You're implying that in the Eucharist, Catholics eat dead, diseased flesh that transmits disease?
Not any more than Caths believe they are eating animal flesh by consuming the Passover Lamb, as an analogy does not need have complete one to one correspondence.
And endocannbalism is a practice of eating the flesh of a human being from the same community (tribe, social group or society), usually after they have died, and in the case i provided, it was to gain life properties of the deceased. Whether all the flesh was eaten or not then it still is endocannbalism, and was seen among pagans.