United Nations Secretary General Antonio Guterres has appointed Ms Winnie Byanyima as the new HIV/AIDS chief.

Oxfam International executive director Winnie Byanyima of Uganda will lead UNAIDS, a spokesperson for Guterres said in a statement.

Ms Byanyima has held several roles that affiliated to the governance of the African Union, and has influenced the international agenda at the United Nations through her leadership in many coalitions of civil society organizations.

She, at the time of her appointment, was the Executive Director of OXFAM, a position she has held for six years since her appointment in January 2013.

Ms Byanyima is taking over from Micheal Sidibe who stepped down in May this year following accusations of ''serious mismanagement''. Mr Sedibe was also accused of creating "a patriarchal culture tolerating harassment and abuse of authority."

An Independent Expert Panel (IEP) report commissioned by UNAIDS's governing body said the agency's culture under Sidibe also failed "to uphold the United Nations' laws and values."

Ms Byanyima has been the Executive Director of Oxfam International since 2013. Prior to that, she served for seven years as the Director of Gender and Development at the United Nations Development Programme.

Ms Byanyima began her career as a champion of marginalized communities and women 30 years ago as a member of parliament in the National Assembly of Uganda. In 2004, she became the Director of Women and Development at the African Union Commission, working on the Protocol on the Rights of Women in Africa, an international human rights instrument that became an important tool for reducing the disproportionate effect of HIV on the lives of women in Africa.

She holds an advanced degree in mechanical engineering (in energy conservation and the environment) from the Cranfield Institute of Technology and an undergraduate degree in aeronautical engineering from the University of Manchester.

ALSO READ: Winnie Byanyima steps down as Oxfam boss