liver flukes, how do we get them, and how do we stay rid of them?

Now I've started flushing these things out I want to know more about them. Is it from eating red meat that I have liver flukes? If so, most people probably have them right? If I stop eating meat will I be able to keep them out of my system? Does a simple parasite cleanse like Barefoot dewormer or humaworm get rid of them all?