. . . . "You may become infected if you: Are exposed to a family member with giardiasisDrink water from lakes or streams where animals such as beavers and muskrats, or domestic animals such as sheep, have left their wasteEat raw or undercooked food that has been contaminated with the parasiteHave direct person-to-person contact in day care centers, long-term care homes, or nursing homes with people who are" .