Health authorities said Saturday they have found a chicken in a central region infected with avian influenza (AI), the first such case, raising an alarm that the deadly bird flue disease might be spreading. Cases of AI reported so far all involved ducks. The latest case involving a chicken was reported at a farm in Buyeo, a town about 150 kilometers from where the poultry disease was first detected at a duck farm in North Jeolla Province a week ago.