Georgia is categorized as a low-HIV-prevalence country [3]. The estimated prevalence among the adult population is 0.1% [1]. According to the national HIV registry data, there has been a sharp increase in newly diagnosed cases since 2004, with a steady increase since 2008. Annually, almost half of the newly diagnosed cases are revealed at the AIDS stage of disease. There is regional heterogeneity in HIV prevalence with higher rates in the capital (Tbilisi), regions bordering Turkey, and in the conflict zone of Abkhazia [3]. Injection drug use remains a major risk factor for HIV transmission. In 2009, more than 70% of new HIV infections were attributed to injection drug use or sexual contact with an injection drug user [2].

Drug abuse and its related health and social consequences are critical challenges facing Georgia. As a bridge between Europe and Asia, Georgia and other south Caucasian countries serve as a drug trafficking route into Russia and Europe. The conflict regions may also have conditions that support drug trafficking. No reliable estimates on the extent of drug use in Georgia currently exist [4].

The study inclusion criteria were as follows: aged 18 years or older; drug injection in the month prior to the survey; and being a resident of the selected survey location. The interviews were conducted at fixed sites located in the centre of each city by trained interviewers from the local non-governmental organization, "Bemoni," which has extensive experience working with IDUs.

Those who were eligible to participate in the study went through the informed consent procedure. In a private area, the participant was informed about the study, and if willing to participate, he/she signed a consent form. Following consent, the survey was conducted and participants were asked to voluntarily provide a blood sample for HIV testing. Tests were anonymously linked to the participants. The Genscreen^® Ultra HIV rapid test was used for HIV screening. HIV-positive samples were tested with a Western Blot (HIV Blot 2.2, Genelabs Diagnostics) confirmatory test. Respondents were asked to come with their identification card to receive their results. Post-test counselling was provided on site, and respondents testing positive for HIV were referred to a designated centre, where free treatment services were available.

The study protocol and questionnaires were approved by the Ethics Review Committee of the HIV/AIDS Patients Support Association, Georgia. Overall, 1127 eligible IDUs, including seeds, participated in the Bio-BSS studies in Tbilisi, Batumi, Zugdidi, Telavi and Gori.

Univariate and multivariate logistic regressions were used to evaluate predictors of HIV prevalence. Analyses were done for the combined samples from all five study locations.

It is interesting to note that the HIV prevalence, while low, is increasing in Georgia [2], and the highest prevalence of HIV was noted in a major urban area (Tbilisi) and/or geographically near the border of the country (Batumi). Previous Bio-BSS among IDUs carried out in these locations in 2004 revealed an HIV prevalence of 0.4% in Tbilisi and 2.1% in Batumi [13,14]. Comparison with our study findings demonstrates increases in HIV prevalence in both locations, with a statistically significant change for Tbilisi IDUs (p < 0.05). This may be important for the identification of potential entry points for HIV prevention programming.

No association was found between high-risk injection behaviour at last injection (use of shared syringe, use of potentially contaminated syringe, and joint use of injecting paraphernalia) and HIV positivity. It is not likely that IDUs underreport engagement in unsafe injecting practices as there is general consensus that IDUs do reliably report such behaviours in studies of this type [15]. However, we measured injecting behaviour at last injection, which may substantially differ from behaviour during previous injections.

The alarmingly high prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) among IDUs in Georgia is an indicator of unsafe injecting practice, which IDUs may have engaged in during their injecting career. In all, 64.6% of IDUs tested in Tbilisi in 2006 were infected with HCV [13]. In a 2000-01 study, a prevalence of 55.2% of HBV-positive cases was identified [16]. This corresponds to the finding of our study that 59.1% of IDUs have ever used a shared syringe. It is notable that a comparison of syringe sharing at last injection with the 2002-04 Bio-BSS results showed a reduction in this behaviour among Tbilisi and Batumi IDUs, with a statistically significant reduction among the Tbilisi sample (from 15.3% in 2002 to 3.4% in 2009, p < 0.05) [13,14]. Prevalence of other risk factors, such as joint use of injecting paraphernalia remains high (46.4%).

The multivariate analysis revealed duration of injection as the major predictor of HIV risk. This finding is not surprising since as the duration of injection drug use increases, clearly the risk of HIV increases by repeated exposure and via potentially unsafe drug practices.

As a predictor of HIV exposure, a history of imprisonment or detainment also raises important issues for the prevention of HIV in Georgia. It is well documented that imprisonment, which is common among IDUs, is associated with elevated HIV risk. Studies indicate that there have been prison-based HIV outbreaks in Russia, Lithuania [17,18] and many other countries [19-21]. While drug injection frequency may decrease in the prisons, there is a greater risk of syringe sharing among imprisoned individuals due to restricted syringe availability. Syringe-exchange programmes within prisons are highly controversial, although some European countries [22], as well as Moldova, Belarus and Kyrgyzstan among former Soviet Union countries, have introduced such programmes in their prisons. Among other preventive schemes, drug-substitution therapy has proven its effectiveness in HIV risk reduction. Regrettably, such services are only now starting to become available in Georgian prisons, and only in pre-detention facilities. While there are often political barriers to the implementation of harm-reduction interventions in correctional institutional settings, this analysis identifies a potentially vulnerable sub-population towards whom interventions should be directed.

Although coverage of IDUs by comprehensive preventive programmes was low, the programmes had reached their clients through various discrete interventions. In this study, close to 100% of participants had been exposed to HIV prevention information. The IDUs, regardless of their HIV status, were also well informed about the modes of HIV transmission. Satisfactory knowledge, combined with easy access to disposable syringes from pharmacies, could be an explanation of relatively low syringe sharing as the riskiest behaviour in HIV transmission, thus contributing to low HIV prevalence among IDUs so far.

There are, however, factors at micro- and macro-environmental levels that confer risk for HIV infection [23]. At micro-environmental level, the study shows low HIV testing uptake among IDUs. This corresponds to the national HIV statistics data that a significant proportion of cases are identified at a late stage, when AIDS has already developed. This is especially concerning given very low condom use among IDUs with their regular sexual partners. At the macro level, proximity to drug trafficking and distribution routes and exposure to war are known to influence risk of HIV acquisition [23].

Both factors exist in Georgia, as the country is situated on the Silk Route (or North Route) of opiate trafficking from Afghanistan, and there are unresolved conflict areas in the northern parts of Georgia. According to the World Drug Report, opiate seizures have been declining through the Silk Route [24], but at the same time, the Georgian Internal Services reports a substantial increase of illegal smuggling of buprenorphine from European countries [4]. All of this re-emphasizes the need for structural HIV prevention interventions.

The prevention of HIV transmission in this sub-population, therefore, may lie in strengthening behaviour-modification and harm-reduction programmes, including interventions to increase HIV testing, rather than through education and informational programming. A follow-up analysis is being conducted to review the matching of this knowledge with risk behaviours in this population.