The HPAI virus is capable of affecting a wide variety of wild fowl, particularly migratory waterfowl. There is evidence that migratory birds tend to be a prime source of bird flu pathogen transmission. So, strengthening surveillance of the epidemic situation in migratory birds is of great help in tracing the origins of an epidemic. On this occasion the large-scale, multinational and concurrent outbreaks of avian influenza may be associated with the virus being spread during the migratory birds' seasonal migrations.

(China.org.cn February 13, 2004)