Avian Influenza ("Bird Flu")

Avian influenza (sometimes called "bird flu") refers to influenza A viruses found in wild and domestic birds. Birds transmit the viruses to other birds via infected respiratory secretions and droppings. Avian influenza strains are divided into to two categories based on virus properties and the severity of disease seen in infected birds:

Low Pathogenic Avian Influenza (LPAI) infection in birds causes no or mild disease. Indicators of LPAI in a flock include ruffled feathers and a decrease in egg production. Because the symptoms are mild, LPAI in a flock may not be detected. An example of a well-known LPAI is influenza A H7N9 identified in flocks in China.

High Pathogenic Avian Influenza (HPAI) infection in birds can cause severe disease that is often fatal, especially in poultry populations (chickens, turkeys, phesants). The disease is often identified when disease or deaths in a flock or bird population prompts testing. The most well-known HPAI strain is influenza A H5N1 that has been seen in flocks in Asia and Europe. Of note, the H5N1 virus recently identified in birds in the United States is different than the Asian H5N1 virus that has been identified in birds and, rarely, humans in contact with birds for the last decade in Asia, Europe, and Africa.

Both LPAI and HPAI strains have been identified in birds throughout the world.

Avian Influenza in People

Rarely, influenza in birds can be transmitted to humans. Both LPAI and HPAI strains have been identified in humans. The vast majority of people that have been found with to be sick with an avian influenza virus have close contact with infected birds. Avian influenza viruses do not transmit readily from person to person. Only a small handful of person to person avian influenza transmissions have ever been identified in people with extremely close contact with another case. However, epidemiologists around the world keep close watch on these infections in case an avian influenza virus mutates and develops the ability to transmit readily between human hosts. People have little or no immunity against the influenza viruses that circulate among birds, so avian influenza that can be transmitted readily from person to person could potentially cause an influenza pandemic.

High Pathogenic Avian Influenza in the United States

In the last few years, high pathogenic avian influenza identifications in birds in the United States have increased. Both wild birds and commercial flocks have been affected. The most recent detection in a commercial flock in North Dakota was in April of 2015.

Recommendations for People:Most human infections with avian influenza occur after direct or close contact with infected birds. People should avoid handling sick or dead birds or wildlife. If contact does occur, wash your hands well with soap and water, and let your doctor know about your contact if you develop a respiratory disease after your contact with sick or dead birds. Poultry Farmers and people hunting birds should also let their doctor know if they have had contact with ill birds in the 10 days before developing a respiratory illness.

Recommendations for Health Care Providers: Recommendations for North Dakota Providers are outlined here. Currently, the Centers for Disease Control and Prevention (CDC) recommends that avian influenza be considered by health care professionals as a possible diagnosis in people with influenza-like illness (ILI) that have had recent contact with sick or dead birds, especially in areas where the virus has been identified. The North Dakota Public Health Laboratory can test for avian influenza. Rapid and commercial influenza tests (including RT-PCR) are not designed to identify novel influenza strains, and results from these tests can be misleading. For this reason, these tests should not be relied to preliminarily identify or rule out avian influenza strains in people. Influenza antiviral prophylaxis can be considered for people with a known or likely exposure to avian influenza viruses. Please contact that North Dakota department of health for dosing information. Extensive CDC guidance on identification and testing for avian influenza for public health and health care professionals can be found here. Possible infection with an avian influenza virus is immediately reportable via phone call to the North Dakota Department of Health Division of Disease control (701-328-2378); specimens must be submitted to State Public Health Lab for conformation or rule-out.

Avian Influenza Resources