A school girl did a wonderful science project - comparing the number of bacteria in the ice they serve you versus the number in their toilet water at fast food restaurants. Her answer is quite unappetizing as she discovered that in most (70%) locations there were more in the ice than there were in the water. Ugh. I do remember that when I was in Pakistan the leader of a detachment of seabees building terrorist defenses at the American Consulate told me how he was fanatic about keeping ice machines clean and disinfected because they could cause illness pretty easily. And don't even get me started on soft-serve ice cream dispensers.
Beware the people who compare the number of bacteria on some surface to the number of bacteria on a toilet seat -- they are misleading you with that comparison because the toilet seat has the fewest number of bacteria of any location in a bathroom - mainly because peoples butts and thighs (and yes, urine) don't have a lot of bacteria on them, and the (toilet) seats are routinely disinfected. And besides, you can only get skin type infections in the parts of your body that come into contact with the seat, at least if you're using the toilet properly that is. Generally, toilet seats are down right sterile compared to most other surfaces you regularly come into contact with. If the number of bacteria bug you, stay off the floor of a public restroom.
But the important thing isn't numbers, but variety of bacteria. For instance, should you be grossed out by that figure of 3 million bacteria on a computer keyboard? Well, when you consider that your very own personal body has 10 times more bacteria than you have cells, or a whopping 100 trillion (give or take a few trillion), that 3 million on the keyboard is insignificant. What matters is if there are any pathogens and your own general health since a lot of stuff that is normally harmless will turn on you if you let your guard down. It doesn't take many salmonella to ruin your day.
The best defense against bacterial invaders are clean hands and clean food. The 100 trillion that are already there will take care of the stragglers.
