Implementing harm reduction programs among imprisoned and newly released injection drug users (IDUs) dramatically slows the spread of HIV. Publishing their findings in PLOS Medicine, researchers studied two populations in Thailand: 3,851 IDUs testing positive for HIV upon entering prison between 2004 and 2010, and 4,357 people who were released from prison as a part of an amnesty program in 2007. The study examined the effects of a harm reduction program that included methadone maintenance therapy, syringe programs, health education and antiretroviral treatment.

The HIV incidence, or annual rate of new infections, among the imprisoned IDU population dropped from 18.2 percent in 2005 to 0.3 percent in 2010. These figures fell in tandem with the cumulative viral load among those IDUs living with the virus.

There were 2,473 participants of the amnesty group who tested negative for the virus in January 2006 and who had interviews at six- to 12-month intervals from that point until 2010. Their attendance at methadone clinics was linked with an 80 percent reduction in HIV incidence. Using syringe exchange programs frequently was also associated with a lower incidence of HIV: There was a zero percent incidence among very-frequent users of the programs, compared with 0.5 percent of those who did not use the programs.

To read the NIH release, click here.

To read the study, click here.