People who inject drugs in prison: HIV prevalence, transmission and prevention.

In 2011, over 10.1 million people were held in prisons around the world. HIV prevalence is elevated in prison and this is due to the over representation of people who inject drugs (PWID). Yet HIV prevention programs for PWID are scarce in the prison setting. With a high proportion of drug users and few prevention programs, HIV transmission occurs and sometimes at an alarming rate. This commentary focuses primarily on drug users in prison; their risk behaviours and levels of infection. It also comments on the transmission of HIV including outbreaks and the efforts to prevent transmission within the prison setting. The spread of HIV in prison has substantial public health implications as virtually all prisoners return to the community. HIV prevention and treatment strategies known to be effective in community settings, such as methadone maintenance treatment, needle and syringe programs, condoms and antiretroviral therapy should be provided to prisoners as a matter of urgency.