Possible Clues:

• Respiratory infection caused by a virus
• Winter virus disease, even birds get it
• It came flying in and finishes a thing I'm sick of
• Viral disease that is highly contagious
• Viral complaint
• Highly infectious viral disease
• Nasty viral disease, usually of winter
• Viral disease
• Tends to go viral in Tube from New Zealand to America
• In tube going down country with a sort of sickness