Federal health officials say that not only has a Louisiana resident contracted the first severe case of bird flu in the U.S., but that the virus likely mutated in the patient. The findings raise concern regarding the adaptability of the virus.

Samples from a hospitalized patient in Louisiana show changes that could make the H5N1 virus spread more easily between humans

H5N1 usually spreads to people through contact with infected or dead birds, as with the Louisiana patient. Currently, there are no known cases of human-to-human transmission, said the CDC's Dr. Demetre Daskalakis.

There have been reports of bird flu cases throughout the U.S. and one confirmed case in Louisiana. Here's what the CDC says about bird flu infections.

A genetic analysis of viral samples from a patient in Louisiana hospitalized with the first severe case of bird flu showed mutations that may result in the virus becoming more transmissible

A person in Louisiana has the first severe illness caused by bird flu in the U.S., health officials said Wednesday.

In a case first reported in Louisiana, a patient has now developed the first known case of bird flu so severe as to require hospitalization.

A person in Louisiana has contracted the nation's first severe case of bird flu after the virus mutated inside their body, allowing it to more easily infect their upper respiratory system. Dr. Celine Gounder explains.

A patient in Louisiana became severely ill after contracting Highly Pathogenic Avian Influenza (HPAI), the US Centers for Disease Control and Prevention (CDC) announced in a statement on Thursday. This is the first serious case of bird flu affecting a human reported in the US since the outbreak began.