In the large sample of PWIDs recruited from NSP and PDI, we found similarities in injection-related risk behaviour, while the sexual risk behaviour was different. These differences appear to be driven by the gender of PDI participants, as shown through the large deviation in risk scores across gender in the NSP and PDI group in Risk Assessment Battery. These findings suggest that PDI-type interventions may benefit from the incorporation of interventions directed to safe sex practice promotion, and that potentially, NSP participants could benefit more than PDI participants in further education.
PDI recruited young injectors and PWIDs with poor HIV testing practice, as shown by the large proportion of young PWIDs recruited by PDI compared to NSP and their lack of HIV knowledge during knowledge testing, the differences between which were statistically significant. Successful PDI in other locations has been shown to be effective in recruiting young PWIDs, who were much less likely to have ever been tested for HIV . Other studies have analysed the efficacy of PDIs, including in the context of Russia, and have found them to be able to reduce injection frequency, reducing sharing of syringes and equipment, and reduce rates of unprotected sex . The effect that recruitment of previously unknown, high-risk individuals could have on the PWID community is noteworthy and its successes in recruiting hidden populations, including in our context, is cause for wider evidence gathering and implementation.
PDI was successful in finding PWIDs who, for whatever reason, were not known to harm reduction services, even though such services had been established for years. Similar successes with previously under-represented populations have been documented with other PDIs, such as in Ukraine, where PDI managed to attract more young and female PWIDs who had not previously used a harm reduction service . Many potential reasons have been cited as barriers to access to harm reduction activities and disease treatment in other locations, including lengthy waiting times , expense of private treatment , work schedules , lack of social marketing , unawareness of services , previously negative test results creating complacency , lack of female-oriented services , and even just stagnation of service efficacy due to its age . It is unsure why these populations had remained unknown to harm reduction services in our sample, and acknowledgement of these previous findings and the limitation of efficacy that they can produce should be further investigated in the context of individual harm minimisation programs, such as in Georgia.
According to our study’s findings, participants of NSP were engaged in lower levels of syringe sharing, had comparatively better knowledge on HIV, and had higher HIV testing uptake, all of which were statistically significant differences between NSP and PDI groups. The link between clean needle programs and reduction in drug risk has been noted in other studies . This is a welcome finding that underscores the benefits of participation in NSP, as lower levels of testing and education confer greater risk to PWIDs, their partners, families, and drug using network, through exposure, while also increasing the chance of non-testing by lack of awareness of HIV transmission risks . Greater utilisation of testing also produces increased opportunities for education, counselling, and case management, with testing being the first step in management of HIV-infected individuals .
The rates of sharing of equipment in the studied PWID sample are a cause for concern, investigation, and education, as equipment sharing has been linked to HIV transmission independently of syringe sharing . HIV transmission education needs to incorporate communication of the risk posed by all types of equipment sharing, not just syringe. This is pertinent in our sample, as we showed different rates between sharing of syringe and equipment, with sharing of equipment being more prevalent. Whether this relates to a gap in knowledge of HIV transmission, or just an artefact of drug culture, remains unknown.
NSP participants used more home-made drugs than PDI clients, with statistically significant differences, which can be considered as one of the important factors for more risky behaviour. This drift away from traditional opiates, such as heroin, to home-made and stimulant drugs has been noted by other studies, including ex-Soviet countries , and has promoted the need for adaptive programs to capture new and different PWIDs still at risk of HIV acquisition, but not part of the traditional drug scene . Program changes need to be aware of the ever-changing drug landscape and incorporate the needs of a range of PWIDs into their implementation for holistic catchment of those at risk of HIV acquisition.
It was interesting to reveal that NSP clients did not always use syringes from the needle and syringe program. This presents several risks, such as equipment risks from repeated needle use and blunting with larger bore needles . It can be considered that strict drug law and policy contributes to lack of accessibility to needle and syringe program, especially punishment measures on NSP participants and harassment of NSP staff, negatively affecting clean needle distribution among PWIDs. Criminalisation of clean needle exchange and possession has been related to increased needle reuse frequency in other locations . In addition, the stigma that comes with criminalisation can negatively affect prevention activities and service efficacy, as shown in Africa  and Sub-Saharan Africa . Criminalisation and punishment is thought to not be effective in preventing rising HIV incidence . Studies of Georgian PWIDs found that between 9% and 24% of surveyed PWIDs had been subject to an administrative sentence due to drug use and between 1.2% and 5.5% of the subjects had been imprisoned . Global efforts have highlighted the dual risk of high rates of injecting drug use and drug criminalisation, with efforts made to decrease HIV incidence around injecting drug use with assistance from criminal policy change, but so far, these have fallen much below their intended incidence reduction targets . This is very relevant to the Georgian drug environment.
