What do we call a person who is obsessed with cleanliness?

Is there any word for a person who is very , very much concerned about cleanliness and keeping things hygienic and even point out faults in clean things and explaining that they were dirty ?

I would probably call that person a neat freak. They also might have obsessive compulsive disorder.

In pathological terms an ablutomaniac.

You could say a number of things: anal retentive or just anal, neat freak, OCD referring to obsessive compulsive disorder, or "stickler for x"

Anal can describe someone who is clean to the point of it becoming a problem, however it is commonly used it in an exaggerating sense.

Neat freak is just as another poster mentioned, but it is an AmE colloquialism.

OCD is similar to anal in the sense that people are obsessed about keeping things neat, or in whatever way they think things should be.

Stickler is a word you might not see very commonly but if you mention it to a native English speaker they should get your gist.

I'll give some examples:

Take your shoes off, man. My wife is really anal about making sure nobody wears shoes in the house. Alternatively: My mom was always anal retentive when I was growing up; if she didn't know where I was at all times she would call me and have me give a status report.

He's such a neat freak, every time I drop a few chips while eating the guy whips out his handheld vacuum and cleans them up.

I'm so OCD about my cups that I order them from shortest to tallest in the cupboard.

You might also consider the word fastidious, though it refers more to one's meticulous nature than cleanliness directly.