The CDC warns samples of the bird flu virus show signs of mutations that could make it more transmissible to humans. The CDC says it appears the H5N1 virus contained mutations in the Louisiana patient who contracted the nation’s first severe case of the illness.

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.

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,