World Health Organisation chief Margaret Chan on Thursday decided to maintain a pandemic alert nearly a year after she placed the world on maximum readiness for the new swine flu virus.
The WHO is continuing the alert following advice from a panel of scientists that although the outbreak has declined, fresh cases of A(H1N1) influenza are expected in coming weeks mainly during the southern hemisphere's flu season.
"Committee members stressed that it remains critical for countries to continue to maintain vigilance concerning the pandemic," the agency said in a statement.
The announcement followed a teleconference on Tuesday of the committee, comprising 15 scientists headed by Australian infectious diseases expert John Mackenzie.
"Following the advice of the Emergency Committee, the Director-General determined that while the period of most intense pandemic activity has passed, pandemic disease is expected to continue to occur," the WHO said.
It added that the situation will be reassessed by mid July 2010, when full information on the winter influenza season in the south will be available.
Tropical areas of the Caribbean and South Asia are currently the most active areas for the pandemic, with a "relatively low level of resurgence of cases".
However, last year those areas experienced their most intense bouts of swine flu in July, the WHO underlined.
In temperate areas of the southern hemisphere, increases in general influenza activity are within common seasonal epidemic levels, while in West Africa the pandemic flu has largely subsided after a peak in February and March, it added.