The genetic analysis of the H5N1 avian flu virus in specimens from the nation's first severely ill hospitalized patient in Louisiana reveals mutations that may enable upper-airway infection and greater transmission, concludes a technical summary from the Centers for Disease Control and Prevention (CDC).

The Centers for Disease Control and Prevention (CDC) has identified mutations in the H5N1 bird flu virus that may increase its ability to infect humans. These mutations, found in the hemagglutinin (HA) gene,

The CDC has confirmed a total of 66 human cases of bird flu across the United States as of Friday, although the number is believed to be higher.