however, not all persons who inject drugs are at equal risk for becoming infected with the virus. There are multiple reasons why females who inject drugs may be at higher risk for becoming infected with HIV than males who inject drugs. Females may have greater difficulties in obtaining sterile injection equipment (Parker and Aggleton, 2003). Females may experience greater discrimination when they seek treatment for substance use disorders (Khalid, 2007, UNODC, 2012). Female PWID are quite likely to have male PWID as sexual partners while male PWID are likely to have females who do not inject drugs as their primary sexual partners (Go et al., 2006). Male to female sexual transmission of HIV is more efficient than female to male transmission (European Study Group on Heterosexual Transmission of HIV, 1992), so that female PWID are likely to be at higher risk for acquiring HIV through sexual transmission. There is a moderate overlap of females who are commercial sex workers and also inject drugs in certain countries, including China (Gu et al., 2009, Wang et al., 2012), Mexico (Ulibarri et al., 2010) and Russia (Decker et al., 2012, Kozlov et al., 2006), facilitating both injection related and sexual transmission of HIV. Finally, there are substantial gender inequalities in many countries (including Central Asian countries) (United Nations Development Program, 2012) that may contribute to higher HIV risk for females in general.

Many countries in Central Asia are currently experiencing injecting drug use concentrated epidemics (Mathers et al., 2008). In this report, we examine the evidence for sex disparities in HIV among PWID in countries in Central Asia, compare these disparities with sex disparities among PWID in other parts of the world, and consider the implications for the prevention and treatment of HIV among PWID in Central Asia.