By coughing on other people and spreading germs. Even coughing into your hands can spread disease. That hand you coughed into may open a door 5 minutes later and be touched by someone else who may then have the germs to spread around.
I think you mean: Contagious Diseases. these diseases can be transmitted though air, body fluids, water, food, and even things we touch. There are many different contagious diseases which each have...
No chiggers can not spread and neither can the rash. But you can find chiggers in a grassy area. And it comes around the rainy summer time.
Off your clothes, yes. Once they are in place on the skin,...
Yes malaria can be spread to another person by using the same needle or syringe. Only if the infected human's blood gets into you will not get malaria :D