1..What's this mysterious noise

A Hospital in Miyagi Prefecture, Japan, was abandoned about 5 years ago and is now being rebuilt due to the lack of space in other hospitals nearby. There was this tale that was passed around from people around Japan about an old patient in the abandoned hospital. His was named Patient Zero. Why was he called Patient Zero? Read on to find out ;)

Reminder: I do NOT own the characters in the story, although I do own the plot :)