A contagious strain of bird flu that has stricken hundreds of birds across dozens of states has been detected in a human in the US for the first time, NBC News reported today. The patient, a worker at a commercial farm in Colorado, tested positive for the H5N1 flu and has experienced only one symptom, fatigue. He is being treated with the antiviral Tamiflu. Despite concerns that a mutated version of the virus could spread through human populations, only one other human case has been detected worldwide, and that person, who raises birds, is asymptomatic, according to NBC News. The H5N1 virus now circulating has been found in commercial and backyard birds in 29 states and in wild birds in 34 states, NBC News said, citing the US Centers for Disease Control and Prevention.