Avian flu strains tend to only affect birds, but the current outbreak has spread to cattle and – in rare cases – people. The ...

Just as swine flu strains tend to infect pigs ... Some of these genetic mutations cause no immediate differences, while others alter some key viral characteristics. Influenza viruses mutate ...

A dangerous bird flu, in other words, was suddenly circulating in mammals—mammals with which people have ongoing, extensive ...

Influenza A/H1N1 can infect both humans and animals, including birds and pigs, and is one of several strains related to seasonal flu outbreaks. A colorized transmission electron micrograph shows swine ...

Influenza viruses mutate in a special way called reassortment ... Both swine and avian influenza are strains of influenza A. Just as swine flu strains tend to infect pigs, avian flu strains ...

Just as swine flu strains tend to infect pigs ... to sick birds or other sources of infection. Influenza viruses mutate in a special way called reassortment, which occurs when multiple strains ...