having served as an altar boy prior to Vatican 2, I find your statement slightly hilarious. One of the great stories we would have for our class mates that morning in school, or after the weekend if we served on Saturday or Sunday, was the result of those occasions in which Father would draw a string of spit from someone’s mouth.
It isn’t an issue of “need to touch the tongue”; it is an issue of how often the priest does touch the tongue. I have received on the tongue often enough, and I served often enough to know that it is a regular occurance.
Frankly, if it were an issue of passing germs, Communion on the tongue is at least as likely to pass germs as receiving from the Cup. Folks, finger to tongue contact just plain happens; pretending it doesn’t, or saying “it is not necessary” (as if that had anything to do with the real world events) doesn’t change the fact.
The short of it is that I have yet to see a documented case of anyone catching anything that can be traced to receiving on the tongue or from the Cup. Christ gave us the Eucharist in the fashion e did; do you not trust Him?