A study at Duke University found that nurses’ scrubs, especially the sleeves, were contaminated with bacteria. They also took samples from the patient room environment and found the most contamination on the bed rails.
Mostly, it seemed from the research, that the transmission occurred from the patient to the nurse and from the environment to the nurse. You can read more about it here.
I like to wear a jacket to work, but I take it off before I do anything with patients. The thought of icky stuff on my sleeves gives me the heebie jeebies. I can scrub my arms clean in the sink but if my sleeves get dirty, they're dirty all day. I hate the thought of my sleeves getting wet or slimed. I know many nurses who feel the opposite, they wear long sleeves just so the ickies get on their clothes and not their skin. In fact, I know some nurses who don’t like to have to layer up, so they just wear sleeves to cover their arms at work.
Either way, I know all of us are either taking off our scrubs in the garage or tearing past family members to get to the laundry room and out of those bug-covered uniforms as soon as possible after every shift.