<a href=https://explorable.com/cause-and-effect>Establishing Cause and Effect</a>. Cause and effect is one of the most commonly misunderstood concepts in science and is often misused by lawyers, the media, politicians and even scientists themselves, in an attempt to add legitimacy to research.
You can't catch cancer from anyone, in any way. Cancer is not contagious. You can't catch HIV/AIDS just by touching somebody. The AIDS virus is not found in sweat. Yes, you can catch a cold, or the flu by shaking hands with someone if you then put your hands on/near a mucous membrane (eyes, nose, mouth).
Wash Your Hands-The single most important way to prevent the spread of infectious diseases is to wash your hands. Most infections, particularly the common cold and gastroenteritis, are contracted when our germ infested hands come in contact with our mouths.