Nearly four years in to her five-year tenure at the World Health Organisation, Hong Kong-born Margaret Chan has overseen the response to some of the world's biggest health threats in decades: swine flu and the H1N1 outbreak, the first pandemic to be rated at level six by the WHO since the 1968 influenza crisis.
In April this year, she also courted controversy by praising the quality of North Korea's medical facilities (even though malnutrition is a problem in that country) - a significant departure from comments made by her immediate predecessor, Lee Jong-wook.
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