The CDC's analysis revealed changes in the hemagglutinin (HA) gene, a critical component for the virus's ability to attach to host cells. The mutations "were not found in virus sequences from poultry samples collected on the patient's property, suggesting the changes emerged in the patient after infection," the CDC stated in its December 26 update.

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

A genetic analysis suggests the bird flu virus mutated inside a Louisiana patient who contracted the nation’s first severe case of the illness, the U.S. Centers for Disease Control and Prevention said this week.