If Lawrence says that giardia can be transmitted through breastmilk, I
am amazed.  I haven't had a chance to check, but I think this is
*extremely* unlikely.  This is a protozoa, it is huge.  How would it
get from the mother's gut, to the milk?  How would it get into the
milk?

There is evidence that breastmilk is protective against giardia.

Jack Newman, MD, FRCPC