I've heard people use different words for tis type of things, like most of the people who answered here : Clean-freak and Germophobia. However, I was curious about the right one so i'd probably go for the OCD "Obsessive Compulsive Disorder", it fits for the person you are talking about for it has many types like people with OCD tend to check things constantly , and some tend to contaminate and clean their belongings, so for your question it's the contamination part.
Contamination – the need to clean and wash is the compulsion, the obsessive fear is that something is contaminated and/or may cause illness, and ultimately death, to a loved one or oneself.
Refer to this for more
So basically the contamination part is connected to fear. Meaning, a person tends to over-clean whatever surrounds them with the fear that if they do not clean them, something might happen and that's the fear part.
It's some sort of phobia I'd say.