Would anyone like to comment on whether G. lamblia/G. duodenalis is
transmitted between humans, dogs and cats, or whether strains/sub-species
are host-specific?
And when hikers get Giardiasis by drinking water from beaver ponds, what
species is it?
Animals have been infected with Giardia of human origin on a few
ocsasions and circunstancial evidence suggests that humans have been
infected with Giardia from beavers or muskrats. Antigenic and isoenzyme exams
could not distinguish between Giardia of human or animal origin.
In my opinion, there is no doubt that Giardia is a zoonotic infection.
How important the animal source is as compared to the human source is still a
matter of debate. It seems to me that, under normal circumstances, most human
infections are acquired from another human.
Only three species of Giardia are accepted nowadays: G. intestinalis
(= G. lamblia) of humans and other mammals, G. muris of rodents, birds, and
reptiles, and G. agilis of frog tadpoles.
tomato
trotted out the usual tree-huggers who are opposed to this wonderfully
effective and safe method of sterilizing food. Food and Water, Inc. is
probably the most ignorant group, saying that "irradiation introduces
chemicals and mutations into the food" - call them and voice your opinion
at 1-800-eat-safe.