Virulent avian influenza is a highly contagious viral disease, which may cause up to 100% mortality in domestic fowls. The disease is caused by a virus belonging to the family: Orthomyxoviridae.
All commercial, domestic and wild bird species are susceptible but disease outbreaks occur more frequently in turkeys and chickens. Infection may be brought into a country by migratory wild birds. Many species of waterfowl, especially geese and ducks carry the virus but generally show no signs of disease. Generally, humans are not affected, but an outbreak of influenza in humans was associated with an avian source in Hong Kong - January 1998.
Some images included here are published with permission from Dr. Ilaria Capua, and are part of the book "A Colour Atlas and Text on Avian Influenza" written by I. Capua and F. Mutinelli, 2001. The book reports the clinical, pathological, virological and regulatory aspects of the 1999-2000 H7N1 epizootic of mildly and highly pathogenic avian influenza in Italy (All images are subject to copyright).
