October 9, 2012
An international team of researchers, in a paper published in the online edition of the British Medical Journal, reported that methadone treatment reduces the risk of HIV transmission in people who inject drugs (PWID). Dr. Julie Bruneau from the CHUM Research Centre and the Department of Family Medicine at the Université de Montréal -- one of six investigators working with the principal investigator, University of Bristol's Dr. Matthew Hickman -- notes that the study provides evidence of a link between opiate substitution therapies (OST), including methadone, and a reduced risk of HIV transmission.
The study results are significant, as approximately 510 percent of HIV infections worldwide are due to injection drug use -- a major risk factor for the transmission of HIV and AIDs -- and increases in HIV incidence have been reported among PWID in many countries where OST are illegal or severely restricted.
Researchers from the United States, Canada, Italy, and Australia collaboratively reviewed and analyzed several published and unpublished studies from multiple countries to determine the relationship between OST and HIV transmission among PWID. The team selected nine studies that looked mainly at males between 26 and 39 years of age, with a total of 819 cases of HIV infection accumulating 23,608 person-years of follow-up.
Through their analysis, the researchers determined that the impact of OST on HIV reduction was strong -- OST was associated with a 54 percent reduction in risk of HIV infection among PWID. Because of differences in the studies, including different background rates of HIV infection, the researchers were unable to calculate an "absolute risk reduction" for HIV infection that was applicable to all settings.