Margaret Chan, a bird flu expert from Hong Kong, said the danger was particularly severe in poor countries, the BBC said Friday. Chan warned of a possible new flu pandemic, particularly if the flu migrates to countries with poor healthcare and people were already affected by immune-system depressing diseases.
"The next pandemic, if it occurs, will be very devastating," she told the BBC. "We are very concerned of the likelihood of a pandemic."
She said she was concerned about reports of an outbreak on a poultry farm in Vietnam, the first in that country in nearly a year.
Chan also identified healthcare in Africa, particularly for women, as a WHO priority.
"I want my leadership to be judged by the impact of our work on the health of two populations: women and the people of Africa," Chan said.
Chan, the first Chinese citizen to lead a U.N. agency, replaced South Korea's Lee Jong-wook, who died suddenly last year.