How universal does universal test and treat have to be?

HIV treatment as prevention, not only of HIV-related disease but also of transmission, was proposed in 2006 as a means to end the epidemic.1 Several influential studies and models predicted that early treatment of most people who live with HIV (PLWH) could reduce HIV transmission rates to near zero, at the population level.1, 2, 3 As a result, treatment as prevention evolved into the universal HIV test-and-treat (UTT) approach, which entails offering HIV counselling and testing to an entire population and ART to all PLWH. In 2014, UNAIDS announced ambitious new goals to “end AIDS by 2030” by reaching 90-90-90 targets by 2020: 90% of PLWH knowing their status, 90% ART coverage among those knowing their status, and 90% viral suppression among people on ART.