Are stomach parasites contagious?
Contagious means something can be passed from one person (or animal) to another. Yes, the parasites would need to be passed through his vomit or feces, but… …he will get microscopic amounts of vomit and feces on his hands just from wiping that stuff off. So he will need to practice very thorough handwashing (including under the fingernails) to avoid giving it to someone. So if he prepares food for you, make sure his hands are very clean first, because it could go from his hands into the food, into you.
