I live in Florida and use branches from outside without doing anything to them except cutting them to size. I've been doing this for years and haven't had any parasite issues, at least none that have come up on periodical fecals. I don't consider it a big risk, especially if I use live branches that aren't infested with grubs, spiders, or anything else that lives in dead wood. But you can always bake branches at a minimum of 350*F for 15+ minutes if you are worried and that should get rid of pretty much anything.