OMG SWINE FLU!!!!!!!!!!!?

Hey , today in school I got this long tak on swine flu . And I was a bit confused as to why we have to sneeze/ cough into a tissue even if we haven't got it , like can you catch it from someone sneezing or coughing even if they dont have it? Also my friend was saying something about a disease that was going around china from the people spitting on the ground? Does anyone know what that is about|? thanks#