Our big concern at the moment is a virus called H5N1 flu -- some of you call it bird flu -- which first emerged in southern China, in the mid-1990s, but we didn't know about it until 1997.
目前我们最大的担心是一种叫做H5N1的流感病毒， 有些人称其为禽流感 最早在20世纪90年代中期出现于中国南方， 但直到1997年我们才对它有所认识。