A major research review has found that injection drug users (IDUs) on methadone treatment are 54 percent less likely to contract HIV, according to a study published in the online edition of the British journal BMJ and reported in The New York Times.

The study was conducted by a group of researchers from the United Kingdom, Italy, the United States, Canada and Australia. The consortium analyzed a dozen published studies with information concerning opiate replacement therapy’s impact on HIV transmission; pooling data from nine of these studies, researchers identified 819 HIV infections spanning 23,000 person years.

The scientists suggested that the dramatic risk reduction was due to the fact that methadone improved drug users’ ability to adhere to HIV medications—which in turn reduced their likelihood of infecting others—and to refrain from sharing needles or from exchanging sex for drugs. However, given that those who commit to methadone treatment may also be more motivated toward risk-reducing behaviors, methadone on its own may not be the full cause of the 54 percent reduction.

The findings are vital, however, for efforts to push for opiate-replacement programs in countries such as Russia where injection drug use is rampant and is a major driver of new HIV infections, but where methadone remains illegal.

For the New York Times story, click here.

For a PDF of the research paper, click here.