This is the largest published quantitative study of HBV, HCV and HIV among PWID in South Africa to date. The study demonstrates a significantly higher prevalence of HCV infection among PWID (43%) than previously known [23]. Notably, HCV prevalence among PWID in Pretoria was substantially higher than in other cities. This study did not explore the reasons for this geographical variation. However, expert consultation in other settings has suggested that injecting practices as a drug using culture have been in existence for longer in Pretoria than other cities, potentially suggesting a reason for this finding [24].
A large proportion of the participants lived on the street, accounted for by the recruitment of participants through existing harm reduction services that target people from lower socio-economic circumstances. People who live on the street often have limited financial resources to purchase injecting equipment, contributing to the increased likelihood of reuse, sharing and use of contaminated injecting equipment [25]. People living on South African streets who use drugs have little or no access to private spaces to do so, and frequently experience human rights violations, including assault, confiscation of possessions (including injecting equipment) and being moved [26,27,28]. Consequently, conditions for safe injecting are limited. The multivariate analysis found an increased likelihood of HCV infection among people living on the street, reinforcing the importance of addressing social and structural factors to enhance HIV and HCV health outcomes.
The study found that HCV risk is positively associated with increased injection frequency. This is supported by the per injection risk without 100% access to sterile injecting equipment [29]. The high level of reported use of new needles is surprising, and may reflect a social desirability bias, considering that the majority of people inject four or more times a day and access to sterile injecting equipment is limited. Existing harm reduction services in these cities distribute between 10 and 14 sterile needles and syringes at each encounter with a PWID client, with these projects aiming to visit locations where PWID are provided with services once or twice a week.Footnote 1 An assessment of needle and syringe service coverage in Pretoria and Cape Town was completed in 2017 and results are forthcoming [24]. The reported levels of needle and syringe sharing highlight the need for increased saturation of needle and syringe services.
Overall, few PWID (5% of the sample) had access to OST in these cities, which is to be expected as OST remains in the pilot stages [16]. It is also unclear if the reported OST access was sustained or over limited periods and if the dosage was aligned to global recommendations [8].
High coverage of OST and needle and syringe services can reduce the risk of HCV infection by 74% [30]. Modelling data from Kenya (PWID population of 50,000 with HCV prevalence of 11%) shows that providing 75% needle and syringe coverage and 50% OST would reduce the risk of HCV incidence among PWID by 69% by 2030, and elimination targets would be reached through the addition of treating chronic HCV infections among 1000 PWID over 5 years [31].
This research confirmed the findings of a previous study that documented elevated HIV prevalence among PWID compared to the general population [21]. In multivariate analysis, HIV infection is significantly associated with HCV serostatus, highlighting the shared transmission routes of these viruses and the need to integrate viral hepatitis and HIV services for PWID. The study also documents HBsAg prevalence similar to the general population [4]. While a relatively small proportion of people were found to be co-infected with HBV/HCV/HIV, the added morbidity and mortality requires that co-infection remains an important area for consideration. The relative exclusive prevalence of HCV genotypes 1a and 3a is similar to that in other countries where HCV infection is predominantly spread through sharing contaminated injecting equipment among PWID [32, 33]. However, of note in South Africa, genotype 5a (a predominant genotype in patients with liver disease [34]) was not found among PWID and suggests that 5a circulates in the general population and not in PWID.
Participants in this study were recruited from among those who currently access or who were reachable to organisations implementing harm reduction services, specifically mobile needle and syringe distribution and collection services in these cities. Unsurprisingly, the participants were overwhelmingly male given that globally, a higher proportion of PWID are male compared to female, with the proportion of female PWID ranging from 3% in South Asia to 33% in Australasia, and 12% in sub-Saharan Africa [7]. Programmatic data from the services that operate in these cities reflects that between 10 and 13% of service users are women [35]. While this is possibly due to higher numbers of men who inject drugs than women in South Africa, it also likely reflects barriers preventing women who inject drugs from accessing harm reduction services—including stigma, discrimination and services that do not address their specific needs [36]. Previous studies among South African and African PWID also included a smaller proportion of women who inject drugs [21, 37]; however, globally, a higher proportion of women who inject drugs are reached [38]. Nevertheless, there is global [39] and sub-Saharan [40] recognition of the need for gender-appropriate and specific HIV and HCV services for women who inject drugs due to their specific needs.
A diverse cross-section of South African racial groups was recruited across sites, indicating that substance use and injecting practices are issues affecting people across race or ethnicity. The relative order of the size of racial groups in the study sites reflected the demographic characteristics of the relevant cities [41]. However, the relative over-representation of white PWID remains (27% of the sample, versus 8% of the general population) [41]. It is not clear from this study if there are relatively more white PWID or if this is due to selection bias. Most of the study sites where centrally located in areas where PWID congregate. Non-white PWID living in poorer, peripheral areas of the city may have not been reached by existing harm reduction services and therefore not recruited in the study. There is no published evidence supporting different levels of stigma around injecting drug use among different racial groups in these cities, but this may also have been a factor. It is also unclear why lower HCV risk was found among black PWID. Data was not collected on length of participant injecting history, so no analysis can be made on associations between injecting history and race groups as a proxy for other factors.
The findings from this study around substance use reflect substance use treatment data that shows the prevalence of poly drug use in South Africa and different usage patterns across the country [35]. Study and treatment data point to heroin being the most commonly injected drug, and methamphetamine/ATS injecting being highest in Cape Town.
Proportionately more women than men reported sexual activity in the previous month and condom use was similarly sub-optimal. More women than men reported transactional sex for drugs, which has previously been identified among women who inject in South Africa [21].
Interestingly, men who reported recent sexual activity showed lower risk drug use practices than their counterparts who did not report being sexually active. This may be because higher frequency of opioid use is associated with reduced libido, and can induce impotence among men [42]. It may therefore be that men engaging in regular sexual activity are those using less opioids, and are therefore able to exercise greater care with each instance of injection. It may also be that sexual activity is indicative of the existence of intimate partnerships that impact on risky injecting behaviours. While intimate couples who inject drugs together often engage in needle sharing and higher risk injecting practices within the couple [43], there is also increasing evidence that drug use tends to lessen when people have close social relationships and that couples set negotiated standards and limits to such use [44]. This can include agreements about where, when, how, and with whom drugs are injected [45]. Furthermore, concerns for placing primary sexual partners at risk of infectious diseases may contribute to safer injecting [13]. These limits on injecting behaviour in intimate relationships may be some of the reasons that recent sexual activity was found to be generally protective against HCV infection.
Limitations
The opportunistic nature of the sampling method prevents extrapolation to larger PWID populations in these cities and beyond. However, the findings confirm previous local studies and global experience. Information bias may have influenced the reliability of measures assessing substance use and sexual activity (including under reporting of anal sex and exchange of sex for drugs and/or goods). The low frequency of reported alcohol or substance use at the time of sex in Durban is suspected to be an underestimation, as other sexual risk practices were similar to the other cities. This difference could be attributable to several factors. One factor may have been due to differential solicitation of this question by study team members in Durban compared to the other cities. Another potential explanation is potential differences in social norms around discussing sexual practices among PWID in the various cities; however, there is no published evidence supporting this. The researchers were experienced in working with PWID so PWID were likely to feel safe in participation; however, the reporting of favourable (less risky) practices may have been encouraged by the fact that participants were engaging with the same people who provided harm reduction services. This may have resulted in underestimation of HCV risks and over-estimation of access to and use of needle and syringe services.
