Giardia is a protozoan parasite that lives in the intestine of infected humans and animals (in particular, beavers and domestics animals like cats and dogs). It is found in the environment on surfaces (where it can survive for long periods), water and food that has been contaminated with the feces from an infected person or animal.
Children are more commonly infected than adults. The following have been implicated in both small and large community outbreaks:
FoodWorld 