For several years recently my parish had a regular member who was dying of AIDS. I can't tell you how many times parishioners followed this man in the Communion line without any qualms about receiving the Mysteries after him. Our priest even offered those of weaker faith an out if they insisted on not receiving Communion from the same spoon as our AIDS patient, even though HIV is also not known to be communicated via exchange of saliva. Our priest is also very good, though, about saying that, to his knowledge, no communicable disease has ever been transmitted via reception of the Holy Gifts. "How can the very Fount of Immortality be the vehicle for disease and death?" I often hear him ask during cold and flu season.
(Our resident AIDS patient has since succumbed to his infections and died.)
If you think about it, the Priests should be the ones becoming most ill in the parish, since they must consume the gifts after everyone else has had the spoon touch them... But they're not.
"O Cross of Christ, all-holy, thrice-blessed, and life-giving, instrument of the mystical rites of Zion, the holy Altar for the service of our Great Archpriest, the blessing - the weapon - the strength of priests, our pride, our consolation, the light in our hearts, our mind, and our steps"
Met. Meletios of Nikopolis & Preveza, from his ordination.