Vietnamese workers in protective clothing feed chickens at a poultry farm in the outskirts of Ho Chi Minh City. Vietnamese workers, covered from head to toe in protective clothing, feed chickens at a poultry farm in the outskirts of Ho Chi Minh City February 23, 2005. The indoor farm, which has not seen a single case of disease or infection since it opened in 2001, is a model for others. The world is overdue for an influenza pandemic and it must act swiftly to prevent one being triggered by bird flu now endemic in parts of Asia where it has killed 46 people, U.N. officials said on Wednesday. REUTERS/Adrees Latif