BIRD FLU (Avian influenza) is an infection caused by avian (bird) influenza (flu) viruses. These flu viruses occur naturally among birds. Wild birds worldwide carry the viruses in their intestines, but usually do not get sick from them. However, bird flu is very contagious among birds and can make some domesticated birds, including chickens, ducks, and turkeys, very sick and even cause death.
Infection with bird flu viruses in domestic poultry causes two main forms of disease that are distinguished by low and high extremes of virulence. The 'low pathogenic' form may go undetected and usually causes only mild symptoms (such as ruffled feathers and a drop in egg production). However, the 'highly pathogenic' form spreads more rapidly through flocks of poultry. This form may cause disease that affects multiple internal organs and has a mortality rate that can reach 90-100 per cent often within 48 hours.
WHAT ARE THE RISKS TO HUMANS?
The Bird Flu virus does not usually infect people, but more than 100 human cases have been reported. Most of these cases have occurred from direct or close contact with infected poultry or contaminated surfaces; however, a few cases of human-to-human spread of this virus have occurred.
So far, spread of the Bird Flu virus from person to person has been rare and has not continued beyond one person. Nonetheless, because all influenza viruses have the ability to change, scientists are concerned that this virus one day could be able to infect humans and spread easily from one person to another.
HOW DO PEOPLE BECOME INFECTED WITH BIRD FLU VIRUSES?
Most cases of Bird Flu infection in humans have resulted from direct or close contact with infected poultry, for example domesticated chicken, or surfaces contaminated with secretions and excretions from infected birds. The spread of Bird Flu viruses from an ill person to another person has been reported very rarely, and transmission has not been observed to continue beyond one person.
THE SYMPTOMS OF BIRD FLU IN HUMANS
Symptoms of Bird Flu in humans have ranged from typical human influenza-like symptoms (fever, cough, sore throat, and muscle aches) to eye infections, pneumonia, severe respiratory diseases, and other severe and life-threatening complications.
Is there a risk for becoming infected with Bird Flu by eating poultry?
There is no evidence that properly cooked poultry or eggs can be a source of infection for Bird Flu viruses.
For more information on this topic, please check www.cdc.gov and the www.who.int.
