Law enforcement influences on HIV prevention for injection drug users:

Law enforcement activity has had multiple influences on injection drug users' (IDUs') participation in a cross-border HIV prevention project in southern China and northern Vietnam. The project has successfully achieved and maintained the official support of police and other government agencies and effectively implemented its interventions. However, analysis of process data, site visit observations, and interviews with project staff, peer educators, IDUs, and police officers reveal the ongoing effects of actual and perceived threats from law enforcement, as well as community stigmatisation, on IDUs' project participation. These effects are discernible in variations in the monthly numbers of needles/syringes provided, cross-border differences in IDUs' preferred ways to receive new needles/syringes and retain used needles/syringes for exchange, and geographic patterns of IDUs' receiving and redeeming pharmacy vouchers. HIV prevention programmes must not only maintain the support of police and other officials but also convince IDUs that it is both beneficial and safe for them to participate in the interventions. Programmes must also be implemented with flexibility, adapting to the potentially changeable preferences, perceptions, and needs of IDUs.