Avian influenza is a strain of influenza virus that mostly infects birds. It is often called the bird flu.
In Asia and Africa, some bird flu has infected people. H5N1 is a strain that can cause serious illness and death.
Bird flu is caused by a certain influenza type A virus. The virus is common among wild and domestic birds. It rarely infects humans. Sometimes the virus can mutate (change). This allows it to infect humans.
The virus is passed through contact with an infected bird's:
People do not get bird flu from eating well-cooked poultry or eggs. The virus rarely passes from one human to another. When it does, it is usually a weak version of the virus.
Things that raise the risk of bird flu are:
Symptoms of bird flu may be:
More severe infections can lead to pneumonia or serious organ failure.
The doctor will ask about symptoms and past health. A physical exam will be done. The doctor may ask about close contact with infected poultry or recent travel.
A nasal swab or blood tests can be done to look for the virus.
There is no cure for bird flu. Antiviral medicines can help ease symptoms and the length of illness. Medicine work best if started within 48 hours of the first symptoms.
The overall risk of getting bird flu is small. To help reduce the risk:
There is a vaccine to protect against H5N1 in adults aged 18 to 64. It will be made available if there is an outbreak.
Centers for Disease Control and Prevention
US Department of Agriculture
Avian influenza A virus infections in humans. Centers for Disease Control and Prevention (CDC) website. Available at: https://www.cdc.gov/flu/avianflu/avian-in-humans.htm. . Accessed August 24, 2021.
Lycett SJ, Duchatel F, et al. A brief history of bird flu. Philos Trans R Soc Lond B Biol Sci. 2019;374(1775):20180257.
Pandemic influenza. Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/flu/. Accessed August 24, 2021.
Viral culture- influenza A virus. EBSCO DynaMed website. Available at: https://www.dynamed.com/lab-monograph/viral-culture-influenza-a-virus#SUSPECTED_AVIAN_INFLUENZA_A. Accessed August 24, 2021.
Last reviewed July 2021 by EBSCO Medical Review Board David L. Horn, MD, FACP Last Updated: 8/24/2021