The patient in Louisiana who was hospitalized with severe bird flu illness was found to have a mutated version of the virus, the U.S. Centers for Disease Control and Prevention (CDC) announced last week.
The fact that the virus mutated within the patient suggests that it could potentially spread from human to human.
The CDC analyzed samples of the H5N1 virus that were collected from the patient, comparing its genomic sequences to those of infected dairy cows, wild birds, poultry and other animals, the agency stated.