The new director general of the World Health Organization Tedros Adhanom took over managing the UN health agency, the WHO said.
A specialist in malaria, Tedros served as health minister and later as foreign minister for Ethiopia.
The 52-year-old is the first African to head the global health organisation, and he takes over from Margaret Chan of China, who led the WHO for nearly 10 years.
Tedros was elected to the post in May in what was the first time the WHO director general was chosen by the World Health Assembly from among multiple candidates. Previously, a single nominee had been chosen by the executive board.
The Geneva-based WHO, with some 8,000 employees worldwide, is responsible for coordinating global action to disease outbreaks and epidemics, such as Ebola, and for setting the norms for health systems in all countries.
