A genetic analysis of samples from the patient in Louisiana recently hospitalized with the countrys first severe case of H5N1 bird flu show the virus likely mutated in the patient to potentially become more transmissible to humans, but theres no evidence the virus has been passed to anyone else.The patient was infected from sick and dead birds in a backyard flock, the US Centers for Disease Control and Prevention said in an analysis Thursday. The mutations the agency identified in samples taken during hospitalization werent found in the birds, suggesting they arent in the virus widely circulating in wildlife.The mutations, similar to ones observed in a hospitalized patient in British Columbia, Canada, may make it easier for the virus to bind to cell receptors in humans upper respiratory tracts, the agency said in its analysis.The changes observed were likely generated by replication of this virus in the patient with advanced disease rather than primarily transmitted at the time of infection, the CDC said. Although concerning, and a reminder that A(H5N1) viruses can develop changes during the clinical course of a human infection, these changes would be more concerning if found in animal hosts or in early stages of infection when these changes might be more likely to facilitate spread to close contacts.The agency emphasized the risk to the general public has not changed and remains low, but said the detection of the genetic mutations underscores the importance of ongoing genomic surveillance in people and animals, containment of avian influenza A(H5) outbreaks in dairy cattle and poultry, and prevention measures among people with exposure to infected animals or environments.