Deputy President Kgalema Motlanthe will jet off to Vienna, Austria, on Friday to participate in the 13th International Aids Conference, which begins on Sunday.

Joined by outspoken Aids prevention and treatment advocate Health Minister Aaron Motsoaledi, Motlanthe will address a session on Sunday, the opening day of the conference, the Presidency said in a statement.

After a period of questioning the link between the HI-virus and the immune-devastating disease Aids, the South African government has changed tack and aims to have at least 15-million people tested for the virus by June next year. It further wants to significantly increase dispensing the medicine that improves the quality of life of people with the virus.

Motlanthe will take part in a panel discussion on changes in approaches to HIV prevention and treatment, with former US president Bill Clinton among those joining the conference, to be held at the Messe Wien.

He will also pay a visit to Austrian President Heinz Fischer and will open the South African exhibition at the conference, which will include a reference to former President Nelson Mandela who celebrates his 92nd birthday on Sunday.

Although the programme notes are peppered with words like "paradigm shift" and "stakeholders", the organisers say that speakers will not be allowed to simply read from speeches, but will be expected to debate and share information.

The theme will be "Rights here, right now" with a focus on the measures that need to be in place to protect those most vulnerable to and affected by HIV, "especially women and girls, people who use drugs, migrants, prisoners, sex workers, men who have sex with men and transgender persons".

Vienna was chosen as the host city because it is in a region experiencing one of the fastest growing epidemics - fuelled mostly by injecting drug use.