[Rob!]

I went for an STD test recently (I'm free of ailments before anyone starts ) and there is a particular part of the test that you have a throat swab with. The reason it's there is because people share things like straws when they're taking some drugs that you sniff. A lot of the stuff in things like Coke can actually cut your nose as it's going up so it's actually possible to catch an infection from someone if their blood touches yours.