This is one of several buffet etiquette questions which came up on a recent holiday. When in a buffet queue (line) how should you respond to someone in front of using their hands or a serving spoon meant for (and previously used for another dish) to serve themselves?

This is not in and of itself a health and safety question, though there is the issue of meat spoons used in vegetarian dishes. Rather it is a matter of courtesy as not everyone likes their flavours mixed, or their food handled by others. 

Do you confront them with a polite reminder of health issues, or that you don't appreciate them handling the food? Or is it best to ignore it, and just ask staff to provide clean utensils or a fresh "uncontaminated" offering?