The Effectiveness of Bleach in the Prevention of Hepatitis C Transmission - Final Report

6. Harm Reduction Programs

Harm reduction programs for people who inject drugs include strategies to prevent initiation of injection drug use, strategies to enhance safe injection among those who are injecting and may emphasize detoxification and rehabilitation services. Although abstinence can be one goal of harm reduction strategies, it should never be a condition of access to services^2,73.

Needle Exchange Programs

Needle exchange programs (NEP) are probably the most common harm reduction initiative. NEPs provide sterile needles to people who use injection drugs and collect used needles for disposal. In theory, if bleach disinfection works, then a cleaned needle is as good as a new needle. We can, therefore, look at the effectiveness of NEPs to evaluate the potential effectiveness of bleach education and distribution programs for injection drug users.

Needle exchange programs were first established in the 1980s as an effort to slow the spread of HIV. Evaluations of these programs and associated research reported that syringe exchanges reduce HIV risk behaviours, slow the spread of HIV infection among people who use injection drugs and do not produce increases in the injection of illicit drugs^74,75. Studies have shown a decrease in HIV seroprevalence in cities with syringe exchanges compared to those without^76,77. They have also reported an increased risk of infection among injection drug users who do not use syringe exchanges compared to those who do⁷⁸.

Other studies, however, have found that NEPs are not sufficient to stop HIV transmission. An Amsterdam cohort study found no association between HIV seroconversion and NEP use between 1986 and 1991⁷⁹. In Vancouver, British

Columbia, an HIV outbreak continued despite a large-scale, established and well-used NEP which was the main source of syringes even for those who seroconverted during this outbreak²³. And a 1997 Montreal study found that the risk of HIV infection was significantly higher - 2 to 10 times greater - among injection drug users who reported recent NEP use compared to those who did not⁸⁰.

For HCV, there is some research that demonstrates a decreased risk of transmission through the use of NEPs. A series of cross-sectional surveys in Glasgow provided evidence that the prevalence of HCV among people who inject drugs had decreased since the establishment of needle/syringe exchanges in that city⁸¹. An evaluation of the Tacoma syringe exchange reported strongly significant associations between non-use of the syringe exchange and HBV and HCV infection75. The authors estimated that use of NEP would have resulted in a 61% reduction in HBV cases and a 65% reduction in HCV cases⁷⁵. And an ecological review of 190 studies from 101 cities worldwide undertaken by the Australian Commonwealth Department of Health and Ageing found that HCV prevalence was lower in cities with NEP compared to cities without NEP. Among new injectors (injecting for three years or less), this review found an average HCV prevalence of 25% in cities with NEP compared to 66% in those without⁷⁷.

However, these limited studies are the only ones that report such success. Many studies report very high HCV prevalence rates in IDU populations (75% to 95%), despite harm reduction interventions⁷⁴. Even with these initiatives, the majority of injection drug users still become infected¹². For example, in Seattle, a cohort study showed no apparent protective effect of NEP use against HBV or HCV infection, and, in fact, injection drug users who had never used the syringe exchange had a lower incidence of HCV than those who did use the exchange⁷⁹. Similarly, in Sweden, a prospective cohort study followed injection drug users who used a local syringe/needle exchange for between six months and two years. None of those drug users who were HIV-negative at the start of the study seroconverted to HIV positive, but 25% of originally HBV-negative injection drug users seroconverted to HBV positive, and 56% of originally HCV-negative injection drug users seroconverted to HCV positive⁸². This suggests the very high transmissibility of HCV despite NEPs. Likewise, the Australian ecological review, while observing reduced prevalence and incidence rates in cities with NEP, found that these cities still had a median HCV prevalence of 60% and averaged incidence rates of over 18 per 100 person years⁷⁷. In Scotland, studies through the 1990s showed that while there was a decrease in HCV prevalence between 1990 and 1997, the trend did not continue past 1997. Implemented harm reduction measures may have helped to reduce the spread of HCV, but were, "not sufficient to bring this epidemic under control and reduce transmission to sporadic levels⁸³."

A potential explanation for the limited effectiveness of NEPs in stopping transmission of HCV infection is that despite access to sterile needles, borrowing and sharing persists^61,81. Hahn et al. reported that despite well established and extensive syringe exchange programs in San Francisco, one third (32%) of surveyed young injectors (under age 30) had still injected with a needle used by someone else in the preceding 30 days⁶¹. In Glasgow, a 1996 cross-sectional survey showed that 16% of recruited injectors who use needle/syringe exchanges had injected with a used syringe within the preceding month and 33% admitted to passing their used equipment onto others⁸¹. And only 19% of injection drug users interviewed as part of the Winnipeg Injection Drug Epidemiology Study reported using a new needle/syringe every time they injected⁸⁴, despite the presence and use of NEPs. These studies highlight that NEPs by themselves do not prevent needle sharing.

