Bird flu is caused by a type of influenza virus that rarely infects humans. More than a dozen types of bird flu have been identified, including the two strains that have most recently infected humans — H5N1 and H7N9. When bird flu does strike humans, it can be deadly.
In recent years, outbreaks of bird flu have occurred in Asia, Africa and parts of Europe. Most people who have developed symptoms of bird flu have had close contact with sick birds. In a few cases, bird flu has passed from one person to another.
Health officials worry that a global outbreak could occur if a bird flu virus mutates into a form that transmits more easily from person to person. Researchers are working on vaccines to help protect people from bird flu.
Sept. 25, 2014
- Ferri FF. Ferri's Clinical Advisor 2015: 5 Books in 1. Philadelphia, Pa.: Mosby Elsevier; 2015. https://www.clinicalkey.com. Accessed Aug. 8, 2014.
- Mandell GL, et al. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa.: Churchill Livingstone Elsevier; 2010. https://www.clinicalkey.com. Accessed Aug. 8, 2014.
- Thorner AR. Avian influenza A H7N9: Epidemiology, clinical manifestations, and diagnosis. http://www.uptodate.com/home. Accessed Aug. 7, 2014.
- Thorner AR. Avian influenza A H7N9: Treatment and prevention. http://www.uptodate.com/home. Accessed Aug. 7, 2014.
- Avian influenza: Fact sheet. World Health Organization. http://www.who.int/mediacentre/factsheets/avian_influenza/en/#. Accessed Aug. 10, 2014.
- What consumers need to know about avian influenza. U.S. Food and Drug Administration. http://www.fda.gov/Food/ResourcesForYou/Consumers/ucm085550.htm. Accessed Aug, 15, 2014.
- Mertz D, et al. Populations at risk for severe or complicated avian influenza H5N1: A systematic review and meta-analysis. PLOS. 2014;9:1.
- Key facts about influenza (flu) & flu vaccine. Centers for Disease Control and Prevention. http://www.cdc.gov/flu/keyfacts.htm. Accessed Aug. 15, 2014.
- Prevention and treatment of avian influenza A viruses in people. Centers for Disease Control and Prevention. http://www.cdc.gov/flu/avianflu/prevention.htm. Accessed Aug. 15, 2014.