What is avian influenza?
Avian Influenza, or “bird flu”, is a contagious disease of animals caused by viruses that normally infect only birds and, less commonly, pigs. Avian Influenza viruses are highly species-specific. On rare occasions, these viruses cross the species barrier to infect humans. The infection of domestic poultry with avian influenza viruses causes two main forms of disease with either high or low extremes of virulence. The so-called “low pathogenic” form commonly causes only mild symptoms with ruffled feathers and a drop in egg production that may go undetected. The highly pathogenic form, known as highly pathogenic avian influenza (HPAI) is far more virulent, spreading rapidly through poultry flocks, affecting multiple internal organs with a mortality that approaches 100%, often within 48 hours.
Avian influenza, commonly called “bird flu,” is an infection caused by influenza viruses that occur naturally in birds. Wild birds can carry the viruses, but usually do not get sick from them, but some domesticated birds, such as chickens, ducks, and turkeys, can become infected, often fatally. One strain of avian influenza, H5N1, is endemic in much of Asia and has recently spread into Europe. Avian H5N1 infections have killed poultry and other birds in a number of countries.
Avian influenza, or bird flu, is a contagious disease of animals caused by viruses that normally infect only birds and, less commonly, pigs. Avian influenza viruses are highly species-specific, but have, on rare occasions, crossed the species barrier to infect humans. In domestic poultry, infection with avian influenza viruses causes two main forms of disease, distinguished by low and high extremes of virulence. The so-called low pathogenic form commonly causes only mild symptoms (ruffled feathers, a drop in egg production) and may easily go undetected. The highly pathogenic form is far more dramatic. It spreads very rapidly through poultry flocks, causes disease affecting multiple internal organs, and has a mortality that can approach 100%, often within 48 hours.
Avian influenza, or “bird flu”, is a contagious disease of animals caused by viruses that normally infect only birds and, less commonly, pigs. Avian influenza viruses are highly species-specific, but have, on rare occasions, crossed the species barrier to infect humans. In domestic poultry, infection with avian influenza viruses causes two main forms of disease, distinguished by low and high extremes of virulence. The so-called “low pathogenic” form commonly causes only mild symptoms (ruffled feathers, a drop in egg production) and may easily go undetected. The highly pathogenic form is far more dramatic. It spreads very rapidly through poultry flocks, causes disease affecting multiple internal organs, and has a mortality that can approach 100%, often within 48 hours.
