avian influenza /ā″vē·ən/ , a highly contagious viral disease of birds caused by an influenza A virus; it occurs in both mild and severe forms. The severe form is highly pathogenic and can result in a mortality rate for birds that can reach 90% to 100% within 48 hours. It may be transmitted to humans through contact with bird droppings or surfaces contaminated by them or through intermediate hosts such as pigs. Person-to-person transmission appears to be rare. Symptoms of avian influenza in humans range from typical influenza-like symptoms to eye infections, pneumonia, acute respiratory distress, and other severe and life-threatening complications. The only means of control when avian influenza has been observed in a flock of domestic fowl is destruction of infected birds and disinfection of the farm. Also called bird flu.
