A mutated strain of the flu is surging worldwide, sparking concerns about a severe flu season in the U.S. Here's what to symptoms to look out for.

One person had died from the disease. In early January, a backyard flock keeper hospitalized with bird flu in Louisiana became the first person in the United States to die of the disease after contracting the virus’s D1.1 variant. The person was over 65 and was reported to have underlying medical conditions.