Intravenous drug use and HIV: evidence for action now

Abstract

For many of those lucky enough to have access to effective treatment, HIV/AIDS is increasingly becoming a manageable chronic condition, instead of a death sentence. And the numbers of new infections are declining in some countries, largely because of education, behavioural changes, and the implementation of proven prevention strategies. But for at least one group, intravenous drug users, rates of HIV infection are rocketing.A Sept 15 report by the US Institute of Medicine (IOM), Preventing HIV Infection Among Injecting Drug Users in High Risk Countries: An Assessment of the Evidence, highlights what has become an enormous global public-health challenge. The IOM panel examined evidence for various strategies used around the world. It focused on countries where injecting drug use is becoming the most common pathway to HIV infection—for example, parts of eastern Europe and Asia, where up to 90% of HIV-positive people are also drug users.Injecting drug users contract HIV mainly by sharing contaminated needles and other injecting equipment and engaging in unsafe sexual practices. This risky behaviour leads, in turn, to transmission of HIV to their sexual partners and offspring. Obviously, the most effective way to stop the spread of the virus in this population is to stop drug use. A laudable goal, but easier said than done.Alternative strategies have thus had to be developed. The IOM panel examined the evidence for three kinds of strategies: drug-dependence treatment, with both pharmacological and psychosocial interventions, needle-exchange and syringe-access programmes, and outreach and education programmes. The strategies were assessed for their effects on drug-related risk, sex-related risk, and HIV transmission.With respect to drug-dependence treatment, the panel found strong evidence of effectiveness for the opioid antagonists methadone and buprenorphine when they are used in sufficient doses for a reasonable length of time. These drugs, which prevent withdrawal symptoms and reduce drug cravings, reduce illicit drug use. Unfortunately, no pharmacological treatment for addiction to stimulants, such as methamphetamine, has been found to be consistently effective.Needle-exchange and syringe-access schemes, while often socially controversial, show consistent evidence of efficacy against drug-related behaviour when used as part of a multicomponent HIV-prevention programme, and have been previously recommended by WHO and other organisations. Intravenous drug users who participate in these harm-reduction strategies have, by self-report, decreased sharing of drug paraphernalia, unsafe injection, and injection frequency. Some governments are wary of these interventions for fear they will have unintended adverse consequences, such as the creation of new drug users and increased crime rates, but there is no evidence that this is the case. The report acknowledges, though, that few studies have been designed to look at such unintended consequences, so further investigation is needed to definitively address these concerns. The panel found evidence that outreach and education services reduce self-reported risky drug-related behaviours, including overall use, frequency of injection, reuse of needles, syringes, and other paraphernalia. On the other hand, psychosocial interventions, such as cognitive behavioural therapy, when used without pharmacotherapy, have not been shown to work.What is the effect of the above strategies on high-risk sexual behaviour? The evidence is not especially compelling when any of these treatments are used in isolation. The panel instead recommends that programmes focusing on drug-related risk need to be combined with interventions that specifically focus on sexual behaviour.The final crucial question is how well these strategies work in reducing the transmission of HIV. Most studies have been designed to measure effects on risk behaviour, whether drug-related or sex-related, rather than on actual rates of HIV infection. Therefore, although there is some evidence that continuous drug-dependence treatment protects against seroconversion, and that needle-exchange programmes can reduce HIV prevalence, there is a need for more robust studies.This report clearly shows that many questions remain to be answered about the constituents of an ideal programme for mitigating the effects of intravenous drug use on HIV/AIDS. But the report still serves as a valuable synthesis of the existing evidence on available strategies. All countries, particularly those with increasing rates of HIV infection, can—and should—use this evidence now to devise and implement multicomponent programmes that reflect their specific economic, cultural, and social circumstances. For many of those lucky enough to have access to effective treatment, HIV/AIDS is increasingly becoming a manageable chronic condition, instead of a death sentence. And the numbers of new infections are declining in some countries, largely because of education, behavioural changes, and the implementation of proven prevention strategies. But for at least one group, intravenous drug users, rates of HIV infection are rocketing. A Sept 15 report by the US Institute of Medicine (IOM), Preventing HIV Infection Among Injecting Drug Users in High Risk Countries: An Assessment of the Evidence, highlights what has become an enormous global public-health challenge. The IOM panel examined evidence for various strategies used around the world. It focused on countries where injecting drug use is becoming the most common pathway to HIV infection—for example, parts of eastern Europe and Asia, where up to 90% of HIV-positive people are also drug users. Injecting drug users contract HIV mainly by sharing contaminated needles and other injecting equipment and engaging in unsafe sexual practices. This risky behaviour leads, in turn, to transmission of HIV to their sexual partners and offspring. Obviously, the most effective way to stop the spread of the virus in this population is to stop drug use. A laudable goal, but easier said than done. Alternative strategies have thus had to be developed. The IOM panel examined the evidence for three kinds of strategies: drug-dependence treatment, with both pharmacological and psychosocial interventions, needle-exchange and syringe-access programmes, and outreach and education programmes. The strategies were assessed for their effects on drug-related risk, sex-related risk, and HIV transmission. With respect to drug-dependence treatment, the panel found strong evidence of effectiveness for the opioid antagonists methadone and buprenorphine when they are used in sufficient doses for a reasonable length of time. These drugs, which prevent withdrawal symptoms and reduce drug cravings, reduce illicit drug use. Unfortunately, no pharmacological treatment for addiction to stimulants, such as methamphetamine, has been found to be consistently effective. Needle-exchange and syringe-access schemes, while often socially controversial, show consistent evidence of efficacy against drug-related behaviour when used as part of a multicomponent HIV-prevention programme, and have been previously recommended by WHO and other organisations. Intravenous drug users who participate in these harm-reduction strategies have, by self-report, decreased sharing of drug paraphernalia, unsafe injection, and injection frequency. Some governments are wary of these interventions for fear they will have unintended adverse consequences, such as the creation of new drug users and increased crime rates, but there is no evidence that this is the case. The report acknowledges, though, that few studies have been designed to look at such unintended consequences, so further investigation is needed to definitively address these concerns. The panel found evidence that outreach and education services reduce self-reported risky drug-related behaviours, including overall use, frequency of injection, reuse of needles, syringes, and other paraphernalia. On the other hand, psychosocial interventions, such as cognitive behavioural therapy, when used without pharmacotherapy, have not been shown to work. What is the effect of the above strategies on high-risk sexual behaviour? The evidence is not especially compelling when any of these treatments are used in isolation. The panel instead recommends that programmes focusing on drug-related risk need to be combined with interventions that specifically focus on sexual behaviour. The final crucial question is how well these strategies work in reducing the transmission of HIV. Most studies have been designed to measure effects on risk behaviour, whether drug-related or sex-related, rather than on actual rates of HIV infection. Therefore, although there is some evidence that continuous drug-dependence treatment protects against seroconversion, and that needle-exchange programmes can reduce HIV prevalence, there is a need for more robust studies. This report clearly shows that many questions remain to be answered about the constituents of an ideal programme for mitigating the effects of intravenous drug use on HIV/AIDS. But the report still serves as a valuable synthesis of the existing evidence on available strategies. All countries, particularly those with increasing rates of HIV infection, can—and should—use this evidence now to devise and implement multicomponent programmes that reflect their specific economic, cultural, and social circumstances.