User blog comment:Lia Schiffer/435: Panic at the Dollhouse/@comment-44061-20110204043111/@comment-3344282-20110204145231

It is a bit pointless to continue arguing about this mother/father issue. For me it seems reasonable to assume that Isshin is the key, since being attacked by hollows kind of comes naturally with being a shinigami. I like Morpheus´ and Aeron Solo´s idea to call it an infection and actually compare it to an STD. Others don´t. Anyway, Ichigo himself is as clueless as we are, and I am certain that one of the next chapters will add an explanation which we will have to accept once it is canonical.