H5N1 (Bird Flu)
- H5N1 (Bird) flu remains a serious concern with the potential to cause a deadly pandemic. H5N1 (Bird) flu is an influenza A virus subtype that is highly contagious among birds. Rare but lethal human infections with the H5N1 (Bird) flu virus have occurred.
- Humans have little or no immunity to the H5N1 (Bird) Flu. Since November 2003, over 500 cases of human infection with H5N1 (Bird) flu viruses have been reported by more than a dozen countries. Some 60% have died.
- H5N1 (Bird) flu infection in humans is very rare and has never been detected in the United States. To prevent infection with H5N1 (Bird) flu, take precautions when visiting areas known to have H5N1. Avoid close contact with infected birds or their surroundings.
- The World Health Organization (WHO) is coordinating the global response to human cases of H5N1 (Bird) flu and monitoring the threat of an H5N1 (Bird) flu pandemic.
What is H5N1 (Bird) flu?
H5N1 (Bird) flu virus is an influenza A virus subtype that is highly contagious among birds, and can be deadly to them. The H5N1 (Bird) flu virus does not usually infect people, but rare infections with these viruses have occurred in humans. Nearly all human cases have resulted from people having direct or close contact with H5N1-infected poultry or H5N1-contaminated surfaces.- Symptoms of the H5N1 (Bird) flu virus in humans have ranged from typical human influenza-like symptoms (e.g., fever, cough, sore throat, and muscle aches) to eye infections, pneumonia, severe respiratory diseases (such as acute respiratory distress), and other severe and life-threatening complications. The symptoms of H5N1 (Bird) flu may depend on which virus caused the infection.
How Many Humans Have Been Affected by H5N1 (Bird) flu?
- Since November 2003, over 500 cases of human infection with highly pathogenic H5N1 (Bird) flu viruses have been reported by more than a dozen countries in Asia, Africa, the Pacific, Europe and the Near East. Indonesia, Vietnam and Egypt have reported the highest number of H5N1 (Bird) flu cases to date.
- Overall mortality in reported H5N1(Bird) flu cases is approximately 60%. The majority of cases have occurred among children and adults aged less than 40 years old. There have been very few cases of human-to-human transmission. Flu recipients in such cases have all died and there was no further spread.
- Highly pathogenic H5N1 (Bird) flu viruses have never been detected among birds or people in the United States.
More information on the global reach of H5N1 (Bird) flu:
World Health Organization (WHO) situation updates
World Health Organization (WHO) cumulative reports of human cases
H5N1 (Bird) Flu Prevention and Treatment
- Most cases of H5N1 (Bird) flu infection in humans have resulted from direct or close contact with infected poultry or surfaces contaminated with secretions and excretions from infected birds.
- The U.S. government carefully controls domestic and imported food products, and in 2004 issued a ban on importation of poultry from countries affected by avian influenza viruses, including the H5N1 (Bird) flu strain. This ban still is in place. For more information, see USDA's Animal and Animal Product Import
- You cannot get H5N1 (Bird) flu from properly handled and cooked poultry and eggs. Even if poultry and eggs were to be contaminated with the virus, proper cooking would kill it.
Follow the same advice you always would for properly cooking eggs and poultry:
| Wash your hands with soap and warm water for at least 20 seconds before and after handling raw poultry and eggs. |
| Clean cutting boards and other utensils with soap and hot water to keep raw poultry from contaminating other foods. |
| Use a food thermometer to make sure you cook poultry to a temperature of at least 165 degrees Fahrenheit. Consumers may wish to cook poultry to a higher temperature for personal preference. |
| Cook eggs until whites and yolks are firm. |
- If you plan to visit any of the countries that have had confirmed human infection with H5N1 (Bird) flu, visit Avian Flu & Travelers from CDC for advice on travel preparation.
- Some of the prescription medicines approved in the United States for human influenza viruses can be effective in treating H5N1 (Bird) flu in humans. H5N1 (Bird) flu is resistant to amantadine and rimantadine, two antiviral medications commonly used for influenza. Two other antiviral medications, Oseltamivir (TAMIFLU®) and Zanamivir (RELENZA®) would likely be effective in treating H5N1 (Bird) flu, but additional studies still need to be completed to demonstrate their effectiveness. It is important to note that H5N1 (Bird) flu infection in humans is very rare.
- The seasonal influenza vaccine does not provide protection against avian influenza.
- The U.S. Food and Drug Administration (FDA) approved the first vaccine to prevent human infection with one strain of the H5N1 (Bird) flu virus in April of 2007. The H5N1 (Bird) flu virus is not a pandemic virus (because it does not transmit efficiently from person to person). As a result, the H5N1 (Bird) flu vaccine is being held in stockpiles rather than made commercially available to the public. Should circumstances change, it will be distributed if needed. More information about H5N1 (Bird) flu vaccines.
H5N1 (Bird) Flu Global Monitoring
The World Health Organization (WHO) is coordinating the global response to human cases of H5N1 (Bird) flu and monitoring the threat of a H5N1 (Bird) flu pandemic. Epidemiologists use monitoring data to predict where and how disease might spread. It is important to know where disease outbreaks not only begin in the world, but also how and where they might spread in the United States. A primary goal of flu monitoring is to identify any outbreak of human-to-human transmission quickly so health officials can attempt to contain and control the outbreak.
- Global Influenza Surveillance (World Health Organization)
- Global Health Observatory Map Gallery (World Health Organization)
- Situation Updates - Avian Influenza (World Health Organization)
