(Bird Flu, H5N1 Infection)
Avian influenza is a strain of influenza virus that primarily infects birds. It is often called the bird flu.
In Asia and Africa, there have been cases of avian influenza that have the ability to infect humans. The most significant of these avian influenza strains is called H5N1. This strain can cause serious illness and death.
Virus Attacking Cell
Avian influenza is caused by a specific influenza type A virus. The virus is common among wild and domestic birds, but rarely infects humans. Occasionally, the virus can mutate which allows it to infect humans.
The virus is passed through contact with an infected bird’s:
- Saliva or blood
- Nasal secretions
Avian influenza is not contracted through eating well-cooked poultry or eggs. The virus rarely passes from one human to another. When it does, it is usually a weakened version of the virus. Infections are being monitored to see if the virus mutates in a way that allows it to easily pass between humans.
Close contact with infected poultry increases your chance of avian influenza. This may include domestic or wild ducks, geese, chickens, or turkeys.
Your chance of infection is also increased with recent travel to an area known to have avian influenza. Avian influenza outbreaks are most common in Asia, the Middle East, and northeast Africa.
Symptoms of avian influenza may include:
More severe infections can lead to pneumonia or serious organ failure.
You will be asked about your symptoms and medical history. A physical exam will be done. You will be asked if you have had close contact with infected poultry or have recently traveled to an area known to have avian influenza.
Nasal or respiratory secretions or blood can be tested for the presence of the virus.
Antiviral medications can help decrease your symptoms and the length of time you are sick. They do not cure the flu. The sooner the medication is started the more effective it can be. Ideally, the medication should be started within 48 hours of the first symptoms.
The overall risk of getting avian flu is small. Steps to help you reduce your risk include:
- Get a yearly flu vaccine. This is the best step to prevent an infection with influenza virus.
- Avoid traveling to areas where there are avian influenza outbreaks. For the latest travel information, visit the CDC's Traveler's Health page.
- Avoid contact with potentially infected poultry. This includes farms or open air markets.
- Wash your hands often if you are in an area where exposure to the influenza virus is possible. Be sure that hands are washed before preparing food. Use a hand sanitizer if clean water is not available for washing.
The Food and Drug Administration (FDA) has a vaccine to protect against H5N1 in adults aged 18-64. It will be made available in the event of an outbreak. Vaccinations can protect the individual and may control the spread of the infection.
US Centers for Disease Control and Prevention
Flu—US Department of Health and Human Services
Canadian Medical Association
Avian influenza A virus infections in humans. Centers for Disease Control and Prevention (CDC) website. Available at: http://www.cdc.gov/flu/avianflu/avian-in-humans.htm. Updated June 21, 2012. Accessed August 28, 2014.
Avian influenza in humans. World Health Organization website. Available at: http://www.who.int/influenza/human_animal_interface/avian_influenza/en. Updated August 30, 2011. Accessed August 28, 2014.
Cornelissen LA, de Vries RP, de Boer-Luijtze EA, Rigter A, Rottier PJ, de Haan CA. A single immunization with soluble recombinant trimeric hemagglutinin protects chickens against highly pathogenic avian influenza virus H5N1. PLoS One. 2010;5(5):e10645.
H5N1 avian flu. US Department of Health and Human Services Flu website. Available at: http://www.flu.gov/about_the_flu/h5n1/index.html. Accessed August 28, 2014.
Kilany WH, Arafa A, Erfan AM, et al. Isolation of highly pathogenic avian influenza H5N1 from table eggs after vaccinal break in commercial layer flock. Avian Dis. 2010;54(3):1115-1119.
Weir E, Wong T, Gemmill T. Avian influenza outbreak: Update. CMAJ. 2004(5);170:785-786.
Last reviewed August 2015 by David Horn, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.