Equally important, most NEPs do not address the issue of shared injection equipment other than needles/syringes. This paraphernalia includes spoons, filters, cookers, water, water bottles and even the drugs themselves if they are prepared communally. Among Montreal street youth surveyed, 84% reported first injecting with a clean needle, but only 62% used clean drug preparation equipment⁸⁵. Non-injection drug use, too, often involves sharing pipes and/or straws. Shared injecting, snorting and smoking equipment has been correlated with HCV transmission, and likely contributes to NEPs' lack of success in reducing HCV spread⁷⁹.

Research has shown that certain factors can influence the success of NEP in preventing HCV infection. For example, Hahn et al. reported that obtaining one's first needle from a needle exchange was protective against HCV infection⁶¹. Similarly, starting one's injecting career after the establishment of needle exchange program in the community, rather than before, has been shown to be protective against HCV infection, even after adjusting for length of time injecting drugs⁸¹. These factors must be more closely examined in order to design prevention programs that target high-risk individuals at the appropriate times in their injecting careers.

Overall, the data supporting the efficacy of NEPs are limited, especially against HCV. The reasons for NEP failure are likely diverse and may include difficulty accessing NEPs, inconsistency of use, transmission by equipment not provided by NEPs (e.g., cookers, filters), transmission by non-injection drug use such as snorting cocaine or smoking crack, and/or other individual risk factors. Given the limited NEP efficacy data and the more complicated process that bleach-based sterilization requires, it is unlikely that bleach distribution will be effective in reducing HCV transmission.

Safe Injection Sites

Several European and Australian cities have developed "tolerance zones", " injection rooms", "health rooms" and/or "contact centres". These are supervised injection sites where people who inject drugs can obtain clean injection equipment, condoms, advice and/or medical attention. They often include space where injection drug users can take drugs in a comparatively safe environment, usually under the supervision of medically trained personnel and with access to a full range of sterile injecting equipment^73,86. These are often called "safe injection sites" although this is a misnomer, as safety cannot be assured until the quality and quantity of drugs is also supervised. Supervised injection sites may have more success than NEPs in reducing the transmission of bloodborne pathogens.

The first 'drug rooms' were established in Switzerland in the late 1980s. The number has since grown, and there are now supervised injection sites in Switzerland, Germany, the Netherlands, Australia and the United Kingdom⁷³. The Harm Reduction Action Society has prepared a proposal for a Safe Injection Facility Pilot Project in Vancouver, BC87, and the establishment of such a site has been supported in public opinion polls (71% support) and by the provincial medical health officer⁸⁸. Elsewhere in Canada, the HIV/AIDS Legal Network advocates for the establishment of, "safe injection facilities as part of an overall strategy of more effectively respond to injection drug use and its harms in Canada⁸⁹."

Although there have been few evaluation studies on European supervised injecting centres published in English, available studies provide evidence that such facilities reduce public nuisance, improve access and uptake of health and other welfare service, reduce opioid-related overdose risk and reduce risk of bloodborne virus transmission^73,90,91. Injection drug users view safe injection sites favourably and in cities where they are not yet established, most people who use injection drugs self-report that they would use such sites if they were available^86,92. Whether this would truly be the case is not clear, as other factors may influence use of these sites. However, the acceptability of such sites are supported by the Australian experience, where within six months of opening its doors, the Medically Supervised Injecting Centre (MSIC) registered over 1500 clients and supervised over 11,000 client visits⁹³. Use of the MSIC grew monthly, from 401 visits in May to 29⁸⁸ in October. As well as supervising injections, the MSIC provided 610 referrals for drug treatment, medical consultations and social welfare assistance in this time. MSIC staff also managed 87 drug-overdose related clinical incidence with no adverse sequelae⁹³. The transmission of bloodborne pathogens was not assessed.

While most safe injection sites are inside spaces, some cities and countries have experimented with outdoor "open tolerance zones." Here, people who inject drugs may congregate and use drugs, but the zones are patrolled by police and may be served by NEP, methadone units, crisis centres, medical services and/or other services for injection drug users. The population using these spaces, however, tend to be unstable and volatile and thus these zones have been short-lived⁷³.

Syringe Vending Machines

Another harm reduction measure that has been tested in various sites is syringe vending machines. These are similar to coin-operated soda machines that accept contaminated syringes and mechanically provide sterile syringes in exchange94. Advantages of such vending machines include their 24-hour availability and their provision of anonymous, no-cost needles/syringes^94,95.

In Marseilles, France, a survey conducted after an experimental one-year period with these machines found that they were used regularly and attracted younger injection drug users who were less likely to have had contact with the health care system through participation in drug maintenance treatment programs⁹⁴.

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