Syringe exchange: HIV prevention, key findings, and future directions.

HIV among injecting drug users (IDUs) has now been documented in over 60 countries in the world, and there are an additional 40 countries where injecting drug use has been reported including widespread epidemics in Southeast and southern Asia and in Latin America. At present HIV infection is almost always fatal, and there is no promise that a preventive vaccine will become available soon. Given the enormity of the HIV epidemic among IDUs and the critical need to reduce the spread of HIV transmission to and from IDUs, prevention efforts are essential. Syringe-exchange programs have become a major component of HIV prevention strategies in most developed countries and work within the philosophy of harm reduction. Increasing access to sterile syringes has been met with considerable controversy. Opponents of syringe exchange have generally argued that increasing access to sterile syringes would simultaneously increase the number of injecting drug users, increase the frequency of injection for already active IDUs, and appear to "condone" an illegal behavior. To date many research studies and four major reviews of syringe exchange literature have been conducted. All studies thus far have shown no increase in illicit drug injection associated with syringe exchanges, and significant decrease in drug risk behaviors.