Study from Australia is the first to evaluate a population-level roll-out of pre-exposure prophylaxis (PrEP) in men who have sex with men.

Rapid, targeted, and high-coverage roll-out of pre-exposure prophylaxis (PrEP) to men who have sex with men was associated with a reduction in HIV diagnoses by 25% in one year across New South Wales (Australia), according to a study published in The Lancet HIV journal.

Diagnoses in men who have sex with men across New South Wales reduced from 295 cases in the year before PrEP roll-out to 221 cases in the year after - the lowest levels recorded since the beginning of HIV surveillance in 1985.

The study, led by the Kirby Institute at UNSW Sydney, followed 3,700 men who had been dispensed PrEP as part of the roll-out and found generally high levels of adherence. In this group, the incidence of HIV infection was less than 1 in 2,000 per year, compared with an expected incidence of 2 per 100 per year or higher in the absence of PrEP.

Randomised controlled trials have previously demonstrated the efficacy of PrEP. In addition, mathematical models have predicted that PrEP can have a large and fast impact if rolled out rapidly and at high coverage for people at risk. However, empirical studies to confirm PrEP's population-level effectiveness have not tested these findings until now.

The study in New South Wales was possible due to the existing surveillance system for recent HIV infection in the area, which allowed researchers to quickly document the population-level effect of PrEP. It illustrates the successes possible with effective roll-out of PrEP. Read more via the Lancet