In truth, the most common way that the flu is spread is the result of person- to- person contact, as well as from dirty hands that touch your face- especially your eyes, nose and mouth that become portals of entry for the virus.

FORBES: Can Your Smartphone Spread The Flu?

Of all the ways to get in touch with London's history, sticking your nose in a sewer might not seem the most appealing.

BBC: In search of London's lost rivers