JoAnn has a cold. She is coughing up mucus (a respiratory secretion). JoAnn's lungs are the in the chain of transmission. The mucus from her cough is the
in the chain of transmission.

This is quite easy you just have to use a bit of brain power this was discovered in the Middle Ages the way to fix said sickness is by bloodletting it is very efficient and has a 100% cure rate cause you can’t have it if your dead

You did not show us the image of the burger, but i shall try to answer as best i can.  when purchasing food, always consider the ingredients as well as the person who prepared it. consider if they were hygienic people or not, in case the burger was infected with bacteria. no mortal should place an infected burger into their mouth.   

Little kids are eat dirt all the time so im sure you are fine