Here is an excellent discussion on hospital infection rates in today's New York Times, Doctor Leads Quest for Safer Ways to Care for Patients.
I remember a situation back when I worked in the hospital. We had a patient with a bad wound, and the resident would go in, remove the dressing without washing her hands first OR putting gloves on. She'd then go on to do things to the wound, then leave--again, never washing her hands before going to the chart to write her note.
Our therapy team finally approached the resident and told her she was going to have to start washing her hands before and after seeing this patient. She was shocked that a bunch of lowly therapists and social workers would dare confront her on this issue, and told us she was the RESIDENT and knew better. When we threatened to get the infection control nurse involved, she backed down and started washing her hands.
I've also seen a nurse fool with a patient's IV, again with no gloves, get blood all over her hands, and go on to the next patient without washing her hands.
So, you are well within your rights to always ask medical personnel to wash their hands and put gloves on before they do anything to you. And don't even get me started on neckties!