Diseases can spread very fast and they can become air borne by people sneezing when you have a disease like the flu
Diseases can be very fatal, most
diseases can kill people like ebola, aids
etc but unfortunately some can not be
cured where as some can
Diseases can spread in 3 ways, through particles in the air, in food that isn't cooked properly and through cuts in your skin
you have 2 lines of defence in your body, the first line of defence are scabs that form over a cut, your first line of
defence for the flu is mucus blocking all the bad stuff that trys to get past, the first line of defence for uncooked food
is in your stomach as the acid in your stomach will destroy the bacteria