Overview of effective and promising interventions to prevent HIV infection.

OBJECTIVE: To review the evidence for the effectiveness of a variety of approaches to preventing HIV infection.
METHODS: We reviewed what is known about the efficacy and effectiveness of a range of prevention approaches that are at various stages of research. These interventions attempt to induce behavioural change, apply technologies or modify social environments. Our intention was not to provide an exhaustive review of all types of HIV prevention strategies but rather to illustrate the landscape of interventions that have been developed and evaluated in different settings and that have the potential for widespread application among both adults and young people.
FINDINGS: There is a large quantity of evidence from experimental and observational research as well as from practical real-world experience in both developed and developing countries. This evidence supports the implementation and scale-up of a number of interventions and strategies. At the same time, there is a need to continue to develop new and more effective interventions while attending to a number of behavioural and social issues that cut across virtually all interventions designed to prevent the spread of HIV.
CONCLUSION: We caution against confusing lack of implementation with lack of effectiveness and call for continual improvement in the quality and quantity of evidence. We have also identified a number of important directions for future HIV prevention research.