Testing men who have sex with men for HIV and immediately treating those who are HIV positive could greatly reduce new infections among the MSM population as a whole, at least in the Netherlands. Publishing their findings in Science Translational Medicine, researchers analyzed medical records data as well as genetic information about the virus in 617 recently diagnosed Dutch MSM, in order to make estimates about the likely source of their infections.

An estimated 71% of the new HIV cases transmitted from undiagnosed men, 22% from men who were diagnosed but not on treatment, 6% from men who had started treatment, and 1% of diagnosed men who had not been linked to medical care within 18 months. About 43% of the transmissions derived from men infected for less than a year.

The researchers estimated that 19% of the new HIV cases could have been averted if MSM tested annually for HIV and if those who tested positive were immediately provided treatment. Two-thirds of cases could have been averted if all men testing positive received ARVs and if Truvada as PrEP was provided to half of all men testing negative. The researchers concluded that their findings support making PrEP available worldwide. Read more via Science Magazine