An individual who was infected with the first severe case of bird flu in the U.S. has died, Louisiana health officials said on Monday. The name of the patient was not released; however, the individual was said to be over the age of 65 and had underlying medical conditions.Health officials revealed that the patient was hospitalized in mid-December after being exposed to "non-commercial backyard flock and wild birds." The Centers for Disease Control and Prevention said testing indicated the virus had mutated when compared with samples taken from infected birds.RELATED STORY | Bird flu kills 20 wild cats at a sanctuary in WashingtonTo date, there have been 66 confirmed human cases of bird flu in the U.S., but no human-to-human transmission. The CDC maintains that the public health risk is low. Most of these cases have resulted in mild symptoms for patients in the U.S. and a full recovery. However, past cases of bird flu in humans in other countries have been severe, with some resulting in death, according to federal health officials. Prevention measures include avoiding contact with sick or dead animals, in particular wild birds, and poultry.RELATED STORY | Pet food recalled after testing positive for bird flu