In Brief:
Can you recall what your mom did when you had measles? An example of this is chicken pox. You must have read about the outbreak of bubonic plaque in India and the Ebola virus in Zaire. On the other hand, The deadly Ebola virus was said to be transmitted only through direct contact with the victim's blood or other body fluids. The same as when someone has measles or chicken pox --- the victims must be separated or isolated from the healthy ones.