Avian Influenza

Note: the widely publicized Asian H7N9 avian influenza, or "bird flu", is not present anywhere in North America.  There have been no records of positive tests in wild or domestic birds, or cases of human illness in the US.

Avian influenza, commonly called “bird flu”, is an infection caused by type A influenza viruses that normally only infect birds.  The pathogenicity or ability of avian influenza viruses to cause disease in domestic poultry (chickens, ducks, and turkeys) tends to vary with the makeup or subtype of the virus.  Subtypes that are classified as “low pathogenic” cause no noticeable disease or only very mild symptoms of illness in birds, such as ruffled feathers and a drop in egg production.  Low pathogenic bird flu viruses are widely distributed in wild birds all over the world and do not pose a significant animal or public health threat.

This is the first time this virus has been seen in people.  Symptoms include fever, cough, and shortness of breath.  Infection with the new virus has resulted in severe respiratory illness and, in some cases, death.  Chinese authorities are conducting animal and human health investigations to learn more about this situation.  Available evidence suggests that most people have been infected with the virus after having contact with infected poultry or contaminated environments.

CDC is following this situation closely and coordinating with domestic and international partners in a number of areas.  More information will be posted as it becomes available.

For more in-depth information on “bird flu”, click on the avian influenza fact sheet or go to the links for national and international resources providing current updates on avian influenza in birds and humans.  For information on pandemic influenza, please visit our pandemic influenza page.

Avian Influenza Fact Sheets and Information:

Avian Influenza Fact Sheet (100k pdf)

 Avian Influenza Hoja Informativa - Espanol (123k pdf)

Bird Flu & You (62k.pdf)

External Avian Influenza Resources:
 
National Wildlife Health Center (USGS)

Avian Influenza (USDA)

World Organization for Animal Health Influenza (OIE)

Avian Influenza (WHO)

Avian Influenza (CDC)

Novel Influenza Testing Protocol (H5N1 Avian Influenza)