 The barns these employees were working in were sweltering, which made it hard for employees to use their usual protective equipment. Large industrial fans were also likely turned on in the facilities, and officials say this probably didn't help as the fans moved around dust and feathers from infected birds, which can pass on the virus. So far, five people have tested positive. That makes this the largest number of workers known to be infected in connection to a single farm. The Centers for Disease Control and Prevention says the threat to the public is low.