Avian Flu and Pandemic Flu: The Difference – and the Connection
There are many different types of influenza viruses circulating in the world at any given time. Some only infect birds, some only infect swine, and others infect only humans.
The term "bird flu" or "avian influenza" refers to influenza strains that affect birds.
One particular avian strain, known as H5N1, has caused severe illness in birds in recent years. Hundreds of millions of chickens and ducks have died or been killed in an effort to control this strain of influenza, yet the H5N1 virus has still been found in birds in many parts of the world. The virus is probably being spread by wild birds, which may or may not become ill when infected. Domestic poultry is very susceptible to H5N1.
Although the H5N1 virus primarily affects birds, it can also spread to people. Most people who have gotten the virus work directly with poultry or have had close contact with birds. That usually means direct contact with live birds or bird droppings. So far, it does not appear that people can get it easily from each other.
Public health experts are concerned that the H5N1 virus could change (mutate) into a form that is easily spread from one person to another. We don’t know for sure whether that will happen – or when it might happen. But if it does, the result could be a global influenza pandemic. Since few, if any, people would have any immunity to the new influenza virus, it could spread around the world very rapidly, causing serious illness in many people.
There is no sign right now that the H5N1 virus has become a pandemic strain. But if it does, it could cause a pandemic like the one that happened in 1918, when millions of people died, or it could cause a less severe pandemic, like the ones that happened in 1957 or 1968. We simply don’t know. But we need to be prepared in either case.
Most health officials believe that a pandemic will happen – it’s just a question of when.
WHO, CDC, and MDH are on constant lookout for the first signs of a pandemic emerging so steps can be taken to try to contain it.
The numbers keep changing. Check these sources to get the latest information.
Avian Influenza Statistics
Latest case counts for humans, plus lists of countries affected by H5N1 in birds.
Influenza Frequently Asked Questions
WHO (World Health Organization) overview of avian influenza, the effects on birds, and the possibility of H5N1 becoming the next influenza pandemic for humans. Attention: Non-MDH link
- Avian Influenza (Bird Flu)
CDC provides background information about avian influenza, including recent outbreaks, the viruses, and the risk to human health. Attention: Non-MDH link
- Key Facts About
Avian Influenza (Bird Flu) and Avian Influenza A (H5N1) Virus
CDC fact sheet describing bird flu, including definitions, transmission, symptoms, treatment, and risk to people in both Asia and the United States. Attention: Non-MDH link