The researchers have concluded that the risk of getting HIV from an undetectable partner is virtually zero. During the two years of the study so far, none of the HIV negative partners became infected with HIV by their partners . The results were the same, even when taking into account the high levels of co-infection with other STI’s observed in the gay participants. This builds further on the Swiss Statement released in 2008, which declared that people who have HIV but are undetectable, did not transmit HIV, although this study did not look at the issue of co existing STI’s
I have to stress that this is an ongoing study that will not be finalised till 2017 and the best way to prevent catching HIV, is by having protected sex.