http://www.bbc.co.uk/news/health-20545587
Treating people with HIV who have uninfected partners significantly reduces transmission rates, researchers in China have found.
A clinical trial had shown benefits of antiretroviral (ARV) treatment before.
But this trial, reported in the Lancet, is the first "real-life" public health programme of its kind.
A UK HIV expert said there was a growing consensus that getting ARV drugs to as many people as need them would cut transmission rates.