Chika, it's likely just old and stained. Get a spray bottle of Lysol and spray/wipe it down, along with all horizontal surfaces (tables, counters, furniture,etc), bathroom surfaces and doorknobs once daily. Regardless of whether they should be doing it or not, you'll feel better if it's done and you see it done.
When my dad was in the hospital I wouldn't let anybody in his room without them washing their hands with soap and water, including putting a note on the door saying so. I did not allow them to use hand sanitizer, as it is ineffective against viruses such as norovirus. "Sorry folks, we can't risk infection at this critical time."
And don't forget to wash your hands every time you leave the room and come back for any reason.
