In twenty years as a parish priest I served communion about 3,000 times, at a guess, and at each service I took the elements last. That means drinking after uncounted thousands of people. I never caught anything from that.
Granted, my experience in that area is limited to people who were probably pretty clean, for the most part. I don’t doubt that unsanitary conditions are breeding grounds for disease, but I don’t think we need to be obsessive-compulsive about it!