Social demographic characteristics, together with risky injecting and sexual behaviours, suggest that the NSP includes PWIDs that are more vulnerable and in greater need of HIV services. Other Georgian-based studies have found that lower rates of HIV testing and transmission knowledge were associated with lower levels of education and younger age , an association shown in other locations also . Therefore, those with a potentially lower social demographic status represent a higher risk population among Georgian PWIDs. The follow-on risk of this is that those with lower rates of testing were more likely to partake in sharing behaviours, and it was also shown that between 45.8% and 64.0% of PWIDs sampled erroneously considered themselves to be at “low or no risk” for HIV transmission . The relationship between self-assessment of HIV risk with risk behaviour is not linear or logical . This further highlights the importance of HIV transmission risk knowledge and education, particularly in higher risk and vulnerable groups, as the relationship is more complex than it would seem. Other studies have discussed the risks and figures of unknown blood-borne infections in PWIDs and qualified the risk that low levels of testing and disease status knowledge can affect risk of the PWID’s social network . Unknown blood-borne infection risk has been shown to be associated with increased risk behaviour . As the perception of risk, testing frequency, and social demographic status are complexly linked, programs need to ensure catchment of a variety of participants, to balance the risks that come from the complicated psychological nature of behavioural risk.
For PWIDs in the both samples, sex behaviour was more risky than drug behaviour, as sex risk scores were greater than drug Risk in both NSP and PDI groups. Risky sexual behaviour is a transmission risk in of itself, but also compounds risk in PWIDs . Among Georgian PWIDs studied in other samples, HIV sexual transmission risk did not seem to be applied when having sexual contact with a non-regular partner and this result was potentially hypothesised to be related to a belief that sex with a non-regular partner is not a risk for HIV transmission . It has also been noted by other studies, however, that sexual risks are harder to change in participants than drug risk . This could guide further program formation with scope for increased sexual risk education, and the awareness of not only the complexity of sexual risk and risk behaviour, but also the difficulty of change could lead to more innovative and focussed program changes.
According to analyses of Sexual Risk Index, female PDI participants had less risky behaviour than male PDI participants; we found the opposite among NSP male and female participants, with female NSP clients participating in more risky sexual behaviour, which could be related to participating in paid sex. Higher rates of risky sexual behaviours in females have been found in other studies, in reference to paid sex and condom use [24, 25], and potentially inversely-related drug and sexual risks noted due to paid sex and economic independence, which could explain some of the discrepancy between male and female drug and sex risk . Female PWIDs have been previously identified as higher risk for HIV infection compared to male PWIDs [16, 27], and their under-representation in these Georgian harm reduction activities indicates a population at risk of increased HIV acquisition and in need of greater targeting.
Interventions addressing the risks of sexual transmission of HIV among PWIDs and between PWIDs and their sexual partners, and onwards to other populations, are urgently required. The dual risk of injection practise as well as sex risk has been well documented, and this compound dual risk has been noted to be an important factor in HIV spread . PWIDs have been found in some locations to be twice as likely to have multiple partners and practise low levels of condom use . Programs tailored to PWID needs have been shown to have statistically significant positive effects on sexual risk behaviour in other locations . The awareness of this should guide program implementation due to the weight of risk placed on PWID populations when dual risk is present.
Additionally, our analysis suggests that young people from the PDI sample have less Drug Index risk than older PDI people, the difference of which was statistically significant. This difference was not seen in the NSP sample with any statistical significance. Young Georgian PWIDs people have previously been identified as a target population in need of intensified harm reduction efforts, with young peer educators and school programs recommended to decrease the risk of harmful activities among this population . The increased risk that young people are placed at in regards to HIV transmission has been noted in other studies [16, 22, 24, 26] and it has been hypothesised that younger people assess themselves at a comparatively lower risk related to gaps in the HIV transmission knowledge . As stated, younger people have been shown in other locations to be less likely to have ever been tested for HIV . Again, it is the complex interplay of age, self-risk assessment, and practise that creates a comparatively high-risk environment for young people and education, underscoring the need for broad catchment of participants, tailored and focussed harm reduction activities, and multimodal program implementation.