Putting HIV positive people on medication earlier and using PrEP as a barrier against the virus is working, according to researchers in San Francisco.

PrEP is the ongoing use of mediation in HIV negative people to dramatically reduce the risk of contracting HIV during sex without a condom.

Along with condom use, the multi-pronged attack is reducing the risk of transmission and improving the health of those who become positive.

There were 302 new HIV diagnoses reported in San Francisco in 2014, the number of new HIV diagnoses in the city has declined between 2007 and 2011, stabilised in 2012, and continued to decline in 2013 and 2014.

The San Francisco AIDS Foundation stated earlier this year that “early treatment gives people better health outcomes, that treatment equals prevention, and that PrEP works”.

The Foundation recommends: “Full access to comprehensive PrEP services for those whom it is appropriate and desired, with support for medication adherence for those using PrEP.”

Although doctors showed some resistance to putting HIV positive people on medication before their CD4 cell count fell below a certain level, the World Health Organisation is now advocating anti-retroviral therapy as soon as people become positive, regardless of cell count.

The HIV Foundation Queensland is currently conducting a year-long study into PrEP, specifically to see how gay men adhere to the medication and how it can best be distributed across the state.

Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told the New York Times: “I love the San Francisco model”.

“If it keeps doing what it’s doing, I have a strong feeling that they will be successful at ending the epidemic as we know it. Not every last case—we’ll never get there—but the overall epidemic. And then there’s no excuse for everyone not doing it